Plywood glue?

[Boomyal]

I have two half sheets of 3/4" plywood. I want to replace one of the rectangular, vinyl covered seat bases on my Beachcraft. My plan is to elevate the seat by 1 1/2".

There are no markings on this plywood. Anyone know of any clues that would tell me whether the plywood is exterior grade, with corresponding waterproof glue? It is 5 ply wood.

I would hate to go to the effort only to find that the glue was not waterproof. I do plan on soaking all surfaces, screw holes and end grains with diluted epoxy but I think that would be a waste of resources if the glue was for interior use.

 

[tashasdaddy]

Re: Plywood glue?

does it have any paint stipes on the ends, that indicates what it is. Home Depot and Lowes initiated that so the cashiers, could tell what kind it was. and the industry followed. 5 black strips is exterior 3/4.

 

[CalicoKid]

Re: Plywood glue?

You could cut off a scrap and soak it in hot water for a week.

 

[Boomyal]

Re: Plywood glue?

does it have any paint stipes on the ends, that indicates what it is. Home Depot and Lowes initiated that so the cashiers, could tell what kind it was. and the industry followed. 5 black strips is exterior 3/4.

Hmmmm? I dunno. I'll check but this wood may be older than Home Depot or Lowes. It's virtually virgin wood but very brown/orange ish. I had a similar aged piece, in 1/2 inch, that I used to replace a rotted seat cushion board. That stuff was so hard that 1/2 of the monel Arrow staples I used on it just turned into big M's when I drove them in.

I suppose I could try Calico's suggestion.

 

[longshot_kh]

Re: Plywood glue?

Tashasdaddy is right on the paint markings. (I worked in a plywood mill for 10 years) another way to tell exterior plywood is the glue if it is a red/dark brown between the layers it is exterior glue. THat being said exterior rated plywood is just that, barn siding. That doesn't make it marine plywood. Soaking it in epoxy will definitely help but marine plywood has an entirely different grade standard (core voids, cover sheet cracks, and holes in the covers) In a boat I would use only marine plywood even on the seats. My opinion of course but the glue color will tell you the story if they used exterior resin in the mix (ours was polymer resin, dried blood, flour, and caustic acid) The red resin and brown blood was the tell.

Hope it helps
LS

 

[Boomyal]

Re: Plywood glue?

Checked all my 3/4 ply out. There are no colors of any sort on any of the original edges. Also could not detect any glue color. I decided to do calicos suggestion and cut off some pieces and soak them in water. Time will tell but I don't think it was a very good sign when I cut off a 3/4 end to a 16" wide sheet and it immediately fell apart in two pieces. I also cut off a small triangular corner on another piece and it also came off in pieces.

I'll let it soak over night anyway. If the remaining laminates do not fall apart, I guess it must have exterior glue that simply did not make it evenly, on all plys, out to the edge of the board.

 

[Coors]

Re: Plywood glue?

Boom, exactly how old is your ply?
Older than us?

 

[rheagler]

Re: Plywood glue?

Not to sound like the voice of doom but if it fell apart when you cut it, chances are it isn't worth using. In the big scheme of things good quality plywood isn't that expensive, chances are you could buy just 1/2 a sheet if that is all you need. Most plywood is manufactured these days using exterior glue, it isn't cost effective for plywood mills to switch between interior/exterior glues. Just my opinion.

 

[WAVENBYE2]

Re: Plywood glue?

Time will tell but I don't think it was a very good sign when I cut off a 3/4 end to a 16" wide sheet and it immediately fell apart in two pieces. I also cut off a small triangular corner on another piece and it also came off in pieces.

This would be my first clue !! Yikes Boomyal, I think It's time for new wood. Why go through all the trouble just to have to do it all again with new wood>>>Pat

 

[Tail_Gunner]

Re: Plywood glue?

Boom, exactly how old is your ply?
Older than us?

Of course, what the H@# were you thinking anyway's...........

 

[Boomyal]

Re: Plywood glue?

This would be my first clue !! Yikes Boomyal, I think It's time for new wood. Why go through all the trouble just to have to do it all again with new wood>>>Pat

Hey, you save this stuff just in case you might need it someday. I have a whole shed full of it so unless I can prove it is not suitable for epoxy impregnated seat base material, I want to use it. You ought to see the garbage that the original bases were made of. Knots, voids and all. And they are still servicable, especially if they received treatment now.

The issue is that I want to remake one of them with an inch and a half higher base.

I did have to do some miracle salvage work on the seat cushion boards. Many of the screws that held the hinges for the seat back and cushions had just rotted out. I did not want to remove all of the old upholstery, make new boards and re-install the old worn out vinyl. I pulled the staples on the hinge ends of the seat boards, imregnated the boards with CPES, put a piece of duct tape, under the screw holes, between the seat foam and the boards and kept pouring in epoxy resin til they would take no more. That epoxy just oozed into the plys around the holes and eventually filled them up. I redrilled the holes, remounted the hinges then restapled the cushion upholstery. Budda Bing. They are now sounds as a rock.

My soaking plywood samples are going on two+ hours now and have not come apart. I will wait til the morning and if they are still together, I will figure the plywood is suitable for the new elevated seat base frame.

 

[WAVENBYE2]

Re: Plywood glue?

You always give me such good advice I was just wondering!! Press on Buddy

 

[Boomyal]

Re: Plywood glue?

It's been 14 hours of soaking for my cut end plywood samples and there is no sign of any delamination or seperation of the remaining plys that did not fall apart when I cut the end samples off.

I will leave them to soak for 48 hours, but to date it looks like I am good to go with my hoarded ply.

 

[Chris1956]

Re: Plywood glue?

I had thought that all plywood manufactured recently used waterproof glue. such that even "interior" plywood still had waterproof glue.

 

[Tail_Gunner]

Re: Plywood glue?

It's been 14 hours of soaking for my cut end plywood samples and there is no sign of any delamination or seperation of the remaining plys that did not fall apart when I cut the end samples off.

I will leave them to soak for 48 hours, but to date it looks like I am good to go with my hoarded ply.

Better make sure she's pretty tight cause when i hose you with MY Roster Tail.......

Ahh Ya might want to add a bilge pump or two.........

Comes highly recommended from no other than I-Boat's...........

 

[Boomyal]

Re: Plywood glue?

I had thought that all plywood manufactured recently used waterproof glue. such that even "interior" plywood still had waterproof glue.

May be, I dunno. But what would be the difference then and what would all the old grade letters mean.? I don't know what they all were but some were meant to denote exterior grade (glue type I assume) vs interior grade.

 

[Boomyal]

Re: Plywood glue?

Better make sure she's pretty tight cause when i hose you with MY Roster TailAhh Ya might want to add a bilge pump or two.........

The only reason I would need a bilge pump is for the spray I'll take over the bow while leaving you in the ???dust! As for the the integrity of the elevated seat base plywood, the only reason I'm even doing it is so that I can sit up high enough to see your sad countenance over the back of my stern.

 

[Tail_Gunner]

Re: Plywood glue?

The only reason I would need a bilge pump is for the spray I'll take over the bow while leaving you in the ???dust! As for the the integrity of the elevated seat base plywood, the only reason I'm even doing it is so that I can sit up high enough to see your sad countenance over the back of my stern.

............

 

[Coors]

Re: Plywood glue?

Hey Boom, maybe it is a termite problem.
Just a thought...