Okoume marine plywood

[Kristen Stevens]

I need some advice as to how to apply okoume plywood. I recently bought a 1938 50 ft wooden Ketch that is in need of repair. How easy is this to work with? What type of apoxy is the best to use? How many layers? HELP!!! Any advice is greatly appreciated! Thank you!

[Mr. Know It All]

You have a 50' wooden ketch from 1938? You are definately going to need to hire someone to help you. If you are lucky they will let you watch or assist. I once had a mechanic tell me $25 an hour or $40 an hour if I wanted to watch. :D Good thing you live in Boston. Should be a few people around to give you better advise than me. Sounds like an interesting project. Welcome to the Forum Kristen.

[imported_Steven Bauer]

Wow, a 50' ketch from 1938! Let's have some more background info. Like the designer and the builder. What shape is she in? What do you plan to do with the Okoume? Different kinds of epoxy are best for different things - what are you doing with it. And most important - do you have pictures to share with us?
Oh yeah, welcome to the forum.
Steven

[Steve Lansdowne]

Originally posted by Steve Lansdowne:
I don't believe that such plywood was in existence when your ship was built, in fact I doubt that any type of plywood even existed at that time. Thus, you sound as if you're going to put plywood where it didn't originally exist. This may nor may not be a good idea. Marine plywood is the type to use on a boat, as it is certified to not have air pockets caused by spaces where the plys had knots that fell out, but that you can't see as they are not in the outside layers. Your question is rather vague and thus I doubt you'll get many intelligent replies unless you are more specific. If you have access to a digital camera and can post pictures along with more specifics, you'll likely get more applicable responses.

Popular brands of epoxy are West, System 3, MAS, and Raka. Each has its fans. The first two brands, and likely the others, have booklets that describe the use of their products. Carefully reading these is essential for safety. System 3 has a starter pack you can purchase for $15 that will allow you to learn about and experiment with their product. Try the web sites of these companies to learn more about their products.

I suggest you use the search function on the Forum to look for previous postings that address epoxy and various other topics of general interest to you, as many topics have been debated nearly endlessly in times past and those who posted then may not be eager to say it all again.

Welcome to the Forum, and keep those questions coming.

[imported_Sean]

Kristen;

I recently renovated the cockpit on my 55 year old sloop with maranti plywood and epoxy. I made some templates out of masonite to get the fits as close as possible. then I laid the plywood. Saturated in epoxy (epiglass). A layer of very light cloth then epoxy fillets around the seams and painted with a no-skid paint.

It was alot of work but I am well pleased with the results.
Are you planning on a new deck ?

Good luck.

[Tomcat]

You could also request the WEST booklet on using epoxy for repairing old boats. They try to draw a line along where it will help, and where it will hurt. Issues around epoxy are simmilar to ply, since they involve dimensionaly stable materials being used where dimensions aren't stable, and these materials are often used together.

[Kristen Stevens]

What is the WEST booklet? We are real novices at this boat repair business and need clarification on a lot of terms and jargon....

[Steve Lansdowne]

West System epoxy. Go to www.westsystem.com (http://www.westsystem.com) and find out more about it. They publish literature about use of their product. They are a very well known and respected epoxy maker. System 3, similarly. They have a web site also. I suggest you review the ads in a copy of WoodenBoat.

[ 09-06-2002, 10:37 PM: Message edited by: Steve Lansdowne ]

[CyberRebel]

Kristen,
I'm afraid that if you have never heard of WEST System epoxy, you are in waaayyyy over your head. Methinks it's time to do some SERIOUS study before attempting ANY repairs to this boat. There are professionals here that would likely run scared from a 65 year old 50' boat, and they know how to fix it! I've never attempted anything of this magnitude and I'm not an expert, but from what I've learned here on this forum I'd say, if you don't have the money to hire a professional then you probably can't afford to do this yourself either. Good luck and best wishes, but please don't attempt something you're not ready for. :(

[Tar Devil]

Is this serious?

Later,

Phil

[Kristen Stevens]

What do you mean...is this serious?

[Mac_Muz]

Kristen Stevens, I hope you have more brains than money, and that you have plenty of money too! Your gonna need both!

I would get this boat surveyed in a heart beat, and pray to what ever gods you pray to, that you bought a fairly sound boat.

Spend a year learning things and then begin work.

Some things are historical, others are safety related... like what your gonna do if you don't get the boat surveyed, cut a few corners and the keel goes to Davy Jone's locker in a 15 knot breeze.

If you really don't know whats under all the pretty wood, and how that works, your are in way over yer head..

A boat is a hole in the water into which you pour money, and if you don't pour in enough it may well take you with it.

I work on lake boats and it is not uncommon to pour 30,000.00 dollars into a restoration for a 28 foot by 14 lake boat these days... There are those that consider that cheap.

It will take a grand just to protect this boat from the dry dock ravages of winter....

You never did say what the ply wood was for... And in '38' there was no such thing as plywood.

