Building for the other extreme in climates!!!

[JohnE]

Hi,

As a new wanna be builder, I never dreamed that the tropics can be so hard on a boat. Now it has me wondering about my location. Unfortunately it is not the tropics!!

I live in the Mojave Desert of California (USA). All our lakes are dry lakes, but we have the ocean not far. We get months of 105F daytime temps and 90F nights. Then we get winter with the 30F temps at night. Needless to say it is dry (except this past week!!) It is not unusual to get less than 1in (2.5cm) per year, and not all at once.

I can not afford to climate control the boat house. Sun protection is obviously required, but heat and dry will happen.

I am considering building an 18-20ft open boat that is strip planked and glasses inside and out. Some of the comments on the web suggest this will not hold up in many climates.
(See this link for Paul Gartside's take on it: www.gartsideboats.com/faq2.php) (http://www.gartsideboats.com/faq2.php))

So guys and gals what are your opinions and related experiences with this problem.
Anything from construction tech and maintaining the boat to suggested designs would be welcomed.

What is the best construction method for me? I don't mind the work, but I don't want a maintenence nightmare.

Thanks!!!

John

[RodB]

I would think that if the wood you use to build is equilibrated in humidity with your surrounding atmosphere, then if encapsulated during construction, you should have no problems. You may have extremes now and then but overall you have a specific range of humidity and temp... that just happens to be drier than most other areas.

If the wood you build with has sat in this enviornment for awhile then it will be in a range of moisture content that reflects your enviornment and when encapsulated will not have very much differential from the same wood sitting around un-encapsulated. This would result in lesser differential forces pushing water by osmosis or duffusion into sheathed structures.

I might hot have said this very well, but you get the idea.

I would think stitch and glue, sheathed-strip, cold molded would all do fine for your use...all encapsulated construction...but I'm certainly no expert....

RB

[dmede]

another option might be glued lap ply. great looks and no shrinkng or swelling issues. well coated it should be fine out there.

[RonW]

Well I am going to get down on this one, in reguards to gartside's negative article on strip planking. On one hand he writes this article blasting the method, BUT yet on his site you would be amazed at how many designs he has that are built in strip planked. So what gives, if it is such a terrrible method, then why in the world has he designed all these boats to be built using the method. Sounds like contradiction to say the least.Thinks he needs to make up his mind as to where he stands. Second of all, if you look at his methods, at least some of them mix and match the method pretty badly, referring to strips with cold molding added, not one layer of cold molding but 2 layers, the most exspensive and labor extensive of all the so called strip planked methods.Quite frankly I don't think the man has spent enough time studying the various strip planked methods to fully understand the pros and cons of all the methods, and instead wants to group it into one negative heading. Again - then why has he drawed so many plans for the method.

Here is the other side of the argument if you want to read a little more closer to the truth.

http://www.macnaughtongroup.com/_disc5/00000078.htm

P.S. I suspicion that gartside wrote the article when he was pissed off due to something concerning a strip planked job, and probably has lived to regret his comments that where made at a poor time.

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

[JohnE]

Hi,

I don't know much about Paul Gartside, but he definitely did not like the technique. Not sure why he would us it so much. He did mention a couple of upsides to it, so maybe he just over did it in his article.

I did hear from Paul Selway (NOTE A DIFFERENT PAUL THAN THE GARTSIDE LINK) and he felt that while my climate was harsh on any tech., that it was no worse on strip plank than others and with proper care no more trouble. I tend to believe in Paul S's opinion, but am biased by my love of his designs.

I also agree that the key is getting the wood to be stable in the environment before building. That might make this climate better in that it will be very very dry when sealed. One problem is to avoid cracking and splitting while drying here.

I am not sure what thickness Paul S uses in his design or even what species he recommends. I will need to ask or order the study plans.

Really want to build that Baltic Lugger!!!

-- John
John

[Venchka]

Originally posted by dmede:
another option might be glued lap ply. great looks and no shrinkng or swelling issues. well coated it should be fine out there.DITTO!

Here you go.

Ernie Fasse is building a Caledonia yawl in Tucson, AZ.


Ernie in Tucson (http://www.mavc2002.com/cyforum/viewtopic.php?t=287)

Ken Leap is building the same boat in Portales, NM.

Ken in Portales (http://www.mavc2002.com/cyforum/viewtopic.php?t=147)

I know the climate in those locations doesn't exactly match yours, but they are about as close as I know of. You can ask Ernie & Ken about their experiences. From the photos they have posted, building is progressing just fine.

Wayne
In the Swamp. :D

[ 01-14-2005, 04:13 PM: Message edited by: Venchka ]

[JohnE]

Thanks Wayne!! I will definitely contact them.

[whb]

John

One thing to watch for is totally sealed interor locations. One fellow here (I think it was videoguy) had a sealed flotation area in the bow that exploded from the heat expanding the air insided.

I will be building for the desert in the Drumheller area of Alberta. Temperature range -40 celcius to +40 celcius. I plan to ensure that I have no compartments that will be totally sealed. A small 1/4" hole in each will allow the air pressure inside to adjust.

