Removing corrosion from brass horn

[Chuck]

Hi Alex,

I'd try some toilet bowl cleaner.
Here in the states, there are many inexpensive
versions of it sold at discount stores.

Look for the kind which has some form of diluted hydrochloric acid in it. Hydrochloric
acid is also called muriatic acid. There may
be other names for it as well, on your side
of the Atlantic ocean.

I've used various forms of cheap toliet bowl
cleaner with great success cleaning up many
hundreds of small brass and copper parts
which had on them the same black and green
corrosion your horn has on it.

These small parts I have cleaned are the
contacts out of ancient electro-mechanical
telephone switching equipment. I collect
that old stuff, and have a working 200 line
telephone exchange in my house.

Some of those old contact-bank assemblies,
fuse panels, and mounting jacks were so hopelessly corroded, that they were passed over by everyone else but me. They had sat
in a pile for well over 40 years, corroding
away.

I carefully disassembled them, and threw all
the hundreds of small brass stampings into
a large baking dish full of that toilet bowl
cleaner. I left them in there for a few hours, some of the most stubborn ones
overnight. After a rinsing and drying, they
were all bright and shiny, and ready to be
put back together and used!!

Some of them did turn a reddish color.
But, getting the thin red layer off is much
easier than the first thick black layer.

Compare that to the time it would take to
clean each one by hand using steel wool...

I'd say get some of that cleaner
and try it on a rag on
a few spots and check to see what's happening.

You're trying to do it all mechanically with
steel wool. The muriatic acid will help.
Try it and see.

That's my suggestion, good luck!

Let me know what your results are.

Chuck

[Lucius1958]

I have used toilet bowl cleaner on brass organ reeds, and the results have been quite satisfactory…

Bill

[kirtley2012]

In that case, would cola work also?

[FloridaClay]

I have a friend who swears by using oven cleaner, but be very careful if you use that. Dangerous stuff.

I doubt cola would be strong enough.

Clay

[Chuck]

Kirtley,

The subtitle of this thread could be:
"Better living through chemistry"

You've already found out that the thick black
gunk on your brass horn is not coming off
easily at all. It's a lot of work to remove
it, unless some rather strong chemical is
applied, which will do most of the work for you.

That chemical is hydrochloric acid.

It can be obtained in diluted form in cheap
commericial cleaning agents already discussed.
Get some toilet bowl cleaner.

Stuff such as cola, vinegar, etc. just is not
strong enough to do what needs to be done.

So, you can continue to fight this, or you
can get some strong stuff that will do the
required job. If it's safe for organ reeds,
it will probably be just fine for your horn.

Again, once you get some, put a little bit
on a rag and wipe it on and watch what happens. Then report back to us the results.

Chuck

[FloridaClay]

And wear some rubber gloves.

Clay

[kirtley2012]

What is the best lacquer to stop the horn tarnishing again?

[Chuck]

20 years ago, I had the same question.
What lacquer works best to protect brass
and keep it bright without tarnishing?

Well I ended up asking around amongst the
clockmakers.

They explained to me how to do it.

I had some 6 inch long, .375 inch diameter
machined brass posts that needed to be protected.

I was told to get some good quality clear
lacquer in a spray can that's intended for
automobile paint work. They also told me
how to prepare the brass.

The brass needs to be cleaned and shined
beforehand. Then, right immediately before
spraying the first coat of the clear lacquer
it needs to be washed thoroughy using
denatured alcohol. Care must be taken to
clean every part of the surface using the
*denatured* alcohol (not isopropyl alcohol
nor rubbing alcohol, or anything with water
in it). Put some on a clean soft paper towel
and wash the whole works. Let it air-dry.
Do not touch it.

Then, after it is clean and dry, be sure not to touch it with fingers or anything else.

The part to be coated should be warmed slightly.

Then it needs to be hung up so that it's
suspended freely in midair, allowing easy
access.

Then spray a very light first coat.
Allow to thoroughly dry. (At least a few
hours, overnight would be better).

Then apply a 2nd coat.

One of the worst things is to spray too
thick, and have it run. If it does that, you
have to wipe it off and start over.

I had those posts hanging from a string and
wound up the string so the posts would rotate
as they hung there.

That made spraying them easy.

20 years now in the future, and all 6 of those
posts are still as bright and shiny as the
day I sprayed them.

Automotive lacquer worked fine for me.

Hope this helps some.

Chuck

[De Soto Frank]

Don't know about the availability over there, but Nixon ( Nickson?) makes a lacquer specifically designed for coating polished metals...


You might also find a shop that repairs / refinishes brass band instruments and ask them what they would suggest...


It might also be worth your while to let said shop do the final polish and spraying of your horn.

[JerryVan]

What is the best lacquer to stop the horn tarnishing again?

Kirtley,

Once a horn is polished nicely, you only need to polish again maybe once a year, (depending on your local environment, humidity, etc.). Any coating will only last so long, then it will be a mess to remove it, polish & recoat.