TromboneChat

Anybody in here know the best way to remove chrome plating from a horn?

I have a super cool 3-valve G bugle whose chrome plating is flaking off in places, and I've read that getting your hand cut from chrome flakes is a great way to get a trip to the ER so I'd like to get it all taken off. (Removing it will also probably make the horn play better...they put it on thick on G bugles.)

HCl tank - an easy job for somewhere set up for auto restoration work... for Googly example, https://vannuysplating.com/

Just make it clear you don't want it sandblasted afterwards

Except auto restoration isn't usually dealing with a brass substrate. Or solder joints. Find out what the effects of the acid are on brass and solder.

Muriatic seems to have been the standard brass instrument chem clean in the Bad Old Days - and that'll dissolve the whole instrument given enough time - but I'd definitely want to know what sort of concentration and residence time might be required.

If they can reverse electroplate, I think that uses a much more dilute (sulphuric?) solution.

Either way, test on something unimportant first (waterkey/valve cap...), and then potentially silicone plug everything to keep it out of the valve block.

Mechanical methods will tend to preferentially chew up the exposed brass because the chrome is so much harder.

I wouldn't suggest trying to do it yourself. Lots of ways you could get into trouble. At least look into having it done by a professional first.

In googling around, I see ultrasonic cleaning as a possible method for stripping chrome plate. That'd be where I looked first.

JohnL wrote: ↑Thu Mar 23, 2023 2:59 pm In googling around, I see ultrasonic cleaning as a possible method for stripping chrome plate. That'd be where I looked first.

I suspect that may be another technique that falls into the category of 'yes, but only at durations/intensities that start to attack the brass', just like the other Scary Bathtub options. A strong dose of ultrasonic cavitation can easily blow out red rot holes.

Chrome plating is not to be taken lightly. Chemical means are far more likely to dissolve the brass before the chrome.

I found this:

https://www.wikihow.com/Remove-Chrome-Plating

Some of these may be inappropriate for a non-ferrous substrate or something with soldered joints.

I would not use reverse electroplating on a surface with flaking chrome. You will remove base metal where the chrome has flaked off. Not good.

This is a job for a metal plating shop. They are equipped with acid vats.
If the horn has a quality plating job it will have a nickel barrier layer under the chrome.
A soak in sulfuric acid will dissolve the chrome and the nickel barrier layer. It will not react with lead, but
it will tend to attack the brass, so some experience/finesse is required.
Reverse electroplating would remove the chrome, but leave the nickel.