Broken Palm Key -- Help

[innerear]

I was repadding a promising Kohlert Winnenden ( SG Roo pads with Noyeks ) and everything was proceeding nicely until .... I was cleaning the F palm key pad cup with acetone ( I had done a preliminary pad installation without the resos just to see what it sounded like and had used a little contact cement to hold some pads in ) and while apparently grasping the key behind the arch, with just a slight amount of pressure , the key broke in two. After looking at it I realized that there was a ridiculously small amount of metal holding it together and that it was probably already weakened and only needed a small amount of force to rend it asunder. For some reason, instead of a solid piece of brass, half the arch ( over the E key ) was hollow, and there was maybe only a 32 of an inch of metal on either side holding it together.

So, my question is: how best to repair this, if possible. I've resoldered a few keyguards and posts, but nothing like this. What kind of solder will make the strongest repair. Thanks.

[Gordon (NZ)]

It should be "silver solder" for strength, i.e. approx 40 - 45% sliver.

This solder is not suitable, though, for much building uop, so it would be appropriate to add a piece of strengthening brass, also silver-soldered in.

[innerear]

OK, and forgive my inexperience, but is there any point in trying to resolder the metal surfaces together, or should I just try to build it up from the inside and/or the outside? Are you suggesting that I solder a strip(s) of brass across the break for strength? Probably no way to go about this without it being fairly noticeable, yes? As always, thanks.

[hornimus]

innerear, if you haven't yet learned silver soldering, don't "go live" with an irreplaceable sax key. There are so many things that can go wrong.

[innerear]

Yes, that sounds like sound advice. I'll try to restrain myself. If anyone would like to recommend someone for this kind of repair, I'd appreciate it. I live near Roanoke, Virginia (not that geographic location is that big a factor). Once again, thanks.

[hornimus]

I don't know your background, so anything I say is basically gratuitous.

The reason I voiced concern is that the parts must be flat and flush and very clean at their interfaces for silver-solder to flow and form a joint. The parts have to be heated red-hot, and if the joint(s) to be formed are near older, original joints (e.g., the keycup, the hinge tube, the keytouch), you may end up with many more pieces falling off than you started out with. Or you may overheat and roast out the zinc and destroy the brass.

If you know what you had and how you want it repaired, a local jeweler might even do it for you (and even better than some techs who are not as concerned about appearances).

You could also consider using a low-temp lead-free soft solder that's marketed sometimes as low-temp silver solder (94% tin/6% silver). This stuff fills spaces fairly well, doesn't need as smooth and flush an interface for the joint (although it helps), and will flow at temps comparable to soft solder, thus averting the risks I mentioned above. Plus, the created joint is about twice as strong as one made with regular lead-containing soft solders (but not as strong as silver-solder). Best of all, (IF the Kohlert key you want to fix is nickel or silver plated) it leaves a shiny silver luster, unlike the dull gray of lead solders, which means you could polish off any excess and still have a finish close to the original in appearance.

Having said all that, I reiterate: this ain't something you want to do as a "learning" experience. Better that you leave it to someone who's done it a few times.

[innerear]

That's very helpful. Maybe you shouldn't have given me all that info as now I'm thinking that maybe I could attempt this. Actually, I've since discovered that I lost one of the rods to another palm key, so the horn won't be playable any time soon. I'll need to replace or fabricate this too. Maybe I'll just try to score another one on eBay cheap, borrow the parts, and worry about fixing the new one later. Your suggestion to take it to a jeweler is a good one. While there is a definite derth of good instrument repair technicians in this area, we have an abundance of jewelers and craftspeople hereabouts. 'Ppreciate it.

[Gordon (NZ)]

Wind-mill is quite correct with his cautions. This work should be left for the experienced.

I would never use a tin/silver (95/5%) low-temp solder for such a location, because it is is nowhere near as strong as a 'silver- solder'. Silver-solder gives a result usually stronger than the original.

I am not sure about your Keilworth model, but some Keilworths were made in strange places, in which case the key COULD be made form 'muckmetal' ('pot-metal'), in which case silver-soldering cannot be done, and any other soldering will need significant and rather unsightly reinforcing - probably on either side of the key.

The reinforcing I mentioned before, only if it were needed for strength, would probably be on the underside of the key, and if done well, would be barely noticeable.

[hornimus]

Maybe you shouldn't have given me all that info as now I'm thinking that maybe I could attempt this.

Ah, but I didn't give you the whole picture. By the way, is the problem key nickel-plated?

[innerear]

Alright, I'm not going to mess with it -- for now. Like I said, the strange thing about this key is the small hollow section at the point where it broke, and in terms of repairing it that might be a good thing as one could fill it with solder to bridge both pieces.

This is a Kohlert, not a Kielwerth, though I guess in some cases the name is pretty much interchangable. I think I dated this one to 1949, and it seems to be very well made other than this (defect?). It's all lacquered brass (pot metal? don't think so, but how would you tell?). I just rebuilt one of the later Bixley models and it did have some problems which I think originated at the point of manufacture -- like posts not positioned quite right and a G# mechanism which I had to modify in order to get to work properly.

[innerear]

And that should be Keilwerth not Keilwerth. Thanks Gordon and Wind_mill.

[Gordon (NZ)]

Yes, I meant Kohlert when I wrote Kielworth, which should have been Keilwerth.

Both have some rather dodgy products.

I don't think I have ever encountered pot-metal that was not nickel plated when used for instrument keys, so you seem to be safe there. Pot-metal has quite a white appearance.

[Saxdaddy]

As Gordon has already said, a hig temp silver(braze) solder is the only way to go for broken keys, and unlike what was posted before, the parts don't have to be flat, or fit perfect to do this, but they must be clean. This is something that is best left to techs, as it is not very easy, and can be dangerous to repairer and horn alike.