Building for Tropical Climates...best method to withstand environment [Archive]

RodB

01-12-2005, 03:18 PM

Per Ron W's recommendation I started this post...

Building a boat for tropical climates, pro and cons of different methods, what holds up and what doesn't ...RonW

Climates like in Florida and Texas. Lots of heat and lots of humidity. Boat kept in saltwater year around.

Is there any issue that you get more different answers ... kinda like Doctors, each NA you talk to you get a different answer.

When you take into considertion the horror stories of boat deterioration in hot humid areas, BUT many traditionally built boats last several decades in such environments... What to do, what to do. Then, you hear horror stories of epoxy composite boats too...

Macnaughton recommends sheathed-strip construction according to his scantling rules... dynel sheathed decks... an encapsulated hull.

Reuel Parker lays out his own construction method, where the exterior of hulls are sheathed and painted with LP....with the interiors sealed with thinned epoxy and painted with linear polyurathane (LP).

Gartside is against strip-planking and suggests double planking ..sheathing the exterior of the hull. I am not sure he suggests sheathing the interior of the hull, just sealing it and painting.

And many say that traditional wooden boats are fine with good ventilation and maintenance.

I lean towards the totally encapsulated hull and decks... but what do I know. I'm just a would be boat builder contemplating my next project.

This should be an interesting thread.

RB

[ 01-12-2005, 11:29 PM: Message edited by: RodB ]

rbgarr

01-12-2005, 04:10 PM

To check on how a 'Gartside method' built boat has fared in Texas, get in touch with the owner of this boat:
[URL=http://www.yachtworld.com/core/listing/pl_boat_detail.jsp?currency=USD&units=Feet&checked_boats=1045025&slim=quick& ]http://www.yachtworld.com/core/listing/pl_boat_detail.jsp?currency=USD&units=Feet&checked_boats=1045025&slim=quick&[/UR L]

[ 01-12-2005, 05:11 PM: Message edited by: rbgarr ]

RodB

01-12-2005, 04:41 PM

I emailed the broker for the contact information of the owner of the Gartside boat to try to get feedback on how that boat has stood up...
RB

Billy Bones

01-12-2005, 05:15 PM

This going on 3 threads is getting hard to deal with.

Anyway, I can speak only from experience and observation, but I've done a fair amount of observing to base my statements on.

So, just down the road from me they build Gold Coast Yachts ( http://www.goldcoastyachts.com ) for the charter trade, mostly. They launch one every couple of weeks. They just launched a GC70 which was (and it pains me to say this) beautiful. These boats are in service every day. They are stripped in plywood and encapsulated in epoxy and glass, or so they were last I visited. Many of the ones in service now have been in DAILY commercial service for decades, here in the tropics where bottom paint lasts a few months and the tradewinds blow strong and steady.

Remember that you guys in FL TX and NC don't get heat and humidity until I'm done with it and send it your way. At N17deg with an annual water temp between 78-83deg (higher in marinas) we grow just about everything bad for boats here.

Traditionally built boats do not last in this climate, period. Their virtue is that they are more easily repairable, except that few in the leeward islands know how to do a satisfactory job of it. Just yesterday a traditionally planked boat got towed to the railway because she was going down. Sad.

Strip planking, where the attitude taken is that of a carvel boat, only with smaller planks, do not last. Down here where the salt blast rusts my hinges at 400'ASL and even stainless steel rusts, and anything touching aluminum forms a battery thru galvanic action, edge fasteners are a death sentence. Considering that plank openings on carvel boats are the source of most plank-on-frame failures, it doesn't make sense to suggest that treating strip planked seams like carvel seams will be in any way satisfactory let alone better, as you merely increase the linear footage of seams by a factor of about 4 on the average boat.

About cove-and-bead strips, you will get better more uniform glue coverage on a tight cove and bead joint than on a loose one. Good joints are better than bad ones.

As for repairability, a strip/sheathed hull is repairable in the same way any monocoque structure is. It isn't as easy as backing out screws and spiling in a new board (never done it but all the old hands delight in making it sound easy) but it isn't difficult.

If you skip all the chat and actually observe what's been working and for how long, sheathed strip/cold molded wins hands down in terms of saltwater miles travelled in the tropics, even over fiberglass. (discounting steel and aluminum, perhaps)

Somebody asked: "what exacly is IIRC ???" = If I Recall Correctly.

Cheers.

RodB

01-12-2005, 05:26 PM

Thanks BillyBones... I may quote you from time to time.

What you have said is what I have pretty much heard in the past...but you do get opposing feedback constantly, especially when wanting to change construction methods.

What is your take on teak decks lasting down there. Can they be managed or is it folly to try?

Thanks for taking time to spell out the issue as you see it ........again...

RB

[ 01-12-2005, 06:27 PM: Message edited by: RodB ]

Jamaica Mike

01-12-2005, 09:29 PM

What are you building? Will you keep it in the water? On land on a trailer or dolly?

What particular concerns do you have?

JM

RodB

01-12-2005, 10:27 PM

30 foot cruising sailboat, kept in the salt water... year around..most likely in one of the canals behind a home in south Florida.

Concerns: Rot... anywhere in the boat. Lots of maintenance.

[ 01-12-2005, 11:44 PM: Message edited by: RodB ]

Billy Bones

01-13-2005, 10:22 AM

What is your take on teak decks lasting down there. Can they be managed or is it folly to try?Boy they're lovely. Some folks keep them up but some don't. If (like me) you're the type who cultivates the ability to be easily distracted from regular maintenance ;) you might choose another type.

After rereading my comments and others I should clarify a couple of points I made. First, I didn't include the legions of rental charter boats in the VI (especially the BVI) in my sweeping statement. I don't really count them as working pleasure craft in the same way that I don't count condos as houses--they just ain't. Still, if you add them to the mix the production fiberfleet wins hands down. I choose not to include them in my analysis because we're talking about owner-built or at least owner-ordered custom craft. Also, I spoke specifically of sail craft--an assumption I always make which sometimes comes back to me. Second, to understand why so many traditional vessels fail here one must understand a bit about life in the tropics: specifically that maintaining the gumption to keep up a boat is just hard to do here. When it's always summer, you always sweat, when the power goes out regularly but not predictably (like for 6 hours on Christmas Day and ALL LAST SUNDAY), when you try to maintain a job and family, when your island is OUT OF BUTTER FOR A FLAMING MONTH and CEMENT for SIX MONTHS!! (sorry, end of rant) finding the time and energy to varnish, particularly when you'll have to do it again next year, is just damned hard to do. Stateside folks who come here winters seem to have the energy and enthusiasm for boat maintenance often moreso than locals, but not by any means always. What I'm trying to say is that the universally high failure rate of traditionally built boats is not entirely intrinsic to the boatbuilding technique but rests equally on the shoulders of the owners for whom the high degree of maintenance required doubles in the caribbean while the necessary gumtion to carry it out usually recedes coorespondingly.

