mkr5000 wrote:

Like an idiot I had some walnut plywood cut and didn't consider the
grain direction on it so I'll need to apply some veneer over some
pieces.

Haven't used veneer in a while and when I did it was self adhesive
stuff I believe.

But on material without backing, what is the absolute best way to
go?

Contact cements are hit and miss -- there are some good professional
ones though.

I have some 3M hi strength 90 spray (damn good) (but edge cleanup?)

Also have some 3M 468 transfer tape at my disposal I could use.

I know with the 3M 90 it will stay put but concerned about cleaning
the excess adhesive.

We used to use cascamite and place heavy weights onto the veneered
areas plus gramps around the edges , much depends on your thickness
of veneer though some glues will leech through on some timbers or
stain .

Damping the face of the veneer to be glued does help with leeching
sometimes on veneer if your using water based glues

Its probably easier in the long run just to replace the ply and keep
your other cuts for other projects