Flattening Plywood

[rick7938]

I found 3 sheets of 2' X2' 5-ply 1/2-inch plywood that is laminated on both sides with a plastic veneer. It was in the scrap bin at the Restore Warehouse for $1/sheet. I want to use it for tablesaw inserts, jigs, etc., but each sheet has a small bow in it from other boards laying on top of them.

I have had a section of railroad track sitting on a sheet that is supported on both ends by boards. The sheet deflects under the weight of the track, but doesn't want to stay straight even after 3 days under the weight.

Any ideas on how to straighten this stuff out? The plastic laminate is only paper-thin, so I don't see that as the problem.

Thanks for any feedback.

 

[WoodWrangler]

http://www.finehomebuilding.com/how-to/tips/flattening-warped-plywood.aspx

 

[rick7938]

That would work except it has the plastic lamination on both sides and won't absorb moisture.

 

[WoodWrangler]

Good point. Poke holes in it? Maybe not.

If it's as steamy out today where you live as it is here in Charlotte, just set it outside. Then, tomorrow it will be plenty soaked and should flatten out nicely.

 

[rick7938]

You might have a good point about the humidity. Maybe I could make a plastic tent and put a boiler of water under it. Of course, the laminate may turn loose in which case I can use your original suggestion.

Thanks.

 

[Gofor]

If it has that tendency to warp, you may not want to use it for critical jigs. Should be okay for inserts if the bow is slight, or for a sacrificial fence that has a flat surface to fasten it to.

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