Howard

[Levi]

Hey John E....you do not seem to have a really serious delema according to most of the members who have given you a few great ideas.

I'm wondering what the humidity range will be when you take your rig to the ocean as opposed to where you are building it? If you would locate in ocean humidity for a lengthy stay, would that affect the build? I have laid lots of hardwood flooring and know how important it is to have the supply of wood laid out loose in the house for a week to 10 days before laying it. When the homeowner fires up the AC & furnace the hardwood floor gives & goes in each season. I love wooden floors & wooden boats but they are both greatly challenged by humidity changes. You are wise to be concerned about this and you should be able to address the problem and end up enjoying your build for many years. Good luck.

[RonW]

The honest truth of the matter is that Plywood is the most dimensionally stable wood and the one to be the least effected by abrupt mositure and heat changes. Possibly even one of the stitch and tape boats, Look at tolman's skiff or some of Sam devlin's designs.

You live in the mojave desert? I was through there about 8 years ago, I wondered then how in the world could anything live here? That is a honest to god desert. I could not handle it.
But more power to you. Would the epoxy get gooey? You defintely need to paint it white.

[ 01-15-2005, 05:08 PM: Message edited by: RonW ]

[Paul H]

A couple things to consider with epoxy. An epoxy sheethed boat, encapsulated if you will, is protected from water, but not water vapor. Think goretex, water is kept out, but water vapor can get through. Epoxy sheethed boats need to be stored in a ventilated area, and any areas of the boat sealed with hatches, need to have the hatches left open when the boat is in storage, or morage as the case may be.

The other issue is epoxy definately softens in the heat, but heat also assures a more complete cure.

I do agree that epoxy glass encapsulated ply is probably the most tollerant construction for diverse wether conditions. Tolman skiffs are stored outside in the winter, in areas that can drop down to -30 or -60 F, and with very low humidity. We can also have temp swings of 50F in 24 hours, I've seen it go from -15 one day, to +35 and raining the next.

Then when the snow melts, we hook the trailers up, and drive maybe a couple hundred miles to the water, run as fast as we can for the conditions to go get some fish, run back, drive home and wait for the next spell of good weather. I'd also say Tolmans don't necessarily get the TLC treatment as far as maintenance and repairs. The boating season is too short to be fiddling with the hull, and the winter is too cold.

Renn's earliest production boats have been in service for over 20 years, and I'd venture most are run hard and put away wet. I haven't heard of any material failures. You can go down to the Homer dock and find somewhere between a 1/2 dozen and a dozen moored up. I'd venture to say many of them have seen quite a few seasons of hard use.

[JohnE]

Thanks for all the good input. I was wondering how much epoxy will soften in the heat. I was planning on painting it for UV protection.

After this discussion, I am leaning toward plywood construction.

John

[Paul H]

Provided you keep the boat out of direct sunlight, I don't think there will be any problem with the epoxy softening.

The one thing that will be a pain is working with epoxy at high temps. I have the opposite problem, even with a heated garage, if it's -20 out, the garage isn't as warm as I'd like, and epoxy cure takes some time. With high temps, even a slow hardener will result in a quick cure.

Just remember, small batches and work fast.

[Bob Ketterling]

I built a Pooduck skiff (larger version of the Shellback) two years ago here in Southern California out of lap plywood and have had no problems with the plywood. The hull is painted semi gloss white and is holding up well. When I first pulled it out of the spray booth into the direct sun I thought the relection would blind me but I have had no problems when using the boat. I think you will be fine with either strips or plywood. Which ever way you go just keep it covered when not in use. My boat is outside under a couple of layer of blue plastic and is doing OK. I use the boat in local lakes and have had it in the ocean twice, Ventura Harbor and Newport back bay.

[RodB]

JohnE,

Just paint a light color and you will be fine.

FYI....Larry Pardey in his "adhesives appendix" in "Details of Classic Boat Construction: The Hull" talks about the Heat Deformation Temperature (HDT) of specific epoxies...

At 118 degrees F West System-Brand epoxy 105, with 205 hardener has lost 30% of its strength (www.concentric.net/-westsys/phisical.shtml)

At 123 degrees F (52 degrees C) System Three Epoxy resin has lost 30% of its strength (The Epoxy Book, by System Three Resins, pub 1998, page 37)

Some of the negatives listed by Pardey on epoxy as an adhesive:

... Loss of joint strength if used below 65 degrees F
...Can lose strength in temperatures above 101 degrees F.
...Applying warm epoxy to cold surfaces can cause condensation to settle on the adhesive before parts are mated and will give a low strength bond.

You just have to use products right....

RB

[RonW]

It would seem to me that if epoxy lost 30% of it's strength at 118 degrees, that would be all the reason that I would need to go with plywood on frame with metal fasteners and forget the stitch and tape idea altogether.

[RodB]

Maybe epoxy is so strong that a loss of 30% in most applications is not an issue...one of epoxy 's easier jobs is maintaining a seal around everything. ..which doesn't require much strength.

Sounds good anyway!

