TromboneChat

My soldered bell had a few small acid bleed spots along the bead.  Now I notice it seems to be spreading further along the bead.  I imagine there is no way to reverse this, but is there a way to prevent it from continuing to spread.

It should spread to a certain point and stop.  I have a horn that developed acid bleed almost immediately and it has remained stable for 30 years.  I really would't panic over this.

Older Shires horns seemed to have this problem a lot.  Must be related to flux cleaning after the soldering process for the bell rim.  It's unsightly, but not serious.

Unfortunately there is really no way to stop it from spreading. Depends on how much flux is trapped, and how much makes its way out. I remember some 80s/90s Yamaha horns would have acid bleed almost all the way around the bell.

OK.  But at what point can one expect it to have run its course and not continue any further?  My bell is about 3 years old and I just noticed a new section the other day.

You could remove the lacquer around it similar to the way you'd remove brush from spreading a fire. (My apologizes for the poor timliness of the analogy, I couldn't think of a better example).  But then you wouldn't have lacquer around whatever the spots are and that also wouldn't be very sightly. Unfortunately, there's really no way to know how long it'll spread other than to say that once its finished it probably won't spread anymore. But as to when it might be finished spreading is anybody's guess.

My horns with acid bleed usually had it occur in the first few years of ownership, then it stabilized. I think the vibrations from playing help it develop, and once it's run the course, it stops spreading.

Quote from: daveyboy37 on Oct 10, 2017, 08:48AMMy horns with acid bleed usually had it occur in the first few years of ownership, then it stabilized. I think the vibrations from playing help it develop, and once it's run the course, it stops spreading.

Yeah, mine showed a small bleed shortly after I got it.  But then nothing for a long time until just recently.  So now I'm thinking what the heck?!?!

Quote from: daveyboy37 on Oct 10, 2017, 08:48AMMy horns with acid bleed usually had it occur in the first few years of ownership, then it stabilized. I think the vibrations from playing help it develop, and once it's run the course, it stops spreading.

Yeah, mine showed a small bleed shortly after I got it.  But then nothing for a long time until just recently.  So now I'm thinking what the heck?!?!