Preserving interior plywood

[odfrank]

I just aquired a few sheets of interior plywood used on large packing crates. Is there something I could soak cut pieces in to make it moisture proof? Or would the soaking process warp it? Some already got wet and look as if it is very sensitive to moisture. The local lumber shupply sales man said interior and exterior ply glues are now all the same, I don't believe it. Any comments?

[tecumseh]

oliver sezs:
Some already got wet and look as if it is very sensitive to moisture.

tecumseh ask:
does this mean the plys seperated or that the sheet warped?

off the cuff I would think any sort of sealant would be adequate.

[BULLSEYE BILL]

I haven't seen boiling in paraffin / rosin warp anything yet.

[peggjam]

Any type of good sealant should work. Cut a piece of scrap and soak it in some sealant and see if it works. Paraffin/rosin would be a good choice too.

[Dave W]

Exterior grade plywood will show black lines between the layers.

Interior grade glue is NOT black. Interior grade plywood will delaminate (come apart) if it gets wet. There is no way (that I'm aware of) to make interior plywood last outside. Most ext. plywood and some marine grades delaminate quickly also.

Plywood of any kind, is a poor choice for beehive woodenware. I know, it's cheap, and sometimes free, but it is still a poor choice.

Plywood makes great cabinets, if kept dry. smile.gif

[Mike Gillmore]

I made some boxes last year from shipping crate plywood too. Some of them held up ok, but several bubbled up badly on the exterior ply. They cost me nothing but a little time and paint, but they will probably not last long. Most of them I'll be using as empty boxes above the brood boxes for feeding. I even used putty and painted on the cut edges to try to prevent moisture from getting inside. They are just a quick fix and short term fill-in box.

[Sundance]

Dave hit it on the head. Regardless of
how well you treat the wood, the glue
will fail.

[tecumseh]

mike gilmore sezs:
I made some boxes last year from shipping crate plywood too.

tecumseh replies:
I salvage a bit of this type of mateial also. Most of the time (at least here) the sheets are marked 'blows' .... which in the plywood making business means that some of the glue did not hold and 'bubbles' appear between the plys.

dave w sezs:
Exterior grade plywood will show black lines between the layers.

tecumseh replies:
now that is an interesting bit of info... thank ya' dave.