Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Is this Schumann Upright bass bridge Salvageable?

The bass bridge was badly cracked, to where the top of the bridge was lifting or peeling off:

[img:left]https://flic.kr/p/pbYLmG[/img]
[img:left]https://flic.kr/p/pbJWfX[/img]
[img:left]https://flic.kr/p/pbJWfX[/img]

Pretty hopeless, right? Unless I was a rebuilder, which I'm
not!

I'm not past doing a Micky Mouse fix on this: Do you think it's
possible to loosen the strings, and grey epoxy this bridge and the pins back together? Or does this one require re-building the bass bridge entirely?

This bridge is too far gone. The effort that it would take to salvage it would be better spent replacing it. Why would you consider ever doing a Mickey Mouse fix on anything? It's never worth it.
Tim

If you loosen the strings, then the bridge cap may fall off anyway by itself. Then you could have the exercise of re-capping it. Micky Mouse could do that!

They shoot horses, don't they?

So do you think it might hold a tune for at least a few
years? With a grey epoxy (or JB Weld?!?) repair?

Doesn't look hopeful to me....

Dust damage.





HW

Sure. The piano will play in some fashion indefinitely with or without any repair. The question really should be, "Will the piano sound decent without any repair?" And the answer to that, of course, is "No."

This type of repair is usually not all that difficult. It will involve loosening the bass strings, unhooking them and getting them out of the way, removing the cap (which is pretty much falling off anyway) and gluing it all back together.

JB Weld is entirely inappropriate for this type of repair but any decent wood adhesive such as Titebond II should do just fine once the old glue is cleaned away.

These types of repairs are fairly basic; Piano Technology 101. Most any local technician should be able to help you do the job properly. After which, assuming the rest of the piano is up to it, the piano will play just fine. (While you're in there you might clean it up some....)

ddf

Thanks Del.

From what I have gleaned from the web, grey epoxy would
work in this situation. I have also heard someone recommending
CA glue in this case.... what do you think?

Ok, I'm still a bit indecisive about this, because the ivory white keys are a bit ugly and mismatched, and I don't really want to replace all the white keytops. But it's possible the ugliness was also due to the keytops being very unlevel, which is fixable of course. There were a few chipped keys in the lower bass notes. Is it illegal to buy ivory keytops on Ebay? I would assume so.

So I still may pick this bad boy up!

Well, I think I said JB weld -- which is, I think, what you are referring to -- is "inappropriate for this kind of repair". That means, no, JB Weld would not be an appropriate adhesive for this kind of repair. I'll add to that that CA adhesives are also inappropriate for this kind of repair.

If you want the repair to hold for a reasonable amount of time the two pieces -- the cap and the body -- must be separated, cleaned, reassembled and clamped back together with an appropriate adhesive such as Titebond II. There is a fairly standard procedure for this kind of repair. If you don't want to consult with a local technician then at least buy (or borrow from the library) Reblitz's book on piano repair. It's been several decades since I've looked at it but I'll bet there is a section in there on bridge repairs.




If this is a piano you want to learn or practice various repair procedures on then it is also worth doing a little study to make sure those repairs actually do the piano some good. Poorly done and inappropriate repairs have ruined many an otherwise salvageable piano.

ddf

Old piano repair 101... Learn how to fix everything. Keytops are no more difficult than bridge repair. Different glue though.

Hmmm. You also have to consider whether the bass bridge has any bearing left. It appears that the bridge may be coming apart because the strings are lifting the bridge cap right off the bridge itself.

Lashing it together may work for a time...but you may need to add a little more height to the bridge while you are in there anyway.

Or.....a less compromised piano to own!

Unless you want to learn about fixing pianos I can see no reason why you would do this. It is never going to be worth the cost of doing the job.

Get the Reblitz book as suggested and learn to do a bridge repair the standard way. Great learning experience.

I have the Reblitz book, and on page 93, it recommends using epoxy to repair bridges.

This makes sense, because the reason guitar luthiers do
not typically use epoxy is because it's stronger than the
wood, and makes dis-assembly at a later date difficult or
impossible.

But in this case, it makes sense to make the glue stronger
than the wood.

To Philip: Yes, I mainly want to do this just to learn, and
have FUN!!!

Page 93 of the Reblitz book refers specifically to using epoxy to fill small splits around the bridge pins, not to repairing a broken bridge cap. Your bridge appears to be damaged beyond what Reblitz recommends for repair on Page 93. See pages 132/133 for more.

Properly made and epoxy repair can be effective. Stuffing JB Weld in there is not going to be a properly made repair. It is very thick and it will be virtually impossible to get the stuff fully into the void. Even using a more appropriate epoxy will be problematic. Epoxy bonds well to most substrates. In this case you'll be doing a great job of bonding the epoxy to the accumulation of dirt and old glue coating the wood. If you want it to bond to wood you first have to get to the wood.

This bridge has other problems. It represents massive glue failure. Fixing the obvious separation does nothing to stop the rest of the adhesive bond from also failing. It also appears to me to have other problems with string bearing -- why is the gap so large? -- along with a few other issues.

But, please, do make whatever repair you think is acceptable. It's your piano you're free to do whatever you want to do with it. If you subsequently try to sell the piano just don't try to pass off a patch up job -- at best -- as a competent, workman like repair.

ddf

From page 133:

"Split Treble Bridge cap: Repair with epoxy; or, if badly split, replace the cap. If a single piece of treble bridge is split so badly that it cannot be repaired with epoxy, the entire bridge must be removed and duplicated. Make every attempt to repair the old bridge with epoxy before attempting to remove it."


Since I don't have the skills to duplicate this bridge,
I would fix it with epoxy.

I still haven't bought the piano yet....still deciding...

To Del: If I sold it again, I would explain this was a learning
piano...

If this is a learning piano, why not learn something from it? From the pictures I'd say you wouldn't need to build a whole new cap. The original cap is already half off and getting the rest loosened shouldn't be difficult. Then it is just a matter of cleaning off the old glue and reattaching the thing. Clamping can be accomplished by (neatly) drilling a few holes through the cap and using screws (with washers) to apply clamping pressure. When the glue has dried pull the screws and put in some small dowels. Clean it all up neatly and you're done.

ddf

Ok, good idea on the clamping.

Reblitz warns that loosening more than 6-8 strings
puts the plate in danger of cracking. Maybe I could do a small
section of the bridge at a time? Or maybe slacken every other string in the middle octaves?

Also, how much do you think this old Schumann upright weighs? My piano dolly is rated for 800 lbs.

Nope. The bridge cap has to come all the way off to work the cap off. And that means the bass strings need to be fully loose and moved out of the way.

It is highly unlikely that the string frame will crack when the bass strings are loosened. Piano technicians worldwide have been doing this for decades without such catastrophes. It is certainly a possibility if the casting is particularly weak or badly designed but it is a very remote one.

With experience you'll learn to recognize string frames that appear potentially weak. In the mean time, if you're really concerned about this drop pitch by a half-step or so before you remove the bass strings.



Can't make a reasonable guess without actually seeing the piano. Almost certainly less than 800 lbs., though.

ddf