Relapping/replating Rotors

Neo_Bri · by **Neo_Bri** » 2020-01-28 12:56 p.m.

HELLO!

I have a horn I'm borrowing - a (French) horn. Paxman. Nice. But might have some worn-out valves.

What do you do about replating/refinishing, etc.? I imagine not all techs do that kind of work, and I wonder if you've had any experiences having this done that may be valuable for both myself and others.

Burgerbob · by **Burgerbob** » 2020-01-28 1:12 p.m.

Have the bearings been swedged? That's usually the first step.

tbonesullivan · by **tbonesullivan** » 2020-01-28 1:15 p.m.

Where are you located? There are plenty of techs that do that kind of work, which is pretty standard for a french horn overhaul.

Bonearzt · by **Bonearzt** » 2020-01-28 3:37 p.m.

The best I have used is Jim Becker at Osmun Brass!!!

Neo_Bri · by **Neo_Bri** » 2020-01-28 8:09 p.m.

I'm in Utah, and I don't think anyone here does it.

Cool. I think I'm gonna look up some videos of what they do, since I don't really understand he process.

Burgers, I don't know what "swedged" is, and I have the horn on loan, so nothing yet. But I'll look into it.

Burgerbob · by **Burgerbob** » 2020-01-28 8:29 p.m.

Apparently, "swage" is the correct spelling. Color me surprised!

I don't do it myself, of course, but it's basically just smushing the bearings back in a little bit so they seal well again. A WORLD of difference on worn out valves (which is usually the bearings being worn out through friction over time).

A tech can chime in, but this is a lot easier, cheaper, and usually the first step in bringing valves back from the dead.

Posaunus · by **Posaunus** » 2020-01-28 8:31 p.m.

If Eric Edwards (a top brass tech) sends rotors all the way from Texas to Massachusetts for restoration:

1. It must be a tough project, to be undertaken only by a specialist;

2. Jim Becker must be such a specialist. (Jim did a great job on one of my trombones.) :good:

brassmedic · by **brassmedic** » 2020-01-28 9:38 p.m.

The valve needs to seal inside the casing, not at the bearings. If the bearings are loose they should be swaged, but that won't fix a worn out valve that's leaking. The valve core has to be heavily copper plated so that it is very slightly larger in diameter than the casing, then lapped into the casing. After that is done, the valve core has to have a thin layer of nickel plated over the copper, then lightly lapped again. It's very labor intensive, and unless the tech does plating in house, it has to be sent out at least twice to the platers. It's not cheap.

I think swedge is an acceptable variant spelling of swage.

tbonesullivan · by **tbonesullivan** » 2020-01-29 10:02 a.m.

This is definitely a good thread for people to read who don't oil their valves enough. Just because they "aren't slow" doesn't mean they aren't lacking in lubrication. There's no way to prevent all wear, but it definitely can be reduced.

hornbuilder · by **hornbuilder** » 2020-01-29 10:10 a.m.

I tell all my clients "you cannot over-oil a valve" But you certainly can under oil!

KCinAZ · by **KCinAZ** » 2020-01-30 1:07 a.m.

I had all 4 valves on a double French horn overhauled (replated/relapped) 4 years ago. It cost ~$300 per valve and took many months because they were sent out in batches to the plater (and I wasn't in a hurry). It's not a quick process. They work much better now. If I'd wanted it done faster, it would've been more expensive.

If you can find someone who does the plating then it'll be quicker.

Bonearzt · by **Bonearzt** » 2020-01-30 11:17 a.m.

[quote="hornbuilder"]I tell all my clients "you cannot over-oil a valve" But you certainly can under oil![/quote]

EXACTLY!!!!!!!!!

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Relapping/replating Rotors