If any of you read the book Wooden Boats published a while ago about Gannon and Benjamin you'll recall Chrissy built by them for and with the help of Jonathan Edwards. He (Edwards) brought her here for years and she became a slip queen. She has been recently sold, or at least has left St. Croix (I'd love to hear where she went and what became of her.) Anyway, as was alluded to very delicately in the book, Edwards is very energetic, dynamic and driven, yet his attention span makes Drosophila look positively monastic. Chrissy's survival is a testament to G&B, and to angelique and silverbali, and to what I assume was Kirby's paint, as so far as I know she wasn't touched in the years she was here. I saw her at the park anchorage once in all that time.

Edited to add: Included in my analysis has been a fair amount of destructive testing. I'm speaking of hurricanes, of which I've seen an uncomfortably large number of abnormally high ferocity. It has been my habit, once home is secure, to walk the beaches and swim the reef to analyze what failed and why. Because of these observations I have confidently reversed some of my earlier preconceived ideas about construction techniques. These observations have encompassed perhaps 50 wrecks in 15 years.

I understand that what is for me direct observation is for any who read this merely anecdotal evidence--and should be taken accordingly. Still, a proper look at my metadata might help others to understand the conclusions I've reached.

cheers.

[ 01-13-2005, 11:41 AM: Message edited by: Billy Bones ]

Jamaica Mike

01-13-2005, 12:32 PM

Originally posted by Billy Bones:
...maintaining the gumption to keep up a boat is just hard to do here. When it's always summer, you always sweat, when the power goes out regularly but not predictably (like for 6 hours on Christmas Day and ALL LAST SUNDAY), when you try to maintain a job and family, when your island is OUT OF BUTTER FOR A FLAMING MONTH and CEMENT for SIX MONTHS!!Uh Huh. I feel your pain. Still, would you trade it for Minnesota?

JM

Jamaica Mike

01-13-2005, 12:34 PM

Originally posted by RodB:
30 foot cruising sailboat, kept in the salt water... year around..most likely in one of the canals behind a home in south Florida.

Concerns: Rot... anywhere in the boat. Lots of maintenance.I would encapsulate the whole thing. Be especially careful to avoid any topside areas where fresh water (rain water or condensation) can pool and penetrate.

PeterSibley

01-13-2005, 03:42 PM

If I may add a small addition.......
I think Queensland ,Australia rates as tropical or at least semi tropical.Lots of very hot sun,high humidity etc.I can quote one boat that I know very well.A friend built it while he was doing his apprentiseship 30 years ago, so it is a good test, the whole 30 years in the tropics including at least one voyage to the Solomons.

Conventionally built ,carvel on Aust hardwood backbone and frames.Planking CCA impregnated hoop pine planking.( hoop pine is similar to your Western fir,what we call Oregon pine in durability ) Ply deck, dynel sheathed. All copper fastenings,nails and roves.No electrics.Lead keel.Minimal dissimilar metals.

I saw here built,well built but not a million dollar job and saw here again recently after 15 years of poor maintainence and indifferent ownership.The only repairs reqired were replacement ,graving, of a rotted section in the aft starboard cabin side .No other rot.Fastenings good. No leaks that the new owner complained about.

I think the ply/dynel deck and the lack of electrolyis were the main reasons for her health, and her builder of course !

[ 01-13-2005, 04:45 PM: Message edited by: PeterSibley ]

Old Bingey

01-13-2005, 06:02 PM

The usual old-time method for building good sized well built vessels along the USA coast of the Gulf of Mexico was narrow, quarter-sawn bald cypress or longleaf pine planking edge set on single sawn frames of usually cypress or heart longleaf but some live oak crooks were used in the bilge futtocks and up in the bow. The keel and stern deadwood was usually longleaf pine and so was the transom. Live oak was sometimes used for the stem instead of pine. The lumber was carefully selected for close together annual rings and no sapwood was ever used. The planking was fitted tight-seam with no caulking except in the butts. Galvanized or plain wrought iron (not steel) boat nails and drifts were the fastenings in later boats but wedged live oak treenails were used before 1850. An example of a boat built like this is the little (40' LOD) centerboard schooner "Governor Stone" which has been in continuous use (under sail!) since 1877 without a major rebuild. The old Stone has always been on hard times and still is. Since it went out of commercial service as an oyster buy boat back in the early sixties it has been shuffled from one poverty stricken "maritime museum" after the other and currently belongs to the state of Florida. Even though the old boat has been designated a "National Historic Place" interest in putting the old man back to useful service is limited to a few fervent people. Last time I heard, the Stone was at Eden State Park west of Panama City on a mooring. I hope he weathered hurricane Ivan. You know Ivan destroyed the interstate 10 bridge there. Good luck, old man.

paladin

01-13-2005, 07:43 PM

Boy... this subject has been around and around a lot the last couple of years.....tana Mari was built in Thailand for hot humid climates and is just as nice as when she was launched....so if there's interest go back on some of the forum listings..she's sheathed strip plankes and still smooth.....

RodB

01-14-2005, 01:03 AM

Obviously many folks are fans of traditional construction...

The majority of information out there today on building for withstanding harsh enviornments...seems to push encapsulated construction, sheathed well with epoxy and fiberglass or a synthetic fabric.

One of the main issues left out these discussions seems to be the amount of maintenance not required on an epoxy composite boat. When properly built you read comments like "the properly encapsulated boat is really less maintenance then a fiberglass boat". But then...

I personally saw a boat left on the hard for 4-5 years... in a hot humid climate, she was encapsulated new construction. She was not covered well... the cockpit floor plus down into the lazzerette hatches...the icebox casing and even the interior of the hull had rotted... It was like the worst environment possible and without the boat covered well there was an intermittent influx of fresh water, lots of heat and humidity. This was new construction abandoned for a few years... What a mess! It made you have a few doubts about the capabilities of epoxy in worst case conditions.

To be fair, it should be said that even a plain piece of furniture in a garage can last many years without any problems just by being protected from the sun and rain.

I don't think this subject has been addressed with any kind of concensus in the big picture... because there seems to still be controversy across the board.

Perhaps there is a concensus on a few points: 1) well sheathed boats require less maintenance than traditional designs 2) many traditionally strip-planked boats have lasted a very long time...3) good ventilation is vital for any boat to survive very long without problems. 4) all boats require care to have any longevity at all. and 5) all things being equal the encapsulated boat with at least minimal care will do better in the harsh enviornment than a traditionally built boat.

