Restoring an Antique French Horn Project #5: Fitting the Loose Valves | Electro-Plating

[@davemiller7633]

I think the work you're doing is remarkable, especially the detail involved in soft-soldering the tiny holes. Electroplating is kind of magical...a liquid solution bearing solid metal! It's going to be awesome.

[@Jared_De_Leon]

Glad you got a real plating setup, results look much better!

[@flash7355]

Exciting stuff

[@amsmithonline]

Nice to have you back, Art. Looks like you're getting control over the process. Did you try buffing the copper plating? A bright finish on the copper should improve the surface finish of the nickel surface as well.

[@TheBrassandWoodwindShop]

I did try that with mixed success. I may try it on some of the other valves.

[@goldenluthier]

Nice results Art! But if the rotors are in such a bad condition it wouldn't be better if you construct 4 totally new rotors on a lathe?

[@TheBrassandWoodwindShop]

That would be VERY difficult to get everything to line up just right. It could be done, but it would be far more expensive. That is a good thought though. Maybe I should try that for an experiment to see what happens.

[@goldenluthier]

@@TheBrassandWoodwindShop I am thinking also to make an experiment in an old tuba, in cooperation with local technicians who specialises in 3d scanning and cnc lathe. Maybe this make things much more easier.. but for the time this is only a thought

[@beautgrainger147]

I'm looking at DIYing a valve job on a rotary trumpet which is cosmetically great with terrible valves (am a machinist and amateur horologist).. Tbh, this looks less complicated than I'd imagined - my valve axles look to have been peened to expand them to fit and I'm concerned about lack of concentricity in and between the casing diameters (and same for the rotors). I've thought of ways to address all the potential problems which might be involved and it could hypothetically mean taking the valves back to a tight spec but going down a rabbit-hole of a path to get there.. thinking multiple steps to regain concentricity of and between parts. In terms of the actual plating, there seem to be a greater number of easy to find informative videos which cover nickel but more uninformative videos for copper. One thing which has come across, is the idea of adjusting the voltage by watching the formation of bubbles, maybe setting low then increasing it to the point that all of the bubbles are breaking free quick enough not to leave spots - then further helped with agitation. The finish of the nickel will reflect the finish underneath.. how about plating oversize then polishing or burnishing the copper, with a quick acid then distilled water dip so the nickel still sticks well? - I don't know much about the copper plating stage. Thank you for posting

[@torchandhammer]

You might try fingernail polish to mask the ports. Get blue, the reds and pinks are too close to the copper in color. Comes off easy with acetone. I plate at 6 volts and about 2 to 3 amps. Starting with 5 minutes and tapering down to 1 minute at a time as the fit gets closer. It goes on very smoothly The most important thing is to electroclean the part before plating. Washing with soap or solvents won't get it clean enough and the plating will peel off. Look for a product called Tivaclean. The plating doesn't go on evenly. It goes on thicker at the edge of the rotor and the spindle that are facing down in the solution. Also around the edges of the ports. The old rotor will not be round or concentric and neither will the casing so it takes a certain amount of repeated plating and lapping to true everything up. It can be "tight" in the casing but still leak around low spots.

[@TheBrassandWoodwindShop]

Thank you very much for the information. I was thoroughly discouraged after trying several times with no success. I have done some touch-up plating, but I gave up on immersion plating. I think what I may have been missing is the electro cleaning. I will try it again and see if I can make it work.

[@Quadstriker]

Part elbow grease, part chemistry, part witchcraft