Cracked tailpiece repair?

[Geno]

The Waverly Cloud tailpiece on my '25 A-Jr is starting to crack at the bend. Is there a good way to repair this that will last a few more decades? Is this something a jeweler would be able to fix? I've been looking for a replacement for a little while, but haven't found one. I don't want to put on a non-original type replacement.

[Paul Hostetter]

This is a simple one. You extend the broken hook. This takes a jeweler's saw and the skill to wield it, and a cautious bending up of the new prong. Assess that prospect carefully first.

http://www.lutherie.net/mandolin.tpc.clam.repair.jpg

If the missing hook is obstructed by a screw, either use the screw itself to hold the string loop, or put a second small screw (carefully!) into the place where the hook broke off.

http://www.lutherie.net/mandolin.tpc.clam.repair2.jpg

Otherwise, start haunting eBay for a replacement. They do show up there.

[sunburst]

Looks to me like all the hooks are in good shape in the OP's picture.

There's no tension or stress on the crack from string pull, and I'm not really sure what caused it to crack there. It's as if the radius of the tailpiece is too small to fit the end of the mandolin so it split from "trying to" straighten because of pressure from the strings. If the strings aren't breaking where they cross the crack, I don't think it will be a problem, especially with a cover keeping it out of sight.

[Jean Fugal]

I would be inclined to "stop drill" the crack between the 7th and 6th strings smooth up any rough edges and then hide and watch for a spell.

[fishtownmike]

Take it off and bend back into position and solder the seem with electrical solder and a soldering iron. Then file it down a little to smooth it out.

[Paul Hostetter]

OK, I just saw what was really going on, it has nothing whatsoever to do with the hooks. My apologies for jumping to the solution for the most common problem those tailpieces have, because it's something else entirely.

I agree with John: there's really no problem there. A mystery crack, possibly because the stamped radius of the fold in the tailpiece never really matched the radius of the edge of the mandolin, and 85 years of string tension finally made it give a little. This could remain exactly as it is for another 85 years. Even if it moved a little more, there's no harm being done, no structural consideration being breached. I'd put the cover back on and forget about it.

Solder would be completely ineffectual in a case like this, especially electrical solder. I suppose you could fill the crack with lead solder, but it would amount to little more than spackle. It has no strength.

Even silver solder (beside the fact that applying it it would ruin the plating) would be insufficient to stabilize a crack with that much string tension pulling on it. It would simply reopen immediately.

But...if it had been a hook cracking, why drill a hole between the 6th and 7th when the problem is on the first string prong?

[Jean Fugal]

It looked to me like the crack was/is almost to go under the 7th string. A small hole in line with the cracks path will stop the crack from going any farther. A common repair on aircraft in non-critical (not safety of flight) cracks

[Paul Hostetter]

It looked to me like the crack was/is almost to go under the 7th string. A small hole in line with the crack's path will stop the crack from going any farther. A common repair on aircraft in non-critical (not safety of flight) cracks

OK, I see now what you were talking about. I was still on the broken hook detour. I understand the concept of the hole ahead of a crack, but I have a hunch that crack is about done doing all it's going to do.

I also think we count the strings from opposite directions. To me the Es are 1 and 2, and the Gs are 7 and 8.

[Geno]

Thanks for all the help. It has not been causing any buzzing or breaking strings. Heck, I have no idea how long its even been there, I may have just not noticed it before. I think I may try the "stop drill" and try to snatch up a spare, if I ever find one.

[Rick Lindstrom]

I'm with Paul- put the cover back on and forget about it. It just doesn't look like it's structurally significant. Trying to drill it might just make it worse.

Rick

[Geno]

After closer examination, the crack actually goes all the way to the 3rd string, you just can't see it in the picture. I don't think it would hold up long if I made it worse, so I won't risk it. I 'll find another one eventually. This old snakehead just sounds so great and plays so well, I gotta keep it running.

[mandroid]

Perhaps a benefit of a smooth bend for the string to pass over the edge, and the crack where the flange-bend is could be filled in with solder , regular rosin core electrical solder, should do , clean and flux the metal so It will stick., smooth as needed .

The covers seem to go missing a lot , so somebody must have removed the whole thing , to have a complete TP, you could seek a replacement base from the classifieds audience.

[Steevarino]

I hate to disagree with Paul (especially since he recently placed a nice order with me:)) but, through the years, I have silver soldered quite a few tailpieces that have failed in this same way. True, electrical solder will be about as helpful as bubble-gum, but silver solder seems to be pretty strong. It is often how I affix the ends to my truss rods, which have to endure quite a bit of torque, so I know it has pretty good holding power. On a crack such as this, I usually float a liberal amount of SS in on both sides of the crack, file it down smooth, etc.

Paul is right about his comment about the plating, the heat from the torch will mess it up. I can usually clean it up pretty good, as the parts usually look fairly old and weathered anyway. Oh yeah, I also add the disclaimer that your coveted part just may end up being a blob of molten metal on my shop floor. Hasn't happened yet, but you never know...

[Paul Hostetter]

I hate to disagree with Paul (especially since he recently placed a nice order with me:)) but, through the years, I have silver soldered quite a few tailpieces that have failed in this same way.

Dat's what I said, so you're not disagreeing at all! Silver-soldering is about as strong a braze as one can get, but pushing that tear in the tailpiece back into shape and silver soldering it probably won't last. National tailpieces are another one that has a rather high re-failure rate. The original metal couldn't take it, I doubt the braze will help. I suppose one could braze a patch over and across it, but I don't see the point, under the circumstances. I doubt it's going to get appreciably worse and it doesn't pose any practical problem.

[8ch(pl)]

I would consider using an epoxy-metal paste. Shape a piece of hardwood to fit inside the radius, put waxed paper between the wood and the tailpiece, mix up some epoxy-metal and slip it into the crack. Don't use too much, sand, or file off the excess.

