Ply delaminating when warping?

[Pabs]

As in when using over enthusiastic clamping pressure? Is this what has caused this mostly optical undulation in this 6mm ply?
Ta!

 

[Cabinetman]

I’m sorry Pabs but I’m having trouble trying to see what’s happening in the pic, but will say ply normally breaks before de laminating unless the glue has failed due to water etc.

 

[Fred48]

In my experience sometimes plywood is not well made.

If you examine the edges of the plywood you may well see gaps and overlaps in some layers and this will show on the outer surface.

That is a possibility.
Fred

 

[Jaco]

I’m sorry Pabs but I’m having trouble trying to see what’s happening in the pic, but will say ply normally breaks before de laminating unless the glue has failed due to water etc.

Maybe a closer photo?

Bought a sheet of 18mm construction ply couple of months ago, the hardware store cut it up to my BOM.
Loaded onto LDV and when I started offloading at home some of the pieces had split right in the middle, some part way other right through.
Poor glue adhesion.
Received a credit and bought from another shop close by.
The ply tends to warp as well.

 

[Sgian Dubh]

As in when using over enthusiastic clamping pressure? Is this what has caused this mostly optical undulation in this 6mm ply?
Ta!

The rippling you see on that black top surface look like the undulations that sometimes occur during the final sanding to thickness that happens during the board's manufacture. The undulations occur because, for example, every now and then stray debris gets between the belt and the underside of the board as it's conveyed along the production line causing the board to bobble up and down a bit as it passes under the sander. And thinner ply is not as strong as thicker stuff making it more likely to flex a smidge as it passes through the production line.

I see no obvious evidence of delamination in that framed panel. You could possibly test for voids by tapping the panel's surface and listening for a hollow sounding 'thunk' rather than a solid ring type sound, but I suspect that may not be definitive. Slainte.

 

[Jaco]

What is going onto the black panel?

 

[TheUnicorn]

to my eyes, which may be wrong, it just looks like the black panel has been over sanded

when you put the edge of a straight edge and a small torch are you seeing obvious gaps where the light creeps through?