I needed to make a box to house a delicate measuring probe for my CNC lathe,
and had to hand an offcut of 12 mm 7 ply from B&Q the bulk of which had made
a new counter top for a tool cabinet.

Usual approach, make the box as one entity pinning and gluing the top and
bottom to the already fixed sides making a sealed box, sand all faces to a
good finish, then saw apart making a lid and base that you can guarantee
will match each other even if very slightly out of square.

Worked very well until we get to the sanding stage where I find I've been
heavy handed and sanded through the top ply - surely NOT - 11.45 mm thick
(measured) 7 ply each ply should be about 1.6 mm thick - no way have I
sanded 1.6 mm!

.. . so I did an experiment with a scrap of the ply, and sanded until I got
the same effect then measured how much I had removed. Answer a bit less than
SIX thou so what's going on ????

It seems that it's NOT 7 ply but 9 ply, the two outer 'plys' being only 6
thou thick and basically just a colour layer that is paper thin.

.. . .what junk is being foisted onto us these days !!!!


Andrew