inexpensive plywood

ya I was never a big picture taker myself, didn't even own a camera before a few years ago so everything I show is fairly recent, I keep meaning to get out and spend a week or so traveling around to all the stuff I build thats worthy of the trip and get some pictures, might even muster some biz cause the high end glass definitely has a life span. Anyway thanks for indulging me. Hope all is well

Cheers
B

 

par, thank's for your response. I am out here to get advice, going to be building soon. Just thought your back in forth disrespecting responses with michael were lame. If that happened on my job site the boxing gloves would be brought out. Any ways i like what you both have to say, mabee, you guys can keep it to private responses if your going to keep going on and on with each other. For example, like little mickey & par the famous. comment's like this is poor at best.
p.s. I hope you don't take this againt me, i too have something to say, and all i want to do is learn
thanks eric raguckis

 

how difficult would it be to make plywood?

 

I've been there and done this Wardd, it's fairly easy, but not as rewarding as you might think. I made some custom length sheets for lapstrake planking years ago. I was able to get 14' fitches of Douglas fir, so each sheet was just short of this when glued up. Edge matching, veneer alignment, glue spreading and maintaining pressure during the cure were the big issues. I'd never do it again, unless I was molding to shape. Scarfing or using a Payson butt joint is just too easy to warrant making over size panels.

No problem Eric, Michael has refused to stand up for his own comments, words and theories, so I and others have picked on him. It's not that he doesn't offer assistance, he does, sometimes quite well, but he also sticks his foot in his mouth a lot and it's hard not to stare and point when he does.

 

Agreed. For such a small boat the extra cost of marine grade is well worth it. Or you can buy the cheap crap and wear a grocery bag on your head.

 

I too have tried too make plywood, not very easy unless you have a press specifically set up for that not including spreading the glue over a surface that big before glue sets up, it very hard to get constant sheets. par is on it

 

So, Hoyt, you'd use $1,200 dollars of plywood for a $500 skiff? Everyone knows how I feel about construction grades of material, especially plywood, but an uncle John's or Lumberyard or other cheap, no nonsense boat, is difficult to justify the lumber bill rivaling the engine purchase. My Digger design needs 11 sheets of 1/2" plywood. That's $1,250 in BS-1088, $715 in BS-6566 or less then half of this if ACX or double layers of 1/4".

Folks looking to build a Lumberyard or a Digger aren't looking for a silk purse, just a wholesome, lets get out there boat. They'll buy a $500 engine, stick it on their $500 boat, painted with $25 a gallon porch and deck enamel and have fun. I don't think quadrupling the plywood bill on a boat like this will increase the fun aspect.

 

You build them better than I do PAR, and I wouldn't go over $150.00 for plywood for a 16' boat, because I build them light and cheap. I'm pretty much out of it now anyway.

 

You and I are in agreement, though some projects just don't deserve Okoume. All projects can benefit from Okoume, but not all can justify it's cost, IMO.

 

A lot of interesting thouroughly justified theorys here made by the ones who know ....thanks, that 2+2 equals four can not be denied and needs no justification .....

 

How should someone test plywood they might want to use for boatbuilding?

The other day at Home Depot, they had a pile of 3/4" A-C plywood from Chile, a special buy, for $25 a sheet. It was 7 ply, all plys of equal thickness, no overlaps, very few voids, looking at the 8' side of a 30 sheet pile there were maybe 15 to 20 - 1/4" and smaller voids. No plugs on the A side, very few on the C side and every sheet absolutely flat.

They had it marked as 'cabinet' plywood and their generic description poster of terms said 'cabinet' meant interior glue or interior use. I wonder why would anyone would bother using interior glue to begin with and also wonder if they didn't know what glue was used and just called it that to cover their butts.

What would be a good way to quickly (or not so quickly) test the plywood for marine use? I would assume the hull would be assembled, and after the outside glassed the inside (which would be protected from weather and kept "dry") would be treated with a preservative such as borates and be readily accessible for retreating.

 

cut off a piece and boil it for an hour to see if it delaminates. Or if you can then pull the plys apart.

 

Actually, you need the wet/dry cycling to get the panel to delaminate. This causes the wood to swell and contract against it's glue lines.

The color of the glue lines is a good indicator and with all those void, the panel can't be reliably bent without some internal failures.

 

Sam, under no circumstance should you use any plywood that is not at least sold as exterior bonded, if HD are saying its interior i wouldnt even bother testing it.I have seen way too much plywood where the glue has just disapeared leaving perfectly good veneers with no rot. I agree with those who say that some projects dont demand BS1088 but dont agree with using the likes of CDX for example. As with most things,the middle of the road approach makes the most sense,the best ply you can buy for a reasonable price,not necessarily the cheapest stuff you can buy. I have seen some quite nice radiata pine ply in the local Menards big box for a very reasonably price called Arroucco ply that i wouldnt mind trying on a small boat project.

Steve.

 

As Par has said,the color is good indicator,if it has a clear glueline its probably interior, dark is likely exterior. Another thing ive found is that an interior glueline has a completly different smell. You of course need to test to verify. I dont actually think you do need to cycle from wet to dry, i have seen totally delamed ply with no rot that was used as a replacement for balsa core under hardware in production boats,where water had gotten down the bolt holes and rotted the balsa, the ply was saturated,the glue completly gone but no rot of the veneers, i am pretty sure that once the ply got wet it never dried out.This was not an isolated incident, ive seen it many times when recoring C&C decks,it seems they used some nice looking ply with the wrong glueline.

Steve