A '39' 21 foot Chris Craft just left our shop, and the guy spent only a little on it(15 grand)... A few side planks and a go over job with out fairing the hull, a engine tune up and scraping and painting the bottom...... He knew it was a short cut, and he does not have any real weight, and the boat truly needs a new bottom complete as the inner planks are weak at best...... He can get away with this as there is no keel.... if there was a few tons of iron under that bottom it would go down in a heart beat.....

If I were you I would stay here, and do lots of reading, but keep in mind these guys work on smaller craft than yours for the most part... Mac

[Bruce Taylor]

Plywood was invented in the third millenium BCE, (by the Egyptians). In 1865, John Mayo of New York developed the idea of cross-laminating veneers to make large panels. Ply become widely available after 1934, when appropriate waterproof glues came into use.

God, I love Google.

[ 09-09-2002, 03:03 PM: Message edited by: Bruce Taylor ]

[Kristen Stevens]

Thank you for the google research. I realize the amount of work this is going to take and we have done a survey of the boat. However, we have heard varying opinions as to what to do with the hull - re-plank ($$$$), fiberglass or marine plywood...I know the $ involved, I know about the time. I just wanted some concrete advice on how to apply the marine plywood - how diificult is it? How expensive? My boyfriend is a woodworker and knows how to use the tools, epoxy etc... I am merely performing research duties on his behalf.

[Mr. Know It All]

Ahhhh.....I see said the blind man. :D
OK Kristen, what part of the boat needs attention? Are you replanking the hull? Replacing the decking? What type of construction method and what was the original type of wood used? We will be glad to help with advise if you can give us a little more information. Can you post pictures? You know what they say...." a picture is worth a thousand words".
Peace---> Kevin in Ohio

[jeff pierce]

Ahhh, its beginning to become clear. You didn't get much of a specific answer thusfar because you weren't real clear on what you were contemplating doing with the plywood. I take it that you have decided that the planking, for whatever reason, is suspect.

You are considering: (a) Replanking the entire hull, (b) Encasing the entire hull in fiberglass or (c) adding a plywood skin over the entire hull. Did I get that right?

Assuming I have got that right, I would forget about (b) and (c). In my inexpert opinion, neither is a viable option. Your traditionally planked hull moves...alot. The plywood or glass will not stand up to this motion, will trap moisture and promote rot and probably cause a few more problems I don't even know about. As much as you may not want to hear this, if you are going to do the job, you are going to have to do it right.

Now, are you sure it really needs a complete planking replacement? Fill us in on more of the details. Pictures would be nice.

Good luck and keep us posted.

[Tar Devil]

Kristen, sorry to sound flippant, but at least four respondents asked what you planned to do with the okoume ply, and we still don't have a clue. I would only assume, from your last entry that perhaps you you are considering ply in place of existing planking? If so, what kind of planking? And fiberglass?? ...over carvel planking?

The longer I hang around this forum, the more I learn... and the more I learn, the more I scale down my wooden boat ambitions. Not being a defeatest, just being realistic.

NOW... what'cha gonna do with that plywood??

Later,

Phil

PS... Re-reading this topic, I feel compelled to apologize for my response. This is a place of learning, fun and fellowship; so smack my face for doing anything to make you feel unwelcome.

So, begging your forgiveness...

Later,

Phil

[ 09-09-2002, 06:05 PM: Message edited by: Phillip ]

[Meerkat]

Phillip said:

This is a place of learning, fun and fellowship We do "hership" pretty well too ;)

[JimD]

According to WB isssue #163 "Okoume(Aucoumea klaineana) is also known as 'gaboon mahogany, or simply 'gaboon',...comes from the forests in a restricted area of Africa - Gabon, Rio Muni, and Congo-Brazzavile....has no decay resistance...As early as 1913 okoume was being exported in larger quantities than African mahogany..."

As for how to apply it, well like with most plywood, it usually gets applied in sheets and you can even apply it in smaller peices by cutting up the sheets...

[Mr. Know It All]

Wouldn't Marine grade Douglas Fir be better (more rot resistant) and cheaper for a painted hull?

[JimD]

Originally posted by Mr. Know It All:
Wouldn't Marine grade Douglas Fir be better (more rot resistant) and cheaper for a painted hull?I agree, Mr Know it All. Okoume looks nice for brightwork, great for natural finish kayaks, etc but somehow it has become synonymous with the best plywood for boats for any purpose. Plenty of other good marine ply out there, me thinks

[Mac_Muz]

My first hearing of the use of plywood was from WW-2 in PT boats.

I know what it is to be a "Traditionalist". So it is my belief that even if 20 tons of plywood was delivered free to a boat builder in 38' that it would be used as templates and not boats itself..

It takes something like the Navy to have a want for cheap and fast...... To get any boat designer to want to figure out how to build in a new material.....

Other non boat related items in the past were not utilized for about the same reasons... The term was "New Fangled" and was ment as not tried and true, therefore not trusted.

