TromboneChat

Would grain alcohol be okay to try and dissolve gunk in my inner slide that remains after a professional chem clean?

Hard for me to imagine that there's much "dissolvable gunk" after a proper chem clean. Usually just mineral deposits (not dissolvable) or residual polishing compound (if used) or oxide (both removable after repeated swabbing of outer slide.
In any case, I expect that pure alcohol will do no harm - evaporates rapidly.
Good luck.

Here's a photo:https://www.dropbox.com/scl/fi/dm5eljsb ... h3nvs&dl=0

Take it back to the professional and ask them to finish the job?

Your photo link doesn't work for me.

Here's the pic.

Never really seen gunk like that.

tbonesullivan wrote: Mon Jul 20, 2026 6:41 pm Never really seen gunk like that.

At least some of that looks like pitting to me.

That has not been fully cleaned. It needs to be put back into the pickle for longer. It should then be scrubbed with a bristle brush on a slide rod, with detergent to remove the remaining deposits.

JohnL wrote: Mon Jul 20, 2026 7:08 pm

tbonesullivan wrote: Mon Jul 20, 2026 6:41 pm Never really seen gunk like that.

At least some of that looks like pitting to me.

I agree; it looks like pitting to me, too.

Is the photo of the interior of an outer slide? Do both upper and lower appear similar?

Do you know the history of this trombone and how this could have been caused?

That looks like inner slide corrosion to me

These photos are of the inside of the upper inner slide, where the leadpipe is. Here is one photo from before the chem clean and two after.

@hornbuilder
What kind of solvent can I use--vinegar, acetone, grain alcohol? And is a regular flexible snake adequate, or do I need a stiffer bristle?

Again. That has not been completely cleaned. Take it back to the shop and ask them to finish the job