RB

[ 01-14-2005, 02:09 AM: Message edited by: RodB ]

RonW

01-14-2005, 01:49 AM

Rod it would seem as if with your last paragraph that you have put a lot of thought and research into what construction method for your next boat, to with stand florida waters with out a lot of constant maintance.

I have been waiting for a reply that I don't think is coming.
I would have thought that the answer might be something like a multi chime - welded aluminum or welded steel hull. Of course with self bailing decks.With a nice paint job and wood cabins as well as much wood trim as possibly, you might be able to disguise it so no one would know.
Check out Ken Hankinson on the shrink wrap steel hulls.Look at some of the pictures of these boats on his site, like the tug boats, man it is hard to tell that they are steel.

http://www .boatdesigns.com/cgi-bin/store/web_store.cgi?page=materials-methods.html&&cart_id=1043511_8126 (http://www.boatdesigns.com/cgi-bin/store/web_store.cgi?page=materials-methods.html&&cart_id=1043511_8126)

Shrink wrapped steel....

http://www.boatdesigns.com/store/Html/Products/images/FREDMKARIRU2.jpg

http://www.boatdesigns.com/store/Html/Products/images/FREDMKARIRU5.jpg

[ 01-14-2005, 03:01 AM: Message edited by: RonW ]

Billy Bones

01-14-2005, 03:48 AM

The thing we're tiptoing around is that epoxy makes the difference. It is stronger and more durable than vinylester resin. It isn't perfect, though. It needs a good coat of paint to be waterproof and protected from the sun, which will kill it. Wood makes an excellent core material, provided it is the right wood. It has fewer problems than foam, cardboard, roving, and so on. And don't paint it a dark color or it will soften on a warm day, esp in the tropics.

Down here metal requires more maintenance than wood in hull construction, and that maintenance is a lot more expensive.

PeterSibley

01-14-2005, 04:31 AM

Well Rod,
looks as though you prefer the epoxy route.Which ever way you go remember the best preservative for a boat is use....lots of salt water ;) Easy to apply ,just sail. Leave it at a dock or tied to a quiet mooring and any (wood)boat will rot.

I recommend carvel cos its cheap,easy to repair and it works.Others have different recommendations ,fair enough...I have very little experience of the longevity of epoxy contruction in hot ,humid climates so I'll leave that to them . smile.gif

cheers,
Peter Sibley

Billy Bones

01-14-2005, 07:29 AM

Originally posted by PeterSibley:
Which ever way you go remember the best preservative for a boat is use....lots of salt water ;) Easy to apply ,just sail. Leave it at a dock or tied to a quiet mooring and any (wood)boat will rot.

I recommend carvel cos its cheap,easy to repair and it works.Others have different recommendations ,fair enough...I have very little experience of the longevity of epoxy contruction in hot ,humid climates so I'll leave that to them . smile.gif
Peter's point is well taken and is reflected in the article in the current WB about Thies Matzen and Wanderer III. I'm inclined to agree, too, where boats are sailed often and in varying climates.

Scott Rosen

01-14-2005, 08:34 AM

Purely anecdotal.

In the mid-60's, Fred Driver or Miami, Florida, began importing Sea Sailers from Hong Kong. Some of you who have read my posts know that a Sea Sailer is a 30 foot pilothouse sloop, teak planking over steam-bent ipol, copper fastened. All of the lumber for interior and exterior is teak. The deck is teak over plywood. The transom is molded teak over ply. All timbers are teak.

A lot of these boats have lived in Florida since the 60's. Mine lived in Florida from 1971 through 1992. These boats have held up very well. The areas of weakness, which have needed rebuilding, have been the plywood deck and the plywood portion of the transom. I've heard of no instances where there have been major repairs needed to the hull.

Current owners are covering the cabin top and replacing the deck with epoxy and glass or dynel.

It goes without saying that the owner needs to take care of the boat. All in all, I think many of you are not giving traditional construction with the best materials a fair shake.

RodB

01-14-2005, 01:59 PM

I agree with Scott to a great degree. You can bet that if I built traditionally, I would want to use mahogany for the strips because of its great record and its stability. Teak would probably be out of everybodys price range.

If your building traditional strip-plank and you are building a heavy displacement boat, the mahogany would be ideal. Proper fastenings, the best wood... lots of skill...sounds like a winner.

I still want to know how traditionally built teak decks stand up in the tropics....

RB

RB

Venchka

01-15-2005, 04:16 PM

Study how dhows are built around the Persian Gulf. I don't know the particulars, but I was there and I can tell you that no where will you find a harsher climate for boats. 100+ degrees and 100% humidity at 10pm. Blasted by UV during the day. Insane heat and constant humidity. Reinforced concrete structures near the ocean were falling apart after 20 years. The rebar was corroded and making the concrete crumble. The boats were in better shape. I doubt seriously if there is anything high tech used to build these craft. They hold together. They work hard.

Wayne
In the Swamp. :D

bainbridgeisland

01-15-2005, 08:26 PM

Here is someone with years experience building wooden boats expressly for the tropics. His company uses epoxy over cold molded timber with PAINTED SURFACES.
http://www.boatshop.com.ph/index.html

RodB

01-16-2005, 01:25 AM

Many traditional boats that were sailed all around the world have great records of survival but a thought occured to me earlier. When a boat is sailed long term and the owners are living aboard, you have to admit that such a boat gets pretty damn good care and with constant sailing the motion alone allows for significant drying of any water below decks and along the interior of the hull. In reality, most boats are moored or tied up at a dock and left sitting most of the time. This is the reality of the life of most boats and what they must endure... and those that are voyaging the majority of the time are much more likely to be cared for better and therefore suffer less deterioriation than those sitting at the dock months on end. Just a thought to consider when singing the praises of traditional voyaging craft that "stood up well" over time.

RB

PeterSibley

01-16-2005, 02:14 AM

If you are going to proceed with the epoxy path as a tropical maintainence solution ,one thing the the West people propose that I find problematic is practice of embedding load bearing fastenings in epoxy filled holes. In my experience epoxy becomes quite soft at the kind of temperatures that are often achieved on deck in tropical climes.The idea of having ,for instance , chain plates so attached is worrying.

Personally,if I were to build a wood /epoxy composite boat for our climate I would probably choose cold moulding for its slightly easier repairabily.I would also consider Aerodux as an adhesive over epoxy .

RodB

01-16-2005, 03:23 AM

Is West saying to completely seal the interior of said holes with epoxy for encapsulation sake... or having a larger clearance in the hole with a fairly thick volumn of epoxy surrounding the load bearing hardware?

I guess completely sealing the interior of the hole with two or three coats of epoxy and leaving room for application of a tough flexible polyurathane like 3M 5200 would be bad because with room enough to "work" , sooner or later you would have failure....

