How should I repair this piano bench?

[Alex Franke]

The back of our piano bench has been broken off by a very enthusiastic four year old. I'd rather not replace the whole board because I don't want to have to match the finish. I was thinking I would try to route down the broken parts like you would for a half-lap, glue in some hard maple, and refasten.

But that would put about all the stress on the glue joint... They say the glue is stronger than the wood, but I dunno... it just doesn't feel right.

Any thoughts?

[ironhat