"CHale" wrote in message
om...
"Dave Marsh" wrote in message
...
Hi,

snip
My idea so far is to glue 4 metal hex spacers to the back of the
aluminum
panel. I can then bolt the PCB to that. Alternaitevely the same kind of
idea
but glue the flat heads of 4 countersunk M3 screws to the panel instead
(I'm
thinking the contact are of a screwhead will be greater than that of a
hex
spacer with its central thread hole).

So far I've tried an epoxy ("plastic steel" by Draper) with the hex
spacers.
Initially it seemed ok, but with a small amount of leverage the spacers
came
away.


I used Tracon 2151 epoxy for aluminum applications a lot. Its CTE is
quite decently matched to aluminum, which helps a lot if the assembly
sees temperature variations, etc.--C. Hale

Many thanks for the epoxy recommendation. I will give that a try. TBH when I
have done testing to breaking point, there is always epoxy left on the
aluminum, but never on the screwheads/spacers. So it seems to me that the
epoxy is having most difficulty adhering to the nickel plated brass
(spacers), or the zinc/stainless steel (screws).

Someone elsewhere suggested anodized aluminum spacers. Maybe they would
stick more firmly? (if I can find a source for them).

Dave