Cold molded building is the most expensive and most labor intensive... and easy to dismiss considering the positives of sheathed-strip (strip-planked and sheathing with fiberglass and epoxy) construction.

I would use Resurcinol for gluing up a mast...for sure...

RB

[ 01-16-2005, 04:32 AM: Message edited by: RodB ]

Billy Bones

01-16-2005, 06:04 AM

Originally posted by RodB:
Is West saying to completely seal the interior of said holes with epoxy for encapsulation sake... or having a larger clearance in the hole with a fairly thick volumn of epoxy surrounding the load bearing hardware? Get the book. It's cheap and incredibly informative.

About temp failures in epoxy...there was a brief but highly publicized period when cold molding was taking off when everyone wanted a coldmolded hull and everyone wanted to paint it dark blue. A few such craft sailed around the southern med and other warm spots, and they began showing seams and occasionally popping veneers, or so the stories went. Now it is known that these problems don't occur in light colored boats. Also, now, if you INSIST on a dark hull in the tropics, there are epoxies formulated for the purpose whose deflection temperatures are higher than dark wooden hulls can achieve this side of Venus.

Epoxy, like carvel planking, gaff sails and catboats, will always have its detractors, many of whom will make up stuff to dissuade you from its use. I think, however, that if you try to step beyond the chat, as I have, and observe for yourself what works, you'll be assured that the techniques are sound and the methods are proven.

good luck, over and out.

bainbridgeisland

01-16-2005, 10:53 AM

Originally posted by PeterSibley:
...In my experience epoxy becomes quite soft at the kind of temperatures that are often achieved on deck in tropical climes...Peter, all glues are sensitive to heat. As you point out, most of the epoxies we use for boatbuilding have low temperature capability. However, many epoxies have far higher temperature capability than the West system. The West system was formulated for easy application and use at a moderate price rather than for high temperature applications. There are many epoxies made expressly for service above 200 degrees F that have proven to be good boatbuilding adhesives.

bainbridgeisland

01-16-2005, 11:17 AM

Originally posted by RodB:

Cold molded building is the most expensive and most labor intensive... and easy to dismiss considering the positives of sheathed-strip (strip-planked and sheathing with fiberglass and epoxy) construction.
RBRodB, having professionally built many cold molded boats as well as strip planked boats; I completely disagree with your statement. Most folks I have met with this opinion have never become proficient at cold molding or are trying to build boats that were improperly designed for cold molding.

When designed correctly, cold molding is quite a bit faster than strip planking. By the way, carvel planking is quite a bit faster than either cold molding or strip planking.

Today, strip planking is popular. Nothing the matter with that, it is a good system for building a boat. However, speed is not its primary advantage. The primary advantage is the relatively low skill needed to plank. Cold molding takes more skill to be quick and carvel planking takes more skill than cold molding.

See this thread for more discussion on cold molded versus strip planking: http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=010150&p=

I believe both cold molded boats and strip plank boats have been proven to be suitable for long term use in the tropics. However, cold molding has a slight advantage in that it is made of thinner laminations. This puts less stress on the adhesive and the adjacent timber due to thermal expansion. By the way, marine plywood has these advantages as well and is more labor efficient to build with.

David Mancebo

RodB

01-16-2005, 12:25 PM

I have the Gougeon book, just not the latest edition. I probably should get it as this type of technology has progress and changes taking place. I was recenly reading their suggested method of gluing down 1/8" teak decks and was wondering if they would still recommend the same technique?

I have coldmolded an additional layer of 1/4" ply on my boat bottom with no problems, but I can certainly see why many many folks describe the 100% cold molded process with 1/8" veneer as very labor intensive and skill requiring...

Its probably like everything else, if your experienced, the process flows quickly for you simply because of skill level, however, there are many many descriptions of the process as "very labor intensive" requiring high skill in many instances...ie., a negative take... I have also read many comments on this forum where the builder states emphatically that they will not build cold molded again for various reasons.

That was why I was stating that it is easy to see why the less skilled/experienced would probably select the sheathed/strip method...it is easier to produce good results even if a bit slower...which I have never heard before. Also it would be less expensive requiring less epoxy and no veneer.

My thinking would be you have to compare apples to apples. How long will it take you to produce the same hull scantling thickness with each method (the same exact hull relatively) I would think the strip-planked hull to final fairing, sheathing, and final sanding would be a bit quicker and definitely easier for the uninitiated. I base this on several strong comments I have seen on the work and skill required for the cold molded process...not to mention the cost of veneer for the process compared to the strip-planked process....plus my own experienced strip-planking the 1 foot wide decks on my present boat.

RB
I recommend carvel cos its cheap,easy to repair and it works.Others have different recommendations ,fair enough...
cheers,
Peter Sibley

I don't think its all that inexpensive in the US today to find good quality lumber to not only carvel plank the hull of a boat but to finsih the interior traditionally... I would think it would significantly less expensive to purchase wood for strip-planking and epoxy composite construciton throughout....

rb

[ 01-16-2005, 01:57 PM: Message edited by: RodB ]

PeterSibley

01-16-2005, 02:43 PM

I don't think its all that inexpensive in the US today to find good quality lumber to not only carvel plank the hull of a boat but to finsih the interior traditionally... I would think it would significantly less expensive to purchase wood for strip-planking and epoxy composite construciton throughout....
Rod, I'll leave that calculation to you .Here in Australia good wood is readily available and quite cheap is you can deal with the mill directly.In my case I bought my planking in 28' and 30' lengths for about 30% of the cost of the combined epoxy and glueable timber quote for the same hull.(our hardwood is not suitable for epoxy glueing,resorsinol is OK).

Personally I'm sure that any good pine planking,probably impregnated ,as in fishing boats in your Southern states would prove very long lived.The problem of skill remains .

from bainbridgeisland
Peter, all glues are sensitive to heat. As you point out, most of the epoxies we use for boatbuilding have low temperature capability. However, many epoxies have far higher temperature capability than the West system. The West system was formulated for easy application and use at a moderate price rather than for high temperature applications. There are many epoxies made expressly for service above 200 degrees F that have proven to be good boatbuilding adhesive
Thanks for that information....good news,I didn't know high temp epoxies were available in suitable formulations.I would certainly recommend their use in a "tropical" boat,especially for loadbearing applications.

RodB

01-16-2005, 03:00 PM

The high temp epoxies would be great for Dynel sheathed decks in the hot enviornment but I doubt the rest of the internal structural joints would be at risk...and I bet the heat resistant epoxy is way more money....and probably not necessary in 99% of the boat applications.

RB

Meerkat

01-16-2005, 03:07 PM

This may or may not be relevent:
http://tropicalcruisinghandbook.com/

bainbridgeisland

01-16-2005, 03:57 PM

Originally posted by RodB:

...Its probably like everything else, if your experienced, the process flows quickly for you simply because of skill level, however, there are many many descriptions of the process as "very labor intensive" requiring high skill in many instances...ie., a negative take...

