Testing Plywood glue.

[Boomyal]

How long should it take plywood, without exterior glue, to delaminate in a bucket of water?<br /><br />Last year I bought some beautiful 1/2" 7 ply mahogany faced imported plywood. It was very well priced. I have long cut the plywood to shape and soaked it in CPES and rolled epoxy resin on all sides.<br /><br />I'm not too far from being ready to install it but I got to worrying about whether or not it was the real exterior grade stuff. The vendor assured me it was but decided I should test it.<br /><br />I've taken an untreated piece and put in in a bucket full of water. It has now been in there for about 2 or 3 full days and is, so far, not showing any signs of delamination. I just don't know how long it might take if was really interior ply.

 

[kevin500]

Re: Testing Plywood glue.

I am sure someone will correct me if I am wrong.. <br />But try taking it out of the bucket for a half a day, put it back for half a day. If the wood is wet all the time, I would think that it would swell and hold together. By using the wet/dry/wet/dry cycle a few times, it should be harder on the wood than leaving it immersed. The expansion/contraction by using this method should tell you a story about the wood...

 

[Paul Moir]

Re: Testing Plywood glue.

The test I use is a quick boil-dry-boil. Boil a small sample for about an hour , dry it somewhere warm (even bake it in a warm, < 212° oven if in a real hurry) and boil it again. If it doesn't delaminate after that, it won't delaminate on you in the real world.

 

[Boomyal]

Re: Testing Plywood glue.

It's unanimous then. I'll do the soak and dry test. Thanks all.

 

[BillP]

Re: Testing Plywood glue.

You might want to search for boiling time tests. Last I remember reading about testing exterior ply it was continuously boiled 24 hrs...no cycling or drying and was the same test as house siding. <br /><br />Many years ago I bought 5'x 5' sheets of imported ply from WEST Systems for wood/epoxy sheathing a boat. There were several sheets left over and I stored them in the rafters of a shed. A couple yrs later the sheets were all delaminated...and they never got wet or had outside exposure. I figured WEST used interior ply and depended on epoxy to keep it sealed. I wouldn't do it that way again but it shows interior glue is believed to work if you can keep it dry.