The hole in the end of the crack will work in conjunction with the epoxy-metal. The area should be sanded to give it a little tooth. a little bit of overlap on the inside and the outside will add strength. It should be hidden by the cover.

Devcon makes the Epoxy-metal paste, there are others as well.

[Paul Hostetter]

I would consider using an epoxy-metal paste.

What would it accomplish that simply leaving it alone wouldn't do just as well? Electrician's solder would be like spackle, epoxy would be like spackle. It's under the tailpiece cover where you can't see it. What's the point?

[John Morton]

Silver solder should be as strong as the parent material, but with any solder you should be sure to add a radiused fillet on the inside, and not simply fill the crack. It is true that the temperature (1200 deg. +) will mess up the plating.

I have repaired some guitar trapeze tailpieces and some Nationals by soft-soldering a dihedral corner of brass to the inside, visible only as a thicker edge. You can tin the piece and sweat it on from underneath, which might spare the plating. You can get low-temp solders for this sort of work, maybe 350 deg. or so. If you bevel the underside of the splint on the sides, it will be inconspicuous.

John

[s1m0n]

I'd laminate the back of the entire tailpiece with thin sheet stock, and then file most of it off again. Leave the full thickness under the crack and it can take the strain for the next 85 years.

[pops1]

Drill the small stop hole and forget it. The hole will help and can't hurt anything.

[Darryl Wolfe]

I am reading with interest as I have two vintage Dobro mandolins of which their bent one-piece tailpiece now are two-piece versions

I plan to braze them and file clean as well as I can and simply accept that they will be a tad ugly.

I would leave the OP tailpiece alone

[mandroid]

From the location of the crack, I wonder if it was forced to follow a tighter radius than the stamping die produced, the fatigue and the work-hardened fold cracked.

Ugly is reduced by having the cover back in place. ;)

asking the community with lost covers that have replaced the base on theirs , for their base, is a sure cure..

Note , silver solder won't fill that gap, , so you need to bend the base back to what it was so the seam of the crack is back to a hairline. Plating will be toast. metal will need to be Orange hot to be at the melting point of silver solder ..

JB Weld OTOH is a cold patch. :popcorn:

[Rob Grant]

Repair... why bother? Either leave it the way it is if you're afraid of messin' with the value of the instrument or bend up a new one from stainless steel or brass. This is not a "complicated" t.p. by any means.

[MikeEdgerton]

There really are people that have these tailpieces stuffed away, you just have to be willing to pay the price.

[David Collins]

The goldsmiths upstairs from my shop have a Rofin laser welder, which in the right hands can do things you couldn't dream of with traditional solder or brazing. I've had them repair a few similar pieces for me in the past, and it truly is an incredible tool. This thing can damn near work miracles.

I've practiced on it a bit myself, but it certainly takes some experience with it to really nail a perfect seam, which can be done without affecting anything beyond the immediate area, no scaling, and very little cleanup needed if done well, so I typically just pay them to take care of repairs like this.

This is honestly more of a distraction to them than anything, as they of course are busy with their own jewelry, so I'm not inviting anyone to send their cracked tailpieces to me. I have access to it to use myself whenever they're not using it, but I'm not personally ready to take any jobs like this in until I have some more time to properly train on it. Still, it may be worth calling around to jewelers in your area to see if any of them have the capabilities of doing this cleanly. If they have a laser welder it can be repaired very solid, and with minimal visual effect on any plating or area surrounding the joint.

[8ch(pl)]

Epoxy-metal paste is considerably tougher and stronger than just epoxy. If it is on both sides of the tailpiece, the block of wood smooths out the inside, the compound is smoothe out with sandpaper on the outside and the crack is completely filled it would probably be as strong as the original. It can be drilled, tapped, machined etc., not that that is needed in this case. I have used the aluminum variety on numerous occasions, the steel filled stuff is even tougher.

It is very strong Spackle.

[slausonm]

I am a novice stringed instrument builder but I have close to 30 years experience on band instruments. I frequently make repairs to instrument keys as well as building keys from scratch. They are made from brass, nickle, and silver. The general means of afixing the pieces together is silver solder. I repair broken keys with silver solder and in many instances can make a cosmetically acceptable repair without needing to replate the key. IMO the crack in the tail piece can be repaired best with silver solder. I would disagree that the crack is not structural. Part of the reason for the 90 degree bend in the tailpiece at this point is to add support and structure to thebridge that counteracts some of the forces of the strings as well as a transition for the strings to rest against. I would not use soft/lead solder for the repair as it is more succeptable to fatigue and failure over time than the silver solder. I would not use the epoxy method as it is cosmetically unappealling and I don't believe it will have the strength of silver solder.
Like any soldering, the key to a good silver solder joint is good mechanical fit and clean, clean, clean, materials. Much less heat can be used by making sure the parts are cleaned first. Most bad solder jobs that destroy the finish of the surounding area are due to the need to over heat the parts because the person did not clean them well enough first. Solder will not flow to a dirty surface.

Lastly, if you haven't tried the touchup and electroless nickle plating kits from caswell, you should. I used one of the electroless kits on my home made tail pieces and they worked great. I've been using their gold and silver touchup kits for quite a while. I bet that tail piece could look and function like new again.

[Geno]

I am taking all of this in with great interest. There are quite a few ideas to consider from many knowledgeable people, but no real consensus. I did talk to a local guy with a Rofin laser welder today, but he has not seen it yet. I kind of wish somebody would say, "yeah, mine cracked just like that 20 years ago. I did this, and it's been fine ever since". The good news is, while I'm thinking about it, I can still play the #### out of the mandolin. Thanks again to everyone for your suggestions.