...My thinking would be you have to compare apples to apples. How long will it take you to produce the same hull scantling thickness with each method (the same exact hull relatively) I would think the strip-planked hull to final fairing, sheathing, and final sanding would be a bit quicker and definitely easier for the uninitiated...

rbEach time I have been able to talk to builders who complain about 'labor intensive' cold molding, it is obvious they were not skilled in the process. Don't get me wrong, many of these folks were smart people and skilled wood workers. Some were professional Boat Builders.

Many of the refinements that allow speed are not written down. You won't find them in a book. This is true for ALL building methods including strip planking. These are trade skills. Having worked with good crews skilled with both of these processes, I was able to learn the trade skills needed to produce both types of hulls quickly.

I do agree with you that strip planking is easier and materials usually cost less too. I just don't think it is faster.

I think you have made my point about designers with your comment: "the same hull scantling thickness with each method (the same exact hull relatively)" The same exact hull is different than the same hull thickness. Each particular building method has strength and weaknesses. Thus, trying to apply the scantlings of a carvel built hull to a strip planked hull would be incorrect. The same can be said for trying to use the exact same hull thickness, frame spacing, longitudinals and so forth with both strip planking and cold molding. When you note designers who do this, it usually means they have not taken full advantage of either building method. Thus, at least one if not both of the building methods will take more time to build than it should.

Think of it this way. The scantlings of a hull are calculated to resist certain loads. There are an infinite number of ways to do this. i.e. thinner planking requires closer spaced stiffeners and so forth. Thus boats can resist the exact same forces even though the hull thickness is different. The structure just compensates in other ways. This is the essence of scantlings. To try to force one hull thickness for all boats would not be a good comparison. Instead, good scantlings produce boats that can resist the same loads while taking best advantage of the materials and processes used.

David Mancebo

RodB

01-17-2005, 01:26 PM

Each particular building method has strength and weaknesses. Thus, trying to apply the scantlings of a carvel built hull to a strip planked hull would be incorrect. The same can be said for trying to use the exact same hull thickness, frame spacing, longitudinals and so forth with both strip planking and cold molding. When you note designers who do this, it usually means they have not taken full advantage of either building method.

You make a very good point, you must achieve the same scantlings with whatever construction method you use to make use of the advantages of said method or you would be overbuilding or underbuilding if you don't adjust the construction method to match the required scantlings...

This would be one of the reasons to have an NA help you fine tune scantlings to maintain the same hull characteristics of the original design...ie,. weight distribution, etc...

RB

John Meachen

01-17-2005, 03:17 PM

The concerns that have been raised over the strength of epoxies are probably not without foundation.To enable us to get a clearer picture,is there a forumite who can give us an assessment of therelative strengths of the wood and the glue?It may be that even after a 30% loss of strength,the epoxy is still quite a bit less likely to fall apart than the wood.Would limited post-curing help?

RodB

01-18-2005, 12:34 AM

I thought the following of interest and pertinent to this thread.... The author examined 5 boats thoroughly to see how they had withstood the test of time....all epoxy built...

A search on how epoxy built boats stand up to time showed up a great article called "Wood/Epoxy Longevity"

Entire article:
Wood/Epoxy Longevity (http://www.Epoxyworks.com/indexprojects.html)

The following summarizes the article.

Conclusions
From looking at these five boats, we can gain some insights about what promotes longevity in wood/epoxy composite boats.

* Strip planking with cedar or mahogany covered with fiberglass inside and out is very successful.
* Marine mahogany plywood works best. Fir is good, but cover with at least 6 oz fiberglass to prevent checking. Birch is OK above the waterline.
* Always coat exposed endgrain of plywood thoroughly.
* Douglas fir and mahogany are good choices for stringers. Not so good are ash, oak, spruce, and pine (especially if exposed to wet conditions and/or poor ventilation).
* Always use clear vertical grain wood. Avoid knots or knurly wood.
* Composite chines are much better than timber chines because aggregate buildup of materials results in dimensional instability and resulting checking at the corner.
* Heavy timbers necessary for successful engine mounts (noise dampening) should be made from laminations not thicker than one inch. Use mahogany. Large timbers (say 3" ¥ 6") of solid timber, especially oak, are a poor choice.
* Bonding hardware fasteners with WEST SYSTEM epoxy works well in both fresh and salt water.
* Strip planked rudder or centerboard foils covered with fiberglass work, whereas plywood is not a good choice.
* The centerboard axle arrangement described above works well long term.
* For painting topsides, use light colors. Two-part polyurethanes, like Awlgrip, are very good. One-part polyurethanes are a second choice.
* Don't use polyurethanes below the waterline if the boat will be in the water longer than a day. Use bottom paint.
* Natural exterior finish is high maintenance and not a long-term proposition.
* Teak veneered decks are nice, but they're hard to walk on when the sun is out and are high maintenance. Long term, they'll eventually have to be repaired or replaced. White, nonskid painted decks with a layer of 6 oz fiberglass cloth over plywood are a better long-term arrangement.
* Proper ventilation is important on wood/epoxy boats.

[ 01-18-2005, 03:58 PM: Message edited by: RodB ]

RonW

01-18-2005, 02:23 PM

Rod, there are some of the conclusions from the article that I do not agree with at least in my opinion.Such as.

* Douglas fir and mahogany are good choices for stringers. Not so good are ash, oak, spruce, and pine (especially if exposed to wet conditions and/or poor ventilation).

Oak and Pine, if it is red oak I agree not so good, but can't see that applying to white oak. As for pine if it is any of the white pines, I totally and whole heartedly agree not to use for frames or stringers, BUT if it is one of the yellow pines I dare to say they will outlast douglas fir by two fold at least and will outlast mohagony. Mahogany's have good rot resistance, some a lot more then others, but are not at the top of the list of rot resistance, it is just that all their qualities combined makes for a pretty good boat building wood.

* Marine mahogany plywood works best. Fir is good, but cover with at least 6 oz fiberglass to prevent checking. Birch is OK above the waterline.

For years I have made it a point of examining every plywood or wood boat I could that was built in the 60's and 50's(freshwater).Repeatedly I kept seeing the same thing, the douglas fir marine plywood would be in excellent condition, and might I add with nothing more then paint. But every time the mahogany ply, which was used for transoms, decking, railing and generally trim was rotted and delaminated and in not poor but gone condition.
I think mahogany has been over rated and would fare far better as planking then as a framing lumber, particularly in a wet and poorly ventilated area. There are a ton of so called mahogany's and I am sure there are big differences between them.

