eterior AC ply

The only caveat to that plywood is that it is made of Baltic Birch. Anyone around here will tell you that it will rot away as you look at it but I know that there are plenty of boats built of it in russia, scandinavia and the like. Maybe the fact that it doesn't get all that warm up there helps to prevent rot...I don't know. I personally am building a small 13 ft sailboat for my son out of it (nothing done yet because of sub-zero weather recently...planning on cutting wood next week though). I will certainly be sealing the surface plies and edge grain and the boat will be dry sailed...probably only a few times a year so I don't anticipate any issues with rot for a while.

my $.02

PS: Menards is a mid-west thing...he probably thinks you are swearing at him

 

Sorry about the localisms

 

Experience shows that birch plywood is a lot more rot resistant than birch timber. Nobody seems to know why, but different theories have been presented. Traditional know-how in Finland said that birch should be kept off boats and used for furniture, but plywood has been used succesfully for planking boats.

One example:


I have started to build PAR's schooner using birch plywood. I will come back in ten years with some first hand info

 

Thank for all the information I was pretty sure it would work out ok but felt it would be better to ask before I spent money on a disaster. I never thought about underlay though and as far as getting the stuff I have sort of a running account with Fairhaven Lumber seeing as i'm there getting something or other 2-3 times a week. Pic will be coming as soon as the weather breaks so that i can start.

 

TKK,

Good luck with that little schooner..I don't think you could have chosen many better ones to build than that gaff-rigger...the rudder looks very,very robust in its design.That boat looks like it could go just about anywhere in my IMHO...keep us posted please..

 

Yes...the weather...projections for the next 10 days are for highs a bit above freezing and lows a bit more below freezing so I should be able to start cutting wood soon. I'll rip the sheets then bring them inside to lay out the panels then back out to cut. I could probably stitch the boat together but then I'll have to get different epoxy and/or wait until I have decent temps to do anything more on the hull. I can start on other stuff though. I should have already made the rudder and daggerboard but I work too much and I am lazy most times when I get home in the morning.

 

Just looked at this same stuff at Lowes, agree with the above post. Would like to find some of the 5equal ply that was talked about locally.

 

Souljour, I was just setting masonite boards on my concrete floor to start lofting. It is still really early phases.

I had a go on casting the ballast earlier () because I spotted a cheap lot of scrap lead and I wanted to do it before winter. Need to redo it when the ground is thawn.

Concerning weather, we had -28C last week , now only -4C. But my workshop has a steady +21C

 

Ahh the wonders of heat, I have a nice little pot belly stove that keeps things nice and toasty when I'm working on something or other not to mention it's a nice way do dispose of that inevitable build up of scrap. Concerning the underlayment in MA I've never seen that 5 ply talked about earlier although if you do find some let me know where I may want to look into it.

 

The stuff I have is called PlyFloor and has little green x's printed on it...to show folks who don't know how to nail...where to nail. Ruins the chance for a bright finish but it isn't the most attractive wood to start with (just plain white) so paint it is. You might try actual lumber yards for contractors rather than the big box stores like Home Depot or Lowes. Lots of times you can only find it in 5'x4' sheets. My local store (Menard's) only started carrying it within the last year or so.

 

Please do not use any plywood made in China. You will have no idea who, what, where, and why what is in it.

 

tkk

the heat load when glueing the veneers to become ply, neutralizes the sugar content in birch wood, thats it.

Regards
Richard

 

In protecting the ply from the elements, it sounds like the only portions of the wood that are epoxied are the edges and voids. Is this correct or do you try to encapsulate the plywood at all.

I ask because most everything I've built, I go the full course with glass sheathing and encapsulation. There are times when I'd like to try an idea without the expense of a full bore glass and epoxy scheme. Upping the ply thickness and foregoing most of the glass makes for a great reduction in prototyping a design.

 

The idea that a void is enough to make plywood unacceptable is not really valid. Wood is more air than solid. It is made of a bunch of little tubes glued together to different extent depending on the species. That means that all wood is open at the ends, not just plywood with voids.

 

Gonzo,

Maybe I was unclear. You mention glass taping the seams, but do you also epoxy coat the plywood or only epoxy the taped joints? Do you rely on the paint to seal the plywood?