Bent ply

Any tips for straightening a 120mm x 300mm x 6mm ply board if laid flat at 3/4 length it is 12mm off the bench.
My first thoughts were wet it a put a weight at the bend site.
Any ideas most welcome.
Damien.

steam it with a wall paper stripper Damien, and then weight it down with old batteries, bottles of water.anything like that. neil.

Which side upper or lower? Neil I have an 8"x 8"x 1" steel block I use to hold stuff down.

As it was going to cost an arm and a leg to hire a steamer so as the the crooner once sang I did it my way next best thing to steam Neil.
Problem solved I washed both sides of the affected section with HOT water placed 3 coffee stirrers end to end and placed the end closest to the bend on them bend up and placed a 5kg block of steel on the raised area 10 hours later all straight.

thought every man had a wallpaper steamer Damien.......pre requisite of marriage, lol..........

trouble is mine took it with her when she left, lol.

good to see you've solved the problem though.

neil

you have to steam a particular side, lay the board on a flat and ensure the bend hollow is to the ground kinda like this ( <--- spun 90 degrees to the right. then steam the top and then put something heavy and flat on it, or brace it down. you will never get rid of the bend fully with ply sadly, but you can straighten it out enough that when cut down into smaller sections they will be flat enough to use effectively.

ply is pretty evil when it comes to bending it usually happends when its got damp or wet and sagged or got to hot and the glue lamination have been heated enough to sofften and then re dried pulling the lamination's back together in an un-uniformed way.

The best method is actually to put it into an oven and heat it up to 50 degrees for about 10 mins and sofften the glue again, put the board flat and brace it to hell as the glue re-dries, 

Both methods are not guaranteed to work with ply, as its a lamination of some substandard materials within the core react differently.

I'll look at it one day lol temp's of 9c top for the next week the shed can stay locked, after reading a comment on my thread of the Josie being a very tender i'll build with a balsa keel to save a bit more weight.