span strength of 1" plywood

[matlark]

Hello,

I would like to know if I build a 2'2'96" box out of 1" plywood sheathing (think diy altitude test chamber) would it be able to withstand a 4psi differential. I am looking at testing products at no greater than a simulated 9000 ft.

Thanks

 

[dhengr]

Matlark:

Dig out your old Strength of Materials text and do a little reading and math. 4psi is 576 lbs./sq.ft. on a 2' span from side to side. What bending stress in 1" thick mat’l.? Then, each sheet also has a 576 lb./ft. of length compressive (column) loading on it. 1" plywd. probably won’t work. You might be better off seeing if you can find a piece of 2 or 2.5' dia. thick walled pipe, 8' long, and putting appropriate ends on that for your test chamber.

 

[matlark]

Thanks. From my research I didn't think it would work, but I thought I would get a second opinion.

 

[Duwe6]

Thin-wall pipe and 1/4" to 3/8" end plates will work for that small a vacuum.

 

[MiketheEngineer]

Go to APAwood. They are the authority. 4 psi is actually quite a bit - 576 psf.

Good luck.

 

[SnTMan]

A long time ago I was making some vacuum form tooling from plywood. Ended painting the whole thing with a couple of coats of laminating resin. The plywood wouldn't HOLD a vacuum

Regards,

Mike

 

[matlark]

Thanks for all the replies. What would be the minimum thickness of steel plate I could get away with?