In the U.S. I would think some of the native woods that are the most rot resistant are black locust, white oak and southern yellow pine followed by white cedar and so forth on down the list. Being how you are in texas and are going to use the boat in florida, I fail to see how you could do better then using plain old southern yellow pine, readily available and at quite reasonable prices in the south eastern part of the united states.

[ 01-18-2005, 03:24 PM: Message edited by: RonW ]

RodB

01-18-2005, 02:28 PM

-------------------------------------------------------------------------
... one thing the the West people propose that I find problematic is practice of embedding load bearing fastenings in epoxy filled holes. In my experience epoxy becomes quite soft at the kind of temperatures that are often achieved on deck in tropical climes.The idea of having ,for instance , chain plates so attached is worrying.
Peter Sibley

-------------------------------------------------------------------------------------------
I took time to reread the Gougeon book on fastenings and Billy Bones is right...lots of great information, more than I remember... They have tested each type of fastener for shear and linear strength...failure. They have charts showing the increases you gain by bedding different types of fasteners with epoxy, especially larger ones such as chain plates. Epoxy bedded hardware failure is not an issue at all, they have tests to the nth degree to prove this is a well worked out science.

I didn't remember how sigificant the strength of the bond of fasteners was increased by surrounding the fastener with a bed of epoxy....pretty amazing what the failure tests show...I just knew they were plenty strong.

RB

[ 01-18-2005, 03:32 PM: Message edited by: RodB ]

RodB

01-18-2005, 02:38 PM

Ron,

I agree, long leaf yellow pine would be great ...
I was just quoting the article from "Epoxy Works", I

RB

RonW

01-18-2005, 04:11 PM

* LONG LEAF YELLOW PINE *

A little information on the yellow pine species that some will find interesting and very beneficial.
Long leaf and loblolly pine have been hailed by many resources, including the u.s. navy as being premium rot resistant woods for boat building, even being subsituted for white oak, as you can find referenced to in more then one boatbuilding book.
But trying to find some one that stocks either might be a problem. When you do find them, in clear, straight and vertical grain, you will also find that they command the price of from $8. to $10 a board foot.Right up there on the premium lumber list.
So what is yellow pine, or actually southern yellow pine. It is a group of 4 species that have been grouped together by the lumber distributors of america. These four species are almost identical in their qualities, and that is why there are only 4 species in this group. Their similar qualities are weight, rot resistnce, fastener holding, strength, flexibility, grain.
The 4 species are- longleaf pine- loblolly pine- short leaf pine- slash pine. Any and all of the 4 species will be mixed in the lumber stack that the lumber yard is selling under the heading of southern yellow pine.
I have no idea how to tell them apart, and seiously doubt if it matters, only if you are a perfectionist, and I doubt if you could see any real difference in this life time.The lumber is readily available to at least 2/3's of the u.s. There are different grades, most common might be #2 or construction grade, but #1 and clear is also available, and a lot of times you might be surprised as to very useable lumber for frames and such that is laballed as #2, particularly if your yard allows you to pick through the stacks. You can always pick your grain orientation yourself, as it is all there.
Yes it is plantation grown and usually averages 12 to 14 ring growths per inch on the average.
I think it is a far overlooked lumber for boatbuilding where weight is not the upmost of importance. For traditional building I think it would be hard to beat, as far as a long lasting hull.

RodB

01-18-2005, 04:34 PM

I thought is was usually recommended for use in building the backbone or deadwood.... etc.. What other uses would it be suitable for.

I used it for gluing cleats and deck beams in my skiff simply because it was available and less expensive than straight grain one by doug fir.

RB

Tristan

01-18-2005, 06:40 PM

I'm an amature builder, but I've built nine or ten boats in S. Florida for personal use. Also owned a couple more I didn't build. Built one sharpie using yellow pine, traditional const. complete with galvanized boat nails. It's great wood if you don't get it wet. Clear yellow pine you buy nowadays will almost certainly be kiln dried and it won't be quarter sawn and it will cup, rot, soak up water, etc. etc. etc. I learned that the hard way. I did, however, once find a long full two inch thick plank of resinous pine (don't know what kind) in a mangrove swamp and figured it was good aged wood. Made a rudder out of it (drifted together w/ bronze drifts) and it lasted forever, never showed a sign of wear or rot. Oh that one could walk into a lumber yard and buy wood like that! Marine plywood is pretty good, but will eventually rot if the ends ain't sealed. Fir holds up pretty well, a hell of a lot better than yellow pine. I've heard that cypress will soak up amazing amounts of water and perhaps become heavier than you wish. For the "tropics," (actually Miami and south Florida is consdered sub-tropical, especially tonight!) I've had very good results (and several friends have also had good results) with stripped planking (fir) encased inside and out with glass or polypropylene. Plywood decks and cabins (or strip planked cabin sides) similarly glassed. I've seen strip planked hulls that were not glassed on the inside have their seams open up in dry winter weather, hence glass inside too. Plywood is fine too, if it is encased in glass or polypropylene. Lowell P. Thomas

PeterSibley

01-18-2005, 11:49 PM

posted by RodB
They have tested each type of fastener for shear and linear strength...failure. They have charts showing the increases you gain by bedding different types of fasteners with epoxy, especially larger ones such as chain plates. Epoxy bedded hardware failure is not an issue at all, they have tests to the nth degree to prove this is a well worked out science.

Good to hear Rod....did they graph fastening temperature beside strength? What was the top temp rated ? I may sound suspicious ;) but only because I have often epoxy bonded bolts and threaded bar in my work.... the result is great and to get them out you just heat the rod and pull.This is the tropics remember.Metal can get too hot to touch on deck.With due respect to West (who have the best promotion dept I can imagine) if you are going to bond use one of the high temp epoxies mentioned above...just for those places ,won't cost much and you can laugh at me for being a born worrier ;)

RodB

01-19-2005, 02:19 AM

Thanks Tristan, exactly what I was looking for... boats that last in Florida. Shouldn't Honduras Mahogany strip planks (sheathed inside and out) be way better than Douglas Fir?? From what I've read, HM should be the best except for something like teak. Also, how does the commonly used cedar do in the same situation, sheathed stripped ...encapsualted per your experience?

With the cost of mahogany, its nice to know Doug Fir would perform great and it should be a bit less money.

Epoxy failure at high temps.... I definitely will look into higher temp epoxies for specific uses...you are right, Peter, the cost will be insignificant, but I wonder how hot a chain plate fastener will really get in direct sun....?