I still can't make heads and tails of the requested question.

Our shop uses West Systems Epoxie. There are many fillers for different strenghs and thickness of epoxie.

In general and I hate doing that here... First you cut the ply to shape and fit it, then coat the part, and the place where it fits with well mixed epoxie with no filler.

Then you add filler to the mixed epoxie, and recoat the new ply. Sometimes you add more to the place. The idea here is that the straight epoxie penatrates the wood fiber, the the filler acts as a voids filler. You want no voids for water to seep into.

At that point the new part is clamped with medium pressure and adjust and allowed to take a set.

When clamped correctly filler mixed epoxie squeezes out from the joints some, and not all the epoxie is lost. It is very possible to clamp too tight! That cause a weak joint.

Once this sets there usually is no longer any movement in the part, and if that part is supposed to work (move) and it won't this may cause a failure at the new part, or a working part next to it.

This is why (WE HERE) are attempting to see what parts and where, and what the rest of the hull is.....

Many hulls move with water pressure, and they were designed to move, and work in a way that allows the hull to flex. If you add a non moving part it adds up to a bigger problem.

To make an anology I hope that can be understood, I am sure you can imagine a small piece of gravel caught between your toes in sandels. As you walk the pebble is a solid that has no give and take, but your toes do. As you continue to ignor the pebble, you flesh begins to suffer damage for it.

At first the damage is slight, but as wear becomes more and more a blister comes, and then that breaks and leaves raw flesh, and finally the hull is breeched and you bleed..... Does this work?

At first I took Kristen for a guy... Sorry... But still I have one more caution for the "wood worker" It also is very possible to fit a plank too tight... A wood framer might make a better boat builder than a cabinet maker, as too tight of a fit once swelled can damage fasteners, and open seams far from the place where a new piece was fit.

Some things we might like to know, are what wood(s) is the boat made from? the frame is??? the planks are???

What caulking was used?

What is the hull type Clinker, Carvel?

What fasteners type is most used, and what metal(s) are these... Silicon Bronze, monell, Galvanized steel?

How many planks are bad, and where are these planks? Above or below water and or both?

As has been said a few pics are most welcome.... Mac

[WWheeler]

Hey guys, sounds like we've scared Kristen off. She sounds way more committed than you were willing to give her credit for.

Kristen, please respond. I'd like to know more about your project. The suspense is killing me.

PS Sam Devlin (Devlin Boats) recommended okoume over Doug fir. He claims that domestic marine plywood is full of voids that leads to rot.

[ 09-11-2002, 09:08 AM: Message edited by: WWheeler ]

[Garrett Lowell]

Typical. Someone comes on here and asks for advice and help, and aside from Billy Bones and a few others, receives scorn and ridicule. Why even post something like "is this serious?", or "hire someone to help you"? I recall a lesson from second grade: if you don't have anything nice to say, don't say anything. It mmay not apply all the time, but certainly it does in this case.
Kristen, good luck.

[Kristen Stevens]

Thank you Garrett and for those of you who gave sound advice. We've decided to go the old school, expensive route and re-plank 'Stormsvala' It will take longer, however, it seems to be the safest most authentic way of restoring our new home. So, any advice on re-planking the hull of a 1938 Ketch?

[G. Schollmeier]

Kristen, start a new thread, use re-planking 1938 Ketch as bait. Many here ignore posts that use the word plywood. They will want many details and pictures. Good luck. smile.gif
Gary

[JimD]

Kristen, plywood is a great building material for many purposes on a boat, but there's nothing prettier afloat than a planked and caulked old boat. Like some others on this forum I'm one of those often more wise guy than wise (ok, I'm dun grovelling smile.gif ). You might find many uses for marine ply such as okoume. It's a really nice lookin' wood with an epoxy finish.
Sounds like you have a boat many including me would dream of owning and sailing.
jimd

[Mr. Know It All]

Garret and Kristen.......I ment neither scorn nor ridicule with my first reply. Kristen seemed to know very little about her boat and didn't make us aware that she had someone helping her already. I thought under those circumstances " hiring Help" was a good idea.I suggested what "I" would do in that situation. I even went so far as to e-mail Kristen and offer to help her post a picture here and apolagise for some of the other coments here. I know very little about sailboats and really couldn't offer much good advise but still wanted to help. My intentions were good. Her post sat here all evening from about 4:30pm until I replyed after 9pm. I was thinking any reply might bump it to the top where someone who could help might see it.I also welcomed her to the forum. Just wanted to make that clear.
Peace----> Kevin in Ohio

[Tar Devil]

Why even post something like "is this serious?", Exactly... which is why I apologized.

I WILL admit when I'm wrong.

Later,

Phil

PS. And I disagree with your "typical" remark. With rare exceptions (and in this case, yours truly included), this forum is quite receptive.

[ 09-12-2002, 04:00 PM: Message edited by: Phillip ]

[Garrett Lowell]

I agree, Phillip, my "typical" remark was unwarranted.