Estimating dent repairs: mid bow, valve tubing

[TheGoyWonder]

A couple tubas I'm looking at are rough but the biggies are good: the bell is intact and the valves allegedly have compression. I'm trying to get a good idea of what the limits of supermagnet dent removal, and what it costs. Dents in lead pipe are intolerable, in valve tubing very unwanted...basically the further you go the less it matters, is my thinking.

If there are dents in the 4th valve tubing, is it an easy job to have a tech run magnetic balls through it, and at least keep it nice and open? How near a joint can you get without him having to unsolder and making a big deal out of it?

What if one of the middle bows is rough, is that harder because it is conical? I'm not sure the technical term, but I'm counting forward from the bottom bow and it's the third bow that is fairly well chewed up. I would be going for an 80% solution, opening it up but nothing like a restoration. Say there's 12 inches of tuba that are 60% mangled, in the third bow as I call it. What might it cost to iron out some valve tubing and a bow?

[UDELBR]

Magnets & balls won't help much (if at all) on smaller tubing. It just doesn't have the power. They're best used on branches & bows.

[bort]

So how *do* you remove dents from the smaller tubing?

[UDELBR]

Yup. Dent balls.

[TheGoyWonder]

Secret bonus to playing tuba: Only the tuba has a bore large enough to fix with mag balls. Cool.

Sounds like dent work is largely possible, and dents should be less scary than bad rotors, linkages, or bells? A couple hundred in dent work would go pretty far?

[Dan Schultz]

My general rule of thumb is 'removing dents can NEVER be estimated from the description of the customer'. There is ALWAYS more involved.

Magnets are of little or no use on the smaller tubing in the valve circuits on the leadpipe. You have to be able to pull dent balls of increasing size through the tubes with cables. The 'old-timers' spent a lot of time 'shaking' dents out by making dent balls peck against each other inside the tubes.

[Untersatz]

tubing down to c. 3/4" i.d. can be annealed

annealed=what exactly??? (in simple plain English)

[J.Harris]

Annealing is simply heating a metal to remove its temper. In other words, heating it to soften it and make it more malleable.