Twisted 18mm birch ply sheet

[flanajb]

If I am correct 18mm birch ply sheet should be completely flat and if it's twisted then it's been stored badly?

I took delivery of a sheet and need to make a door 1800mm long but it's twisted.

I do need to laminate both sides with Formica and am planning on using epoxy, but am now thinking that it's not worth using the sheet I have?

 

[robgul]

Yep - send it back to the supplier for exchange/refund if you bought it recently (when I buy plywood I sort/select it myself at the supplier, or as it comes off the truck if being delivered)

Rob

 

[AJB Temple]

When you say "birch ply" is it a graded baltic birch sheet? (Would be odd to stick formica to such). Or one of the builders yard type sheets (eg the birch sheets sold by Travis Perkins). 24mm sheets tend to be a lot more stable than 18mm. 18mm is capable of bending under load.

 

[flanajb]

Ok. Thanks all.

I can't use 25mm as I've made the cabinets based on 18mm ply.

I'll speak with the supplier as I have had birch before and was always sure it was flat.

 

[peter-harrison]

It depends on how bent/twisted it is. I have bought hundreds of sheets of birch ply from many different suppliers, and they are rarely flat, never dead flat. I just plan accordingly, and choose which bits of which boards I use. I.E. if it's the side of a cabinet with fixed shelves, it's OK to use a bendy bit for the sides as the shelves will pull it straight. If it has to be a shelf, use it curving up in the middle so that time and gravity will make it better not worse. I would only send it back if it's too bad to deal with using these methods, or (which I sometimes do if it's important) if I've specifically asked the supplier for flat boards.