TromboneChat

There’s a place not too far from where i live that sandblasts car parts and stuff, i’m about to get a horn that’s ugly and was wondering if i could take it to them. I’ve emailed them to see if they would do it, but test on a trashed up marching baritone. I’m way too scared to take any like steel wool to my horn or anything. Should i strip the lacquer off first, it’s kind of half lacquered and spotty.
I can always just leave it as is and be happy, but this could be cool too.

Sand blasting will remove what lacquer remains. I don't think it would make a difference in the end result, I.E. you won't be able to tell where there was and wasn't lacquer. That being said, a few people in the past have tried satin brass finish on tubas, and it's an enormous pain to take care of if you want it to keep looking "fresh." Also remember that sandblasting will remove some metal from the instrument, and that may change how it plays, for better or worse.

I find it interesting how a satin finish was popular 100 years ago and now it's coming back. The results would depend a lot on the media used. I would think that anything used on car parts would not be suitable for brass at all.

Doug Elliott wrote: ↑Thu Jul 02, 2020 11:55 am I find it interesting how a satin finish was popular 100 years ago and now it's coming back. The results would depend a lot on the media used. I would think that anything used on car parts would not be suitable for brass at all.

Thanks for the input, are you thinking coarser or finer? I can probably test a couple different mediums on my scrap horn

Check out the photo half way down:
https://www.popularmechanics.com/cars/h ... -15997905/

I would suggest softer. You may find that walnut hell provide plenty of abrasion. You don't need and or carbide bead.

I was able to blast epoxy solder mask off of copper using baking powder in a and blaster (with an airbrush tip).

Elow wrote: ↑Thu Jul 02, 2020 12:12 pm

Doug Elliott wrote: ↑Thu Jul 02, 2020 11:55 am I find it interesting how a satin finish was popular 100 years ago and now it's coming back. The results would depend a lot on the media used. I would think that anything used on car parts would not be suitable for brass at all.

Thanks for the input, are you thinking coarser or finer? I can probably test a couple different mediums on my scrap horn

Even fine sand would probably remove too much metal. (Maybe a method to thin a too-thick bell?) Salt blasting might be a little gentler, but probably still inappropriate for a brass instrument.

However, since you're clearly a determined experimenter, with plenty of time on your hands, give it a try on your "scrap horn" and report back to us. The worst thing that could probably happen is that you further trash the scrap!

Posaunus wrote: ↑Thu Jul 02, 2020 12:24 pm The worst thing that could probably happen is that you further trash the scrap!

I like how you think

Be aware that air pressure needs to be "much" lower than would be used on a car part. It is very easy to deform a bell with a high pressure media blast gun. Agree with he above, a finer "grit" will give a cleaner look. Having the horn relaquered or plated would help keep it looking good. Blasting gives a larger surface area which tarnishes much quicker than a polished surface.
M

It seems that some people distinguish between matte finish and satin - matte is nondirectional and done by blasting while satin is brushed in one direction.

On steel, several sites warn that the surfaces will rust instantly if not protected; I'm guessing brass would get that patina I find ugly pretty fast too.

Old style "satin finish" was not brushed. I'm not sure it was done with blasting either I think it was just a plating technique, on top of polished brass.

the media you are most likely going to want to use is soda - as in baking soda or possibly walnut shells. brass is terribly soft compared to the steel in a car parts and care must be taken to not damage/deform

The old silver plated Conns were media blasted, with the shiny parts being masked during the blasting. They were then plated.

Either media blast or "scratch" finishes are governed by the aggressiveness of the media being used. It is possible to do very fine, "bright" finishes, as well as very heavy, "course" finishes using either technique.