Pine Plywood?

[DDcap]

Has anybody tried building a small skiff from pine plywood?

I am thinking of trying it for my first boat because I figure no matter how good wood I get there will be at least 1 problem anyway. It won’t be in the water too much, because between each use we will bring it back on the beach.

What problems will I encounter? How long would it last before it becomes incapable of taking me out?

There won’t be any bends in the design, and I will coat the bottom with fiberglass if that helps.

Sorry I’m new to this.

[gonzo]

It will last quite a long time. If you store it out of the water, that will be several years.

[DDcap]

What if there was no fiberglass bottom?

[PAR]

What kind of plywood are you thinking of using? I don't know of any "pine plywood" generally available, so being more specific about what you're using would be helpful. I also don't know of any small skiff designs that don't have bends in them some place, so what design are you planning on building?

[DDcap]

I should’ve said “based on a skiff” design. I attached a picture of about what I was thinking that I sketched up(using google SketchUp). The design is ugly, although seems simple enough to make and doesnt take too much material.

I would use Southern Yellow Shortleaf Pine BC plywood although I’m undecided on the thickness of it.

Would it be seaworthy without fiberglass, or would I need to put at least fiberglass tape on the joints?

[hoytedow]

There will be problems of warpage and large "bubbles" of raised wood, especially where there are voids.

[PAR]

Douglas fir plywood is a better choice for weight.

In the other thread about your design aspects, I suggested and will again, that you should strongly consider buying a set of plans. I mean no disrespect, but your questions, engineering skills and lack of understanding in regard to the most basic of hydrodynamics, brings one to this logical conclusion.

If a successful outcome and fine little boat is what you're after, then no self designed skiff is going to do, there's just way to much information to absorb, before you're ready for this.

[lewisboats]

Arocco ply is radiata pine (underlayment, waterproof glue, 3 ply with no visible voids and no footballs on one side, a couple on the other). I built my scow partially out of it (bottom and deck). Started checking with only a single thin coat of epoxy on it and no paint (last year). This year it had 2 more coats, 2 coats of primer and 2 coats of paint...no checking like last year. It doesn't live outside...yet, but it will after I finish the after deck/sealed compartment. No comment on anything else.

[tom28571]

There is some pine plywood available locally. Most likely it is loblolly since that is the dominant pine farmed in the South. I have used quite a bit of the 3/8" underlayment pine with waterproof glue for shop walls and overhead as well as underlayment and it has always worked out well. Never used it for a boat though. Cost was about the same as 1/4" luan. Don't think it is available in 1/4" so the boat will be a little heavy but that may not be a problem for you. Still lighter weight than the old nailed up plank skiffs.

[Steve W]

That Arouco ply looks nice, the construction looks much better than any US made plywood ive seen, they sell it at Menards locally and the stuff ive looked at seems to be free of voids. Id sure try it for a project like yours, pine is not resistant to rot,but then neither is BS1088 occume marine ply so it needs to be well painted, a good alkyd enamel will be fine as long as you store it upside down and blocked up off the ground. Of course glassing the outside and sealing the inside with epoxy would be better but of course at much greater cost. It will last a long long time stored properly.
Steve.

[hoytedow]

1/4" thick plywood is very easy to bend and not all that complex to work with. Get some good plans and save yourself from a nightmare.

[pistnbroke]

hang on here ..this is a repeat of another current post on a flat bottomed skiff ...the sketch is identical

[Boat Design Net Moderator]

Originally Posted by pistnbroke

hang on here ..this is a repeat of another current post on a flat bottomed skiff ...the sketch is identical

Yes, the thread where DDcap asked for feedback on his sketch is located here: Flat bottom skiff design

[pistnbroke]

Same answer all you need to know about cheap ply ..fixing it ..and testing glue is on Hannu's Boatyard site !!!!!

[motorbike]

pine ply is pinus radiata, basically its crap. Unless you get the tanalised version then it lasts quite well. Pine is weak but if you use a thick enough sheet ti will be fine.