Herschede Cracked Tubes

[010008]

Hello All,

I have seen a number of repair tips dealing with clamps, drilling holes at the lead of the crack to mitigate further cracking, plugging a drilled hole with brass, etc.

Just wondering if anyone has tried repairing tubes using a skilled welder. My thought would be to first drill a hole at the lead end of the crack then weld the entire crack with a TIG. I assume the tone would change slightly but maybe minimal? I will be talking with a welder tomorrow about his ideas as well.

Thanks as always in advance,
Dave Stewart

 

[Steven Thornberry]

I've moved this to the Clock Repair forum for better exposure.

 

[Willie X]

That will be dicey. I guess you could practice on some under the sink plumbing fittings. 1 1/4" plain and chrome plated brass tubing is readily available.

I just drill a 1/8" hole 1/8" from the end of the crack. I've never tried to repair a cracked tube. Course, I'm firmly in the 'leave well enough alone' camp.

Please report back, Willie X

 

[Dick Feldman]

I agree with Willie.
I have a set of tubes which are now junk because an amateur tried to save a few dollars. The welder tried to braze 3 tubes with gas and brass rod. There was no warranty to the clock owner.
Because of the scarcity of those tubes, it might be to your advantage to check a specialty welder rather than simply someone with a TIG machine.
There are newer advances in that field and a specialty jeweler or a concern that regularly repairs plastic injection molds might be a better choice.
Those tubes will require a high degree of expertise as well as high tech equipment.
A failure on one tube will result in the loss of the entire set of 9 tubes.
JMHO,
Dick

 

[Dick Feldman]

My experience is that if one tube in a Herschede set cracks, it will not be long before another follows. This is a common problem with those tubes. It might be to your advantage to try to replace the Herschede tubes with a set of tubes made for European manufactured movements. Those are much less prone to cracking.
A new set those tubes may be available through Black Forest Imports.
This board is populated by all levels of clock repair people. I would caution you that you may receive poor advice here.
Dick

 

[Willie X]

If your welder has a bunch of beautiful fillet brazed bicycle and motorcycle frames hanging around everywhere. That will be a good sign.

And, keep in mind, you will be altering the tube which will change the sound, for better or worse.

Willie X

 

[wow]

I like the drilling idea also, however, it is not necessary to drill the hole much larger than the crack width to stop the crack. The more material removed, the more affect it will have on the change in pitch of the tube. So I think it should be a tiny drill bit.

 

[Dave Diel]

I did a little research and found a page written by a guy that has TIG welded brass:

"The reason tig welding brass is difficult is because of the zinc. Zinc has a really low melting point.

Combine that with the fact that brass is very thermally conductive and requires quite a bit of heat input to weld, and you have an arc that tries to vaporize the zinc. When the zinc boils, it likes to jump on your electrode and you have to stop , grind the tungsten, and start again."

Breathing the vaporized zinc is a big problem. If the tubes are chrome plated, the vaporized chrome is even more of a problem because it is carcinogenic.

Here's the full article

Please let us know how it goes.

 

[dickstorer]

In post number 4, I think Mr. Feldman is referring to laser welding. Laser welding can be used very successfully for this application because there is very little heat generated, thus no distortion. Drilling a tiny hole at the end of the crack is very important to keep the crack from growing. Laser welding works with chime rods with no sound distortion bad enough to keep from using it.
In post 7 Mr. WOW also suggests a small bit. A number 60 is usually small enough.

 

[010008]

Well, Thanks for all the comments. I spoke with my welder guy today. He does do good work but knows his limitations. Looking at the crack he pointed out that it appears to be brass below the shining surface. He did know about the zinc issue with brass. Basically, when welding, it almost looks like it's working then it's gone in a puddle of sludge. I give him a lot of credit both for knowledge and honesty. His main point was he would try one tube but would make no guarantees and stop at one if there were "issues".

I do know a Jeweler that has a laser welder. Not sure he would be willing to give it a go, but I will check.

Dickstorer, it sounds like you have tried this? Laser welding does produce a lot less heat. This is why jewelers use it (if they can afford the setup).

I'll update with any new information.

Thanks again for everyone's input.
Dave Stewart

 

[Willie X]

To do something like this, one has to do it on a regular basis. Willie X

 

[Peter John]

I have been in this business for almost 60 years. I have repaired dozens of tubular chime clocks of various manufacturer. Cracked tubes are a problem occasionally. Frankly I have NEVER drilled a hole at the end of the crack. I have also NEVER tried to weld a crack. That will surely ruin the sound. While drilling a hole may stop the crack from progressing I don’t recall a problem with any of the clocks becoming a problem with tubes that have continued to crack. Sometimes people can make a real problem out of a problem that will not get worse in our lifetime. I’m with Willie, sometimes it’s best to leave well enough alone. I may get flamed over this comment but that’s my opinion and I’m sticking with it . Peter

 

[Willie X]

I do the hole thing and I am a professional metal worker but I only see a few of these in a year. Lately maybe none in a year! I like you, have never seen this to be a big problem. The tube bells look great but actually never sounded that good to me.

I love me some big German gongs.

Willie X

 

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