Stoopid soldering question

[Joe Baker]

Okay, I've got several junker horns that I'm willing to risk to my own soldering skills, and I've gotten - er - good enough to solder junk horns. Now, I've just received an e-bay $100 "American Euph"/Baritone/whatever. It promises to be a passable instrument -- valves seem okay, not too many dents, slides move well, but the valve section is not attached. ALL of the braces are unsoldered, the leadpipe is unsoldered -- I taped it up and it plays really well, but I need to solder it together.

My predicament is this: when you have a piece that needs to be put into position, and then soldered in several places, do you just apply the flux to ALL of the areas to be soldered BEFORE soldering any of them? That's my plan, but it looks to me like some of the braces are close enough together that soldering one will likely cause the flux to run away from another.

Another question: I've seen pipe-fitters stuff bread in a pipe to hold back dripping water while they sweat tubing together; I'm thinking of doing something like that to keep solder from dripping into the piston while I attach the lead-pipe. Does anyone have a better suggestion?

I'm interested in how some of you guys that do this all the time solve such predicaments. I'd be grateful for any help you could offer.
_____________________________
Joe Baker, who hopes to accomplish this WITHOUT the usual third-degree burns.

[Chuck(G)]

I think some of your problems may be due to excesses.

Solder isn't epoxy glue or caulking. Parts to be soldered together must be clean and in intimate contact with each other.

Flux the joint, heat it, remove the heat and apply solder. If you've doné things right, the solder will be sucked into the joint by capillary action. Reapply heat if necessary to get a good solder flow. Don't apply solder and heat at the same time or you'll have a mess. If you didn't get the fit right and there's a gap, stop. Don't try to fill the gap with solder. Go back and re-do your fit.

Good preparation is 90 percent of the job. If you've done things right, the actual soldering's a snap.

If I'm soldering braces or wires, I like to flux after everything's been clamped in place (use iron wire to hold things together), since braces tend to have most of their holding surface along the edges and not the interior and I don't want any flux remaining on the interior of a joint. Clean up any excess flux before soldering.

I keep a spray bottle of water around when I work, so when I'm through soldering a large joint, I can rinse the excess flux and crud off right away. Flux is very corrosive--don't leave it sitting on the horn for longer than necessary.

If I'm soldering a ferrule, I'll tin the parts to be soldered beforehand and then join them without using flux, which keeps down acid bleed and produces a very sold joint. But again, fit is extremely important.

If you've got a silverplated horn and are worried about running solder all over the nice finish, get some solder resist (or solder repel) from Ferree's that can be painted around the joint before soldering. Solder won't stick to it. In a pinch, you could probably also use a permanent Magic Marker to accomplish the same thing.

Remember that solder has very little mechanical strength by itself--the strength of the joint is largely determined by the fit of the components and the even distribution of a thin film of solder between them.

And you'll usually have to clean up a bit around a joint. If this is a silver horn, I hope you used resist. If it's raw brass, you can purchase scrapers from Ferree's that will allow you to scrape most of the excess solder away, then finish off by buffing.

If you're soldering a leadpipe and everything fits together right, there should be no reason to fear solder getting into the valve casing. If there's a real cause for concern, use gravity to your advantage---solder won't flow uphill.

Hope this helps.

[Joe Baker]

I think some of your problems may be due to excesses.

Chuck, I think just about ALL of my problems are due to excesses

Chuck & Andy both, thanks for the advice. I've very much to learn, and this gives me a significant push along the way.
______________________________
Joe Baker, whose instruments HAVE had a tendency to be heavier after he's worked on them....

[Chuck(G)]

If you want to know more about repair, get yourself a copy of the Erick Brand repair book. Ferree's sells it, and for what it's got, it's a bargain. Written donkey's years ago, it's still full of great information.

I should've probably added that you want to use 60/40 (Sn/Pb) solid (not flux core) solder. I like Sta-Kleen as a flux--I've never had problems with it.

Also a propane torch is fine--but not one with a huge tip or one of those weedburners. Bernz-o-matic makes a good little torch that seems to have the right size tip for general soft-solder work:



Hope this helps.

[Chuck(G)]

"Repair chat" is about as interesting to me as jock itch,

So, Joe, are you a miconazole, chlotrimazole, tolnaftate or undecylenate type of guy?