"Jim Levie" wrote in message
...
On Sat, 3 Sep 2011 18:09:36 -0400, "Existential Angst"
wrote:

"Wild_Bill" wrote in message
...
I don't recall the details about the earlier discussion wrt
metal-over-substrate, but it wasn't about wood-epoxy filler products, not
that I recall.

A while ago you were asking about adding a skin over foam or MDF or
maybe
some other substrate(s).

Good memory!!
Apropos of that excellent discussion, I came up with an elegant solution:
No glue at all!!
I just had delivered 1/32" sheet alum, and 1/2" ply, and I'm just going to
let the alum "float" or slide on the ply substrate, as it will be very
well
constrained along all 4 edges, by 3/4 x 1.5 x 1.5 (1/8") channel.

Eventually I WILL use glues of sorts, as I think that altho mechanical
engineering insights in that thread were valid, that I'll still be able to
generate add'l stiffness without the aluminum shearing the top layer of
ply
off the wood. It will be an ongoing experiment.

But, as it is, the ply itself is stiff enough, just more would be better.

Industrial type contact cement would be an easy way to bond the
alumininum to the plywood and might work for you.

Contact cement was mentioned a few times.
I wonder if one type of adhesive will be less prone to shearing off a ply
layer than other types.
I spose if the adhesive itself has some kind of give.....

Also, with contact cement, I"ll get a free buzz.....





Then there was an even earlier topic of screws with deep/aggressive
threads, such as those used for plastics.. but you were contemplating
using them in metal (mounting a device to metal door frames, IIRC).

You have a scary memory!! LOL
Indeed, and I found that the coarse drywall screw was actually pretty well
suited for this, esp. with being so hard -- but indeed a bit brittle..
I found some other type screws as well, but I'll have to dig those up --
sumpn with "mixed pitch threads", or sumpn.

My choice in screws for this application would be what I call "cabinet
screws" They have a conventional countersink head, a straight shank,
and fairly deep threads. The screws are meant for use with wood or
particle board and thus have threads deeper than a wood screw, but a
bit less than a true particle board screw. Unlike sheetrock screws
they aren't brittle.

Bingo! Dats what I had gotten!! Couldn't remember.
NOW to see if I can find them.....

Indeed, a sturdier screw, not so brittle.

--
EA