Thread: Help - Suggestions for removing and reintalling inlays

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?

Originally Posted by ignatz

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.

That just doesn't make sense, maybe Max can pipe in since he works even more with Micarta,,, But that should have worked...

Wax
Polish
Sweat
??????


Anything ???

I'm not surprised this happened.

Is that paper micarta? What did you use on the Micarta scales to achieve your final shine/polish. Did you polish the scales up at all?

Polished paper micarta does not do well with epoxy glue. The part you need to glue the inlay on needs to be sanded down lightly or the glue will not hold.

Originally Posted by Maximilian

I'm not surprised this happened.

Is that paper micarta?

Yes

Originally Posted by Maximilian

What did you use on the Micarta scales to achieve your final shine/polish. Did you polish the scales up at all?

I sanded up through 1500 grit, polished with brown bar and then white bar on felt and finished with a wax buff. My goal was to get them as smooth as possible with what I had on hand and I didn't even think twice about the wax or other polish interfering with the bond.

Originally Posted by Maximilian

Polished paper micarta does not do well with epoxy glue. The part you need to glue the inlay on needs to be sanded down lightly or the glue will not hold.

Hmmm, the polishing, now I need to rethink this a bit and determine if I want to strip the scales and sand them so I can try the glued inlay again, use them as they are, or come up with another idea. There are many thoughts and idea's coming to mind.

Thank you Glen and Max, your input has been very helpful and this has been a learning experience, not to be forgotten.

My experience is also that epoxy doesn't bond too well with micarta. If you try it again, I would suggest leaving the micarta sanded at no more than 220 grit before you epoxy the inlay in place. Still, I'm not sure if it would work, but if it did, I would then do some refinishing on the scales with the inlay also in place. Be careful if you buff it though.

If you want to rough the surface with sandpaper and not ruin the polish you have already, mask around the part you want to sand with painter's tape. Once you sand your little diamond shape, leave the tape and it will help make sure you don't get epoxy where you don't want it.

Make sure, before you glue, that the surface is rough but clean. Buffing leaves grease behind. I would use alcohol or mineral spirits to clean the surface after sanding. Don't use acetone or naptha, these may dissolve the epoxy in the micarta.