RB

[ 01-19-2005, 03:26 AM: Message edited by: RodB ]

Tristan

01-19-2005, 08:34 AM

Fir is mighty good wood for boat building. One plus is the fact that it doesn't seem to be real oily, hence takes resin well. That is always a consideration in hulls you intend to use resin on. I believe teak is pretty oily wood . Hondouras Mahogany is real nice wood, lasts well in the tropics, but costs a good bit more than fir I imagine. Philippine "mahogany" is NOT related to Honduras and tends to soak up water, a bit soft, but probably would be ok if covered inside and out w/ "glass". White Cedar, again, is a somewhat oily wood I believe. Don't know how it works with resin. Had a friend use clear cypress on a big (60') dory schooner, I think he double planked it, diagonal layer over inside longitudinal layer. Glassed pretty heavily on the outside, has lasted fine for 25 years or so, but inside seams tend to open a bit when inside of hull is real dry, close when more humid). Seems like you'd use teak, cedar, or Honduras mahohany in a boat you want to build carval planked, as the wood is long lasting, even in the tropics. I've seen boats in the Caribbean planked with "Cedro," (Cedrela odorata), another Honduras mahogany relative (we know it as "cigar box wood"), very aromatic, rather oily. Again, I'd recommend fir for a strip planked, fully sheathed boat for use in the tropics (or marine ply, sheathed where it is going to get wet, perhaps for a flat bottomed or hard chine deadrise boat). Of course fir planks would probably last pretty good in a properly maintained carval planked tropical boat too I believe . In the late 50's I saw a bunch of Bahama sloops, 25 to 40' in Nassau Harbor, they all used Pine Tar to coat and preserve the inside of the hull (which was probably native yellow pine from Andros, though I believe they did import fir sometimes. The pine tar is wonderful stuff. Traditionally Bahamians framed their boats with "Horse Flesh," a relative of the Honduras Mahogany. The old builders would take a dinghy to an island where they could find Horse Flesh, spend a few days cutting knees and frames, live on grits and fish they caught, and bring the load back to the building site. Re. pine tar, I bought a can just to smell. Used it years ago to tar the rigging of my Bawley Cutter. It's the tar that the "tarry sailor lad" tarred his pig tail with, the wonderful tar smell of tarred marlin. Again, the above is based on my life as an amature builder, gleaned from personal experience, travel in the Caribbean, and rubbing shoulders with other builders, both amature and professional. I ain't any pro. lowell P. Thomas, Naples, FL

RonW

01-19-2005, 09:29 AM

Sorry, But I do not agree with Tristan's description of southern yellow pine, or one of the 4 species I listed above. He may be describing one of the pine species, but I think there may be confusion as to which species.
If it was so prone to rot, why would boatbuilding books list it as a subsitute for white oak. Think you need to do a little more investigative work Rod.Cupping, warping, twisting and so forth has nothing to do with the species of wood, but rather with grain orientation, how it was cut from the log, and proper drying.

I have personally worked with southern yellow pine for 35 years, and can say from experience that it is one tough, strong and very rot resistant wood.All the framing in my boat is yellow pine, and the next one will be yellow pine frame and yellow pine strip planked.
As for a few examples of it's durability, or at least up north,can't say about the bahamas, but imagine the wood wouldn't know where it was.
A couple examples- all bricklayers around here use yellow pine 2x10's for scaffolding or planking to walk on and work off of on the brick bucks. They use it all year, leave it out in the weather, and at the end of the year they stack it up beside of the garage where it lays unprotected in the rain and snow, year after year. They don't paint it or even cover it up with a tarp. And most older bricklayers have scaffolding planks that are older then their kids. 20 years and more. Could say the same for foundation men.
This sure doesn't sound like a wood that is prone to rot. The boat that I have now, when I built it 2 years ago, I used 3- 2x8's that I had to cut up and make sawhorses from, just ripped them. They had layed in the mud next to the fence for 7 years.Totally unprotected. The wood was just fine. A lot of species of wood, there would have been nothing left to pick up, let alone use. A lot of the softer pines would fall under this category as well.
I stand on my statement that southern yellow pine is one tough wood and very rot resistant, about 40 lbs. a cubic foot.

Tristan

01-19-2005, 10:04 AM

Yellow pine, I suspect the key words here are "what kind of pine,how it is dried, and how it is cut." I believe the Andros Island Pine is Pinus elliotii, but am not sure. Lord knows what you get now from the various lumber supply houses. I gave up using much yellow pine following problems 35 years ago with a sharpie built of it. If you can get resinous, quarter sawn, air dried wood I imagine it would be ok, probably good. My experience is that it isn't easily find such. I do have some large 2 by 10 planks that I probably will use for a rudder, but the builders I know won't use it where it will get wet. Lowell p. Thomas, Naples, FL

RodB

01-19-2005, 01:35 PM

I have always thought very highly of yellow pine. Just using some yellow pine purchased locally in Dallas...it was as described in many publications. It seemed heavier and stronger than the Doug Fir I was also using for similar uses on my boat...just denser. I was using it simply because of availablitiy...and minimally due to its weight. Also I have read many instruction sheets on different boat's construction and yellow pine many times is listed as a choice for the backbone and deadwood as an alternative to oak.

I would think the drying method would be critical as kiln dried Douglas Fir is not even in the same ballpark with air dried...I think one must do solid homework to come up with quality building materials... period.

RB

[ 01-19-2005, 02:52 PM: Message edited by: RodB ]

Tristan

01-19-2005, 02:18 PM

As mentioned above in this thread, there are various species of pine that are called "yellow pine." In "Wood, A Manual For It's Use As a Ship Building Material," Vol. 1, Dept of the Navy, 1957, there are five species listed as "Southern yellow pine," these are Pinus palustris (Longleaf pine), P. echinata (shortleaf pine), P. taeda (Loblolly pine), P. elliotii (Slash pine), P. caribaea (slash or longleaf pine). According to the above manual, "longleaf" includes ONLY P. palustris. Real longleaf must be pretty good stuff, "Dense heartwood southern yellow pine is considered almost as decay resistant as white oak." Also from the above manual, "Dense southern yellow pine of structural grade is well suited for planking, keels, stems, stern posts, deck beams, and other structural members of ships. Southern yellow pine provides (prior to the late 1950's I suppose) much of the Nations general building and container lumber." Now, that said, if a builder can find (and assure they have found) heartwood Pinus palustrus or one of the other "structural grade (meaning boat structure)" yellow pines which is air dried and quarter sawn, by all means, try it. But if, like me, you have to rely on generic "yellow pine," and pay an arm and a leg for the clear stuff, hell, why not go with fir instead of taking a gamble. There just ain't that many virgin pine woods left that are filling lumber yards with high quality heart pine, quarter sawn from three foot diameter trunks and air dried in sheds for a couple years are there? Miami was initially built from planks cut out of huge Dade County pines (P. eliotii), and the planks had to be drilled for the nails cause either the nail would bounce off the wood and take an eye out or the plank would split. All those big trees have been gone for more than half a century, and I expect that's the case for most quality yellow pine. Lowell p. Thomas

[ 01-19-2005, 03:45 PM: Message edited by: Tristan ]

George.

