Allowance for Soldering

Go down to your local hardware store and ball park based on the slip fit of copper sweat fittings.

Or just press it in if that's a strong enough junction.

I would try an 1/8" drill first. The ideal clearance is likely to be about as much as the drill makes the hole oversized. Tin the wire first and if it fits in the hole it should work.

-jim

I am not sure about regular solder, but silver solder ( the real stuff, not the stuff with a small percentage of silver ) has the most strength with about .0015 clearance. So I would also use an 1/8 inch drill, but would not tin the wire first. Just use some flux on it. If the hole has to be slightly larger, use a tapered reamer as Harbor Freight item 66936.

Dan

Shockingly small font but has some quantitative info:

"Good fit in joint clearances. The integrity of the silver solder joint depends on successful capillary action - the process by which the filler metal at flow/ liquidus temperature is drawn through the entire joint by the uniform clearances between the components being bonded. The strength of the completed joint is directly related to the space between the two components. For example, a silver soldered joint created with a joint clearance of .04mm can have a tensile strength exceeding 130,000 psi. This same joint created with a joint clearance of .5 mm will result in a tensile strength of less than 30,000 psi. Maintaining .04-.06 mm joint clearances creates optimum strength joints. Besides joint clearance, capillary action is also affected by surface finish of the components being bonded. Unlike "soft" soldering, a mechanical metallurgical action happens between the components being bonded and the silver filler material. The filler at flow temperature actually permeates the surface of the components and creates a mechanical "grip". If the material we are bonding is highly polished (like wire and crowns), the surface is more resistant to this flow and grip, and the metallurgical bond is weakened."

I did not find anything on ideal clearances with soft solder, but did find some info on strengths of soft solders. The 5% silver 95% tin is definitely the strongest of commonly available solders.

Dan

SWAG: 1/2 an RCH. Wick, don't fill.

Ooh, too big, methinks. Especially because drilled holes are usually a bit larger than the drill bit diameter due to runout, etc. A larger hole permits the solder to take the stresses, but you'd probably rather have the wire and brass dingus take it. Smaller is better.

-- In an industrial society which confuses work and productivity, the necessity of producing has always been an enemy of the desire to create. -- Raoul Vaneigem

Heh. I forgot to mention -- the music wire I have seems to all be oversize. Incidentally, by about the amount that a drill is oversize. So when I'm lucky I get a press fit (maybe light, maybe hard). When I'm not lucky I get a sliding fit or worse a "this won't go in for love or money" fit.

I'll try drilling with 1/8, then drill out bigger if that won't work.

If the music wire will not fit in the hole drilled with a 1/8 inch drill, try wobbling the drill to make the hole slightly larger. I might not do that in steel, but should work in brass.

Dan

I would try #30 (0.1285") Gerry :-)} London, Canada

Didja read the treatise on silver soldering posted by someone else? (sorry, I forgot already)

-- In an industrial society which confuses work and productivity, the necessity of producing has always been an enemy of the desire to create. -- Raoul Vaneigem

If the wire were not bent, 1/8" drill. The drill bits typically drill a little oversized anyway.

However, the wire will probably get a little wider at the bend, and I would measure there with a micrometer to check what hole to drill.

What kind of solder are you planning to use?

I don't think that lead/tin solder will stick very well to music wire. Try a bit and see whether you can get it to melt, flow, and stick.

And silver solder, which would do very well at sticking (and which needs perhaps 0.001" clearance for the solder to flow) might produce problems at the temperatures which it needs -- both in annealing the music wire, and perhaps oxidizing the brass -- you'll certainly have to polish it all after the soldering.

Good Luck, DoN.