Birch Plywood in boatbuilding

[Vulkyn]

Reviving an old thread, the information here was great ! The only current wood i can afford is Birch (Finnish) plywood.

I have asked the supplier to have some samples ready so i can do a boil test, the local epoxy is 5 times cheaper than west system which means i can afford to encapsulate the wood properly.

Ill do more tests

[liki]

You can find all the information about Finnish plywoods here:
http://www.metsateollisuus.fi/Infoko...ishPlywood.pdf

[Vulkyn]

Fantastic link liki thanks, doesnt mention any marine application but i sort of gathered that.
I guess proper wetting / coating is a key to use bitch plywood.

Cheers !

[science abuse]

Very informative thread, I wish I'd seen it before mosting mine.

I can' yet speak for submersion, but I've been using Birch ply for the decking of my "rowboat" for over a year now. it has certainly gotten wet, though it hasn't seen immersion. It's coated only with a few layers of spray-on polyuerethane, with West Systems epoxy run around the edges, and it still looks brand new.

Iv'e also got a table in th eback yard made withthe same stuff, though amore halfassed aplication of poly. After a full summer and winter exposed to the elements, it's blackening a bit around the edges but is still as structurally sound as it what when i built it. That's not to say it was ever sound enough to be make a hull or keelson, but it has weathered well.

[pistnbroke]

when was the last time you boiled your boat ?
Will it be in the water 24/7 ...?
How long do you want the boat to last ?
Have a look at Hanuu's Boatyard ..end of the article ..he tests all the glues etc ..some of his boats he does not even paint ....

[Steve W]

We have altic birch ply in the local big box lumberyard (menards) and its very nice stuff,ill be interested to see the result of your boil test. My son made up some cradles which are screwed to the side of his house where we have stored our 2 stitch and glue kayaks for the last 8 years,the cradles are unsealed with the edges totally exposed and so far zero delam or rot. The kayaks are okume btw are dynel sheathed and sprayed with nason fulthane car paint and are still as shiny as new.
Steve

[PAR]

Birch is an awfully heavy material and not especially rot resistant, so I'd be inclined to use it only as a decorative veneer. On the other hand, if this is all you can get . . .

[Dirteater]

my two cents,

My father built birch bark canoes in the Yukon in his youth.
"fabulous" he would say. so I can't help but
think it is the bark. I don't ever recall
the birchwood itself being used.
however, it wasn't necessarily required either.

as PAR mentions, weight is a factor.
and "science abuse" raises some flags. (coverage)
I'm not convinced Birch is a good choice yet?

However "this thread" has got me wondering
of how? one might work birch bark into a design.
could be a nice touch?
(I apologize for the tangent).

DE

[rberrey]

If the baltic birch or finn form, is made for the concret form industry it will more than likely have been made with water profe glue. I have some 6" strips of 3/4 baltic birch in my back yard that has been exposed to weather for over 8 yrs that are are fine , no delam. That being said I would not use baltic birch from a big box store or cabnet shop unless it could be verified it was produced with water profe glue. I have used bundles of 3/4 baltic birch, it is by far the finest form ply produced as a whole , it is also the hardest and stiffest. You will have a tough time bending baltic birch , but I would use it without hesitation on bulkheads and other parts where weight or bending is not an issue. I read a post where someone used baltic birch form ply on his keel and had no rot after a long number of years. Form ply maybe an option and maybe some price saveings , but it will be avalible for the most part from 1/2, 5/8, 3/4, also the it may have been pre coated in a form releace agent. Bottem line if buying baltic birch for a boat know what your buying. rick

[pistnbroke]

maybe I misread this post but I did not see any indication of he size of the boat .....could be a one sheet 1/8 ply stitch and glue or much much bigger ????