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type of plywood

Posted: Tue Sep 21, 2010 2:55 am
by fransjoe
what type of plywood do you guys recommend for someone on a really tight budget, or if not I'll have to space out the materiel purchasing. Can I get away with using home construction plywood? maybe Birch or Pine?

Re: type of plywood

Posted: Tue Sep 21, 2010 6:06 am
by jem
Underlayment plywood is a good quality ply. But it typically doesn't come any less than 1/4" [6mm] and is a little heavy. Not a bad choice for a simple hull with taped seams (as opposed to full fiberglass coverage).

Pine can be heavy. Baltic Birch is ok if you can find smaller thickness.

A lot of builders are turning to creating their own flat panels from strips cedar glued. Turns out very light and pleasing to the eye but that requires full fiberglass coverage... which is more expensive than just taped seams.

Some builder have luck with el-cheapo ply from Home Depot or Lowes. But the outer faces are paper thin. I would recommend against using it for taped-seams only. It's a bit too brittle for that.

Unfortunately, the supply for decent quality ply is on the decline which is driving up cost.

Re: type of plywood

Posted: Tue Sep 21, 2010 4:22 pm
by fransjoe
jem wrote:A lot of builders are turning to creating their own flat panels from strips cedar glued. Turns out very light and pleasing to the eye but that requires full fiberglass coverage... which is more expensive than just taped seams.
I wonder if it just goes with regular Carpenter's glue for the strips or do I use the epoxy?

Re: type of plywood

Posted: Tue Sep 21, 2010 4:36 pm
by jem
I'd go with Titebond III which is waterproof. It's commonly available.

Re: type of plywood

Posted: Tue Sep 21, 2010 7:17 pm
by Oldsparkey
The Titebond III is a good one to use when putting the strips together. It is what I used to get everything formed so I knew what it was going to do. Even if you want to do some sanding it will hold everything for you.
After that I ran a bead of epoxy along the seams to make sure they would not move or separate when putting everything together.

:lol: Matt accused me of staring a new trend , I was the one that did the 1st boat that way of the strip , stitch and glue without any frames and just making panels to make the boat. Anyway the 1st one that I know of to be posted on any web site. Folks have been making strip boats for ages , just not this way.

If you are using a band saw to cut the strips make sure you have the widest blade on there that it will take , I used a 1/4 inch blade to cut the redwood strips and the blade would move on me which caused a lot of sanding to get everything the same thickness. Needless to say the strips were quite wavy on the 1/4 inch thickness..... Later I found out that the best thing is a 1/2 inch blade since it will not move on you. To late for me since the panels were together and I emptied the local store of there sandpaper to get all of them the same thickness.

Re: type of plywood

Posted: Tue Sep 21, 2010 8:54 pm
by jem
Some "purists" will curse at the use of waterproof variety because "traditional" wood strip boats didn't need it (translation: it wasn't available way back in the day). Way I see it, it costs the same and it's the same process to use it with the same adhesion results. Why not use something that is waterproof?

Re: type of plywood

Posted: Wed Sep 22, 2010 2:01 am
by fransjoe
Sparky, Redwood? wouldn't that be a little heavy for the boat? I'll check my local lumberyards and see if the can strip a few cedar blocks for me, since I don't have anything but basic tools, to the point that I need to buy clamps and sawhorses, lol. Lost all my cool tools in the move from Va. to Ca. 10 years ago, and really never had any need to buy new ones until now :oops: , so this will be a true "handmade" boat :lol: :shock: :o

Re: type of plywood

Posted: Wed Sep 22, 2010 8:07 am
by Oldsparkey
A pirogue with 144 strips ( each strip was 8 feet) to make it weighed 40 pounds and is 15 1/5 feet in length.

Re: type of plywood

Posted: Wed Sep 22, 2010 2:57 pm
by fransjoe
great idea, I can find redwood a lot easier tha cedar, maybe some redwood and birch strips?

Re: type of plywood

Posted: Wed Sep 22, 2010 7:06 pm
by Oldsparkey
Red Wood will take more of the epoxy then plywood but the more it takes the better it is protected. Anyway the red wood I had required more epoxy to saturate it but it was some that has cured for about 30 years or longer.

Sanding it make sure you wear a mask or some form breathing protection since the dust from it is not really good for you. About the same as cedar which can give you one beauty of a headache when breathing the dust. Actually both of them are considered toxic , might be one reason why bugs don't get in them.