TromboneChat

So I recently purchased a Getzen 3062 AFR off of eBay. When I received the horn and brought it to my tech he pointed out some red rot on the slide and told me that I would have to replace both outer slide tubes. I've never dealt with red rot before, but luckily he only quoted me a ~$200 for the parts and labor. So it's not a huge deal, especially since I got the horn for a good price.

Anyway, that led me to thinking about red rot. Personally, I've never seen red rot on older trombones. The only time I've encountered it was on newer instruments. I've only seen it 3-4 times in my career with friends of mine.

Is there a reason for this?

You don't have a large enough sample size. Red rot occurs on plenty of older horns.

Lots of old Bachs with red rot, especially from southern states.

That being said, modern brass seems to red rot pretty quickly- I think several techs have said as much lately.

I had red rot on both my 80's era Bach 42B and a 50B, before I finally had to ditch them in the early 90's. I bought a Getzen 1050 not long after that, which about 20 years later developed red rot on both the outer brass slides. So it happens a lot on older horns. Unless restored that's usually the end of them. I had always liked the Getzen, so this time I didn't sell it; instead I let BAC restore it with modifications, including light weight nickel silver outer slides, a rounded brass crook and interchangeable lead pipes. Head and shoulders above it's former self. I know BAC has had some customer service issues, but I had no issues at all.

So what can you do to slow or stop red rot?

whitbey wrote: ↑Sun Mar 15, 2020 7:55 am So what can you do to slow or stop red rot?

Red rot requires humidity. Horns "rode hard and put away wet" will develop red rot faster. Corrosive atmospheres (like the sulfurous air near a volcano or where there is severe air pollution) also speed up red rot. Finally, acidic deposits are not good. If you must drink sodas or black coffee when playing, more frequent horn baths may be in order.

Silicone oils (or oils in general) will provide a barrier against moisture. You might try coating the inside of the outer slide with some oil (may be tricky to do without really messing up the slide).

Is it red rot or acid bleed and/or surface corrosion? Is there any leaking or break through yet? If not I would say replacing the outer slide tubes is premature.

Now, there have been some who feel that the more modern drawing techniques result in less work hardening of the brass, which in turn makes it "softer" and more likely to develop red rot.

With old horns you have survivor ship bias. The best horns that have been taken care of are usually the ones that get sold.