Proofgrade Warp

[userk999]

I know that warped proofgrade plywood is not a new topic, but does anyone else think that the problem has gotten worse with recent proofgrade purchases?

With my original package of plywood I just stored it on a shelf and I never noticed warping. Recently, I have taken to storing it on a sturdy, flat bench with a 3/4" piece of plywood and a 40 pound weight on top of the pile. And every piece has significant warpage. I don’t know what I would do without Eljefe4’s crumb tray hold down pins.

Is it possible that my new method of storage is making things worse?
Does anyone have a reliable method of storing PG plywood?

Thanks
K

[DaveL]

Much of what I ordered was warped on arrival so I used the same method as you to see if I could flatten them out. I have not gotten around to using them yet but was hoping that would work.

[Jules]

No, but I haven’t ordered wood lately. (The season can have an impact. Rainy springs tend to up the humidity level, and the warpage.)

Flat storage is best. Weights are definitely okay if you have them on top, but it can still take a week or more for the material to acclimate and flatten back out a little.

[jbv]

@userk999

Does anyone have a reliable method of storing PG plywood?

stacked flat on a shelf in a climate-controlled area of the shop (very-low to no humidity).

[gamn1958]

I made some shelving out of 2x4’s that are 24 inches deep and 48 inches wide.

[marmak3261]

I opened a box that I got in January last week and all was flat. I opened a box that came last week and all was flat.

I have flat shelves and store the plywood on the bottom and put some thick acrylic sheets on top.

Any warping that results from humidity changes in the meanwhile is taken care of with holddown pins or magnets. I guess I have been lucky.

[rbtdanforth]

I have some stacked in the side but the forces keeping it flat side to side are far greater than gravity