RB

[ 01-16-2005, 04:57 AM: Message edited by: RodB ]

[paul oman]

Use a warm weather epoxy so that as you build in the hot weather you will have a suitable hot life.

coat both sides of the wood as wood expands and contracts with moisture, while epoxy and other materials expand and contract with temperature.

paul oman
progressive epoxy polymers
www.epoxyproducts.com (http://www.epoxyproducts.com)

[RodB]

I think Pardey's main point was that in sheathing and glue up of hulls where you have ample layer thickness, etc epoxy does the job fine if used properly... but where it is only used as a glue, and the wood goes through wet/dry cycles/ epoxy is not as good as Resourcinol. He shows several laminated items that resided on the interior of a boat...that delaminated over many years...not so with resourcinol. It is an interesting read but certainly not definitive...and epoxy science is progressing and that is the crux of the matter. In many cases the problems of old are probably not the problems of today because of improvements in epoxies and better understood techniques...

RB

[ 01-16-2005, 01:40 PM: Message edited by: RodB ]

[JohnE]

Wow, 30% loss of strength seems like a lot to me.

Does this indicate that metal fasteners are called for in addition to epoxy.

I am particularly concerned about stresses while trailering. In the water, I should have no trouble with high temperatures.

Also when stored covered the temps can go very high. Is a low open roof shelter a better solution than tarping and leaving the underside open? I realize that ventalation is important, but how much is enough.

Perhaps, as mentioned, epoxy is so strong that the loss is not important.

John

[Paul H]

I can't possible see how trailer stresses would be anywhere near 70% of stresses in rough water, so wouldn't worry about it.

Every construction technique, and material is a tradeoff. All boats will eventually fall apart, and all boats need maintenance. I think for a trailered boat, that faces extremes in temps and humidity, you'd be hard pressed to find a construction type that be more conductive to that use then ply encapsulated in epoxy glass.

I don't think plywood on frame would gain much, other then weight and construction complexity, but that's just my opinion.

[JimD]

If I were trying to cover all the bases mentioned so far I would look for an epoxy glued and glassed plywood multichine with battens at the chines with the ply planks fastened to the battens with ring nails or screws. And if I could only find a stitch and glue design I liked I would simply go ahead and add the battens at the plank seams, no problemo, as well as a stem to fasten the planks to at the bow.

And speaking of working with epoxy in hot climates one thing Robb White does is preheat his shop, and therefore the boat in it, to 130 F degrees before epoxying, for better penetration and to allow for outgassing before the epoxy even goes on.

[JimD]

The Welsford 6 Metre Whaler you mentioned in your other thread is just about exactly what I was thinking. Fiberglass the ply planks before they go on the frames.

...using the same simple plywood lapstrake over web frames and stringers structure...
http://www.imagestation.com/picture/sraid154/p1f1bccdd4f9596d835dcaefb9673262c/f5730895.jpg

[RodB]

The multi-chine is more work than a standard panel design. The additional joints still are not a problem and do not need to be mechanically fastened. The joints in a typical stitch and glue or taped seam boat are taped with 5" wide biaxial tape that is very thick and strong. The joint is 10 times stronger than the plywood panels...and from my understanding tests have shown clearly that the actual wood fails long before any joint even comes close to failing.

As far as heat and epoxy in the real world...
My own personal experience... I have a 18 foot (totally sheathed in fiberglass and System III epoxy) skiff in my backyard that now and then, when the sun is at a certain angle, one sheer deck gets direct sun. Since it is unpainted (I am about to complete this boat) , it gets quite hot. approaching the almost too hot to touch mark... It may be a be a little softer when this hot, but not soft enough to dent with the fingernail or anything like that.

This is worst case scenario since it is not painted yet. Now a worse situation would be a dark color finished deck sitting in the sun for hours, which I doubt anyone would let happen with any sense.

Here in Dallas when its 102 degrees the light colored paint I plan to use does not allow the deck surface to get very hot at all. As far as glue joints failing, I cannot imagine any major structural joint in my boat even remotely getting hot enough to fail ...it would have to be put in an oven or something like that and then I have my doubts.

I have noticed some creep in a scarf joint on my rubrail where there is a significant amount of stress... but that seems to diminish as time goes by with complete cure of the epoxy (I repaired it once with a saw cut and application of new epoxy) and once I paint it that will cease to be an issue. I could have avoided that little bit of creep if I had placed the scarf in another spot...

I think it important to note that a common failure noticed by boatbuilders is the "creep" in structures. Creep is a product of elevated temperature over time and if stresses come into play in the structure, the creep will be worse.

Just a few thoughts on epoxy in the heat of Texas.

RB

[ 01-16-2005, 03:50 PM: Message edited by: RodB ]

[Venchka]

Originally posted by JohnE:
...Is a low open roof shelter a better solution than tarping and leaving the underside open? I realize that ventalation is important, but how much is enough.

JohnLow open roof shelter is WAY better. Tarps don't breathe enough or get blown away or trap condensation. Too much ventilation is almost enough. smile.gif

Wayne
In the Swamp. :D