Quote Originally Posted by ignatz View Post
Just some thoughts:

Where did the bond fail?

There seem to be two possibilities.

A) The first possibility is that the inlay popped out with its coating of new epoxy still clinging to it but not to the Micarta.

For what it's worth: When I used to build model RC airplanes, I was told to never try to put a layer of epoxy on top of another layer of epoxy. The general wisdom at that time being that although epoxy bonds wonderfully to other things, it doesn't always bond reliably to itself.

Micarta is multiple layers of cloth bonded together with some sort of resin... usually epoxy. That suggests that trying to use epoxy to bond the inlay to the Micarta would not produce a reliable join. How true this is I cannot say. Epoxy formulations have changed over the years so that what I heard long ago may no longer be true. Nevertheless, you might want to test out the bond strength with some of the epoxy and a scrap of the Micarta.

B) The other possibility is that the inlay popped out totally clean without any of the new epoxy holding on to it.

If this is the case, than the new epoxy couldn't get a good grip on the metal of the inlay.

Was the inlay absolute clean and degreased before you applied the epoxy?

Did you remember to roughen the back of the inlay with some sandpaper?
Yes, ( A) the inlay came off with the glue attached to the inlay ) is exactly what happened.

Now, because I want to use the scales I made up, I am rethinking whether I want to use the inlay or keep it tucked away for use on another set of scales in the future.