So, the idea is to coat a slide with matte black alumahyde and polish the sides glossy, leaving the top and serrations matte. Will it work? When is the best time to try to do it? After curing, or during? The plan was to use some turtle wax scratch remover to do the polishing. Is alumahyde thin enough to worry about wearing down the edges of engraving?

Not really. You can take the dull look to a sorta oiled look but no where near polished. Alumahyde is much thicker than cerakote. I have not used it in a long time however.

Wish I still had my Alumahyded ashtray, I would have been game to test it for you.  It's paint, applying a polish I would image add a bit of gloss like appearance.  Maybe one of those new super ceramic polishes may enhance the shine more?

Thanks for being willing to give it a shot. I've got a blem non functioning slide that I bought to practice engraving/finishing. I'll post up pics when finished in case anyone else gets curious about it. If the alumahyde turns out poor on the practice slide, I'll clean it off and try another finish. This is all a first for me, but can't know until you try.

I would love to see pics.

Ok, I'm sold on the Alumahyde product. I did a quick coat on the test piece and baked it yesterday evening. The only issues with the coat had to do with my spray skills, but I can work on that.

This morning I took the slide and ran the dremel with a polishing pad at about 7500rpm with some Turtle Wax scratch and swirl remover. Ignore the white flecks in some of these, it's just the turtle wax, not the alumahyde.

I did the engraving side first. I wanted to see if the edges of the engraving would get worn away:


I then did a small section on the other side to get better contrast:


It's mirror smooth:

Wow, that looks really good.  I might have to give alumahyde a second chance.

That is awesome

I've played with enough AH to have figured it would polish up good, on a couple things I did I've used 0000 steel wool to buff out some blemish's when the nozzle went wonky on me or the AH had more grit appearance to it which happen to be their earth brown that sprayed like crap.  AH definitely comes with it's own challenges to get a good coverage at times.

Thanks all. Gonna start work on the real slide in the next couple days. We'll see how it goes!