As you know, plywood is a "layered up" substrate that is produced under tons
of pressure utilizing a variety of glue and temps for various applications.
Many times I have taken back to the shop a sheet of Plywood with just such a
laminating flaw in it. Didn't do anything negative to my project, just ticks
me off cause, I don't see it in the dim lights of the Lumberyard. From my
experience , I'd say, it's a crease that got caught in the press and sneaked
passed Q.C.
"Graaeme" wrote in message
om...
I have been restoring a plywood boat approx 20yrs old & have noticed a
ridge in one sheet of ply running accross the sheet in a uniform
manner. I have removed paint down to the wood & everything seems OK,
no sign of damp or delaminating.
Is this quite normal for ply to do this or could there be an
underlying fault? If so is it best to just ignore it as it just seems
cosmetic to me. By the way its nowhere near the end of the sheet or
any other obvious weak point.

Thanx,
Graeme