01-19-2005, 04:15 PM

One word:

Ipê.

Lasts forever, even grounded in a tropical mangrove swamp.

RodB

01-20-2005, 01:49 PM

Tell us more about Ipe, such as sources, cost, history, and record of longevity on boats.

I have a friend who just built a deck behind his house with it...

RB

[ 01-20-2005, 02:50 PM: Message edited by: RodB ]

RonW

01-20-2005, 04:52 PM

I am sure that george can give you better and more precise info on ipe, but untill he comes back, My wood book says.
Ipe, a south american wood that is composed of 20 species, and weighs 64 lbs. a cubic foot. Sounds awfully heavy to me, if that is right, then it means the wood will not float, like ebony doesn't float.`It is strong, hard, and highly resistant to rot and insects.

On another note, I stole this from the building forum under -alca-

http://www.worldvoyagers.com/iwalani/boat/index.htm

You might find it interesting to note that the hull is made from douglas fir, oak, and yellow pine.Yellow pine used for frames and planking.
Rod there is a old saying, that when you have looked every where and can't find it, did you look in the back yard?

RodB

01-20-2005, 09:29 PM

Yes, the Ipe my friend used on his backyard deck was heavy...

I would pick Honduras Mahogany as my first choice to strip-plank a hull, but cost would be out of signt. If weight wasn't all that important then quality yellow pine would be ok... It seems Douglas Fir would most likely be 2nd choice since is is one of the strongest woods per unit weight. I have noticed cracks in Doug Fir so you would have to have enough to get good clear material for the entire hull. I guess cedar would be the next choice.

Everything based on availability.

RB

George.

01-21-2005, 08:15 AM

Ipe sinks in water indeed. VERY hard - you have to drill to drive nails into it. Oily - you need to wipe with acetone before glueing or epoxying.

Just about immune to rot - not only in boats, also in houses, decks, etc., even in a very humid tropical environment like here. No marine boring critter can bite into it, even with no bottom paint. There are hundred-year-old abused ipe hulls in Brazil, still going with almost no maintenance and leaky decks, no sign of rot. And I know of at least one ipe wreck which is half-buried in sand at the mouth of a stream in a beach near here - lives soaked in fresh water, has been there for at least 30 years, and has NO ROT.

And finally, most of it comes from second-growth forests - unlike mahogany and the like, you can use it with a clear coscience.

Pronounced ee-PAY.

Billy Bones

01-21-2005, 08:48 AM

I agree with George: ipe is great stuff. Be aware that it is VERY stiff and difficult to bend, and does not glue well. Solvents help, but it is so naturally hard and solid it has essentially no pore or grain structure--meaning no 'tooth' for epoxy or other adhesives to bite. In that way it is comparable to purpleheart. A sharp blade will burnish even a cross cut so that it looks like a french polished surface.

Originally posted by George.:
...snip... No marine boring critter can bite into it, even with no bottom paint. There are hundred-year-old abused ipe hulls in Brazil, still going with almost no maintenance and leaky decks, no sign of rot.

It is interesting to hear Georges observations on the point about borers. There seems to be some popular confusion about marine borers and ipe. As recently as a year or so ago, even Jagels in the WoodenBoat column about wood science noted it is susceptible to borers--one of its few shortcomings. I have heard supposedly knowledgable testimony both ways.

George.

01-22-2005, 06:43 AM

Down here, in addition to old boats, there are literally hundreds of decks and piers built using ipe underwater. Some are close to 40 years old. None are ever painted, and none ever get bored. And we have LOTS of marine borers - any suceptible wood left unpoisoned wont last a year in these waters.

RodB

01-26-2005, 01:37 PM

George,

I'm not sure whether you sheathed your hull exterior or not, I would assume not ...please comment.

Have you noticed any "creep" in the joints in your hull ...resulting in "print through"? This problem supposedly is minimalized if the construction takes a long time (amateur building) as the epoxy has plenty of time to harden up, shrink, and to do any "creeping" it may have a tendancy to do.

Per Macnaughton, even if hulls are properly strip-planked and sheathed (sheathed strip construction) print through can take place, usually on the side of the hull facing the sun. Usually the first time one resands and fairs the hull for repainting this all goes away permanently....per Macnaughton.

What would you estimate the relative weight of your hull (percentage difference) compared to a traditionally built hull carvel planked with honduras mahogany...as a reference point? Just wondered how much heavier your Ipe hull is compared to building her in the old carvel methods... of lighter woods than ipe or teak.

RB

George.

01-28-2005, 07:02 AM

I had lots of "creep," but only on the topsides - none underwater. It shows up in the summer, especially when we have a steady wind and Dalia only shows one side to the tropical sun day after day... and that is even though I did sheath the hull. But none of it seems to affect the structure, or penetrate more than a millimiter into the seams. Still, if anyone knows more about this I would like to hear it.

And I took years to build the hull, so slow building is not the answer. In fact it was worse before launching, since the boat was motionless in the sun and the whole hull was exposed, topsides and bottom, inside and out (before there was a deck). Just before sheathing I cleaned all the "creepy" seams and poured thin resin into them, just to make sure.

Re: weight, Dalia's hull and deck weigh 9.5 tons, carefully calculated, outside ballast excluded. Total displacement - 32 tons light, 35 tons laden, with 7.5 tons outside ballast and 7.5 tons inside ballast. I imagine traditional carvel would have been a bit heavier, as I would have used heavier frames. On the other hand, if I had built for lightness rather than strenght and paranoia ( ;) ) I would have used lighter frames and stringers, especially since she has 5 structural bulkheads, and might have gone with a 4cm hull instead of 5cm, so she would have been much lighter...

RodB

01-28-2005, 01:12 PM

I'm wondering if traditionally strip-planked hulls with edge nailing, with epoxy or white lead between the strips and NOT SHEATHED...have more of a problem with print through than sheathed....it seems like you would....

RB

carioca1232001

02-04-2005, 09:58 AM

Peter Sibley wrote:

Well Rod,
looks as though you prefer the epoxy route. Which ever way you go remember the best preservative for a boat is use....lots of salt water Easy to apply ,just sail. Leave it at a dock or tied to a quiet mooring and any (wood)boat will rot. Peter, I have taken the liberty to emphasise what you have said more than once on this Forum.

I hope I am not being silly, but just suppose that one´s boat was moored.

Would tipping a bucket or two of a saturated rock-salt solution in tap-water over the topsides ensure its preservation, if it were down on a weekly basis ?

The ocean in our bay is not exactly clean and I would not be too happy to tip some of the latter stuff over my topsides ;)