Any advice on soldering?

[TubaOrpheus]

Hey guys. I have a raw brass tuba that has 2 loose braces (I'm assuming the solder joint failed) and 1 brace that has come off completely. I'm the type of person that likes to learn how to do things and be hands-on with repairing and building things so I thought I might give soldering a try. I've read the few threads about this on here and saw that about half of the posters recommend just letting a professional do it. If I had a silver horn or even a lacquered horn I might be tempted to let them handle it but since I have a raw brass horn, I'm not worried about looks necessarily. I've already seen a quick demonstration on it and I've done some research so I feel pretty confident that I could pull it off but was wondering what you (meaning those of you that have experience) thought or could share any advice?

Thanks!

[Donn]

Don't heat your work up so much that other joints start failing. Particularly where tubes are joined together, where you depend on the solder for a seal.

[Art Hovey]

It's not rocket surgery. As Goodgigs said, clean the surfaces well. A dremel tool with a buffing attachment works well, but fine sandpaper will do. Put a thin coat of soldering paste where you want the solder to go.

I use Radio Shack rosin-core solder, the thin kind. Make a little hoop or spiral of it, lightly coated with paste, and put it between the tuba and the foot of the brace. While heating it with the torch, press the parts together. ( In some situations it is necessary to press the brace in position with the tip of a screwdriver.) The solder will melt suddenly and the parts will snap together. Stop heating and keep the parts pressed together for maybe 30 sec until it solidifies.

I prefer this method because it solders the whole area under the brace (rather than just the edges) and leaves little or no solder to clean up outside of the edges.

[UDELBR]

I use Radio Shack rosin-core solder

Why rosin core?

[Art Hovey]

Because that's what I found. It works. The new-style plumbing solder is not so easy to work with. Sometimes a little melted rosin needs to be cleaned off, but that's easy to do.

[Dan Schultz]

I use Radio Shack rosin-core solder

Why rosin core?

I was going to ask the same question. I use LOTS of solder and it's always solid wire type... usually leaded (63/37). If you choose to used leaded solders as I do.... stay away from any higher lead content. There is a 50/50 leaded solder but stay away from it if you are working on silver-plated horns. Silver LOVES lead!

Don't expect to find leaded solders at hardware stores. I usually buy it at Hobby Lobby or other craft stores that handle supplies for stained glass work.

You don't need heat higher than 450 degrees or so for leaded solders or even 2-3% silver-bearing solder. You do, however, need enough heat to get the adjoining surfaces up to that temperature fairly quickly. Fit your parts to within .001" or so. After cleaning up both of the parts in the areas that will be soldered... apply acid flux and put the parts together. Hold them together with wire. Concentrate the heat on the larger or heavier part and heat until the solder will 'wick' between the parts.

Practice makes perfect. You can remove excess solder by applying a LITTLE heat and wiping with a cotton cloth.

[MartyNeilan]

My wife always tells me to use enough flux (aka paste).
If you don't use enough, the solder won't flow into the joint well or stick to the brass. The more flux I use, the more substantial the joints come out (one of the biggest difference between my "earlier" and "later" work.)

I agree about putting a small piece of solder under the middle of a brace, instead of just hitting it at the perimeter. I save all the "scraps" or excess blobs that flake off and use them for that purpose; they are usually flat already.

Definitely have a water spray bottle nearby, otherwise a large joint may take a long while to cool off. I have been known to put a cold-water-soaked rag around neighboring joints if I am concerned I am soldering too close to something I want to remain intact.

[Tubajug]

I agree about putting a small piece of solder under the middle of a brace, instead of just hitting it at the perimeter. I save all the "scraps" or excess blobs that flake off and use them for that purpose; they are usually flat already.

I love this idea! Thanks guys! Great help!

[Rick F]

I don't do much soldering of brass, but in my 30+ years of working in electronics, we always used rosin core solder. The rosin in the solder helps the solder flow more evenly. We also used flux, but the rosin helped.

[Donn]

The solder really should flow in to fill the joint, if you do it like TubaTinker describes above. I can see the attraction of the solder sandwich idea, but having the work wired firmly in place when the solder melts also sounds good.

[TubaOrpheus]

Thanks for all the advice! I went ahead and just took it to the local shop after talking it over with some friends and directors I trust. I do want to work on my horn in the future so I may buy a cheap horn and practice on it before working on my main horn.

[Tubajug]

Good plan. I did that with this little guy that I got for $50 on craigslist. I learned quite a lot from taking it apart and getting it all back together again. Good luck!

[timothy42b]

Two things to remember:
1. Do some practice on scrap pieces first. Buy some copper pipe fittings from the local home improvement store and make some art work. This isn't rocket science.
2. Even more important: hot metal is the SAME color as cold. Just saying.

Oh, I guess there's a third thing. If you mess up a solder joint too badly and have to take it in, the tech will roll his eyes and charge you 10% more. But if you fix it with JBWeld instead, well, don't expect to take it back to that tech ever again, if he'll even let you in the shop.

[TubaOrpheus]

Picked my horn up from the shop today and they actually did about twice the amount of soldering that I asked and was quoted (but was still just charged the original amount since I know the owner of the shop). She plays like new and has never been in better shape!

[jeopardymaster]

Nice Gnagey.

[TubaOrpheus]

Thanks for the compliments on my horn and the advice, guys!

Yeah I'm really happy with how the repairs worked out. They added some supports where there were none to begin with in addition to the braces I had them solder so it's much more structurally solid. They also rebuilt one of the braces to provide more strength. They even replaced one of the zipper pulls on my gig bag for no extra charge!

If you're ever in Arkansas and need your horn worked on, go to Independent Music Service just outside of Little Rock!

[roweenie]

I always associated tinning with soldering electrical wire, along with the use of a soldering iron.

As to your other question, I don't have any experience with that method.

When I solder, I like to put a small amount of paste flux (RubyFluid to be exact) on the tip of the solder, then I heat up the work just enough so that when I drop the flux onto it, it flows and gets drawn into the joint.

Once the flux is drawn in, then I know the work is hot enough to make the solder flow. Also, it's important to do your best to heat the the work all around, as evenly as possible - that will also help the solder to flow better.

Also, try not to over-heat the work to the point that the flux burns.

Most important of all, cleanliness is the most important thing - the solder won't flow over a dirty joint.

[roweenie]

Mark, what is the gauge of the solder you're using? It looks a little thick.

You want to use a fairly thin gauge 60/40 lead solder. Ferree's sells it in .062 gauge, which is nice and thin.

http://www.ferreestools.com/soldering/solder-flux.html" target="_blank

I get RubyFluid paste flux from Franklin Art Glass - one of the best repairmen in the country uses this flux as his favorite, and if it's good enough for him, it's good enough for me..

http://www.franklinartglass.com/shop/it ... 8-oz/3564/" target="_blank

[roweenie]

I had a hard time finding thin 60/40. I didn't think of trying Ferree's. If this doesn't work, I'll give them a look

Yes! They are a great resource for soldering stuff. They also have a "low-heat" silver solder that works very well, and soldering clips as well:

https://www.ferreestoolsinc.com/product ... 1091536152" target="_blank

[The Big Ben]

I don't do much soldering of brass, but in my 30+ years of working in electronics, we always used rosin core solder. The rosin in the solder helps the solder flow more evenly. We also used flux, but the rosin helped.

Rosin core is used in electronic applications because a certain amount of the flux always stays behind. The alternative of acid core solder is not used because as the piece of electronics ages, the acid will eat away at the wires of the joint and cause it to fail. There is a well-known (among camera repair techs) fault in the Olympus OM-1 SLR camera where the wire which connects the battery wire to the meter switch frequently breaks two or three years into the life of the camera. On this camera, if the meter does not work, this is the first place the tech looks. The fault was traced back to the factory and it was discovered that acid core solder had been used for a period of time. So, don't use acid core solder for electronic work. There isn't any reason for not using rosin core solder for instrument repair. Making a little solder donut to put beneath the brace would need pretty small solder. Using rosin core solder marketed for electronic work for instrument repair would get pretty expensive because, even in large sizes, it is pretty thin and it would take a lot of it to properly fill a joint between tuba bows or some of the larger braces. Solid solder can be purchased in a wide variety of sizes and metal composition.

Acid core solder used to be used for plumbing work but I haven't seen it available in hardware stores for quite awhile. Today, copper plumbing seems to be soldered with solid solder and brush-on liquid or paste flux. I have no experience using acid core solder for large brass fabrication. I did work in a shop that did leaded glass fabrication and repair and the techs used solid solder, paste flux and either a small torch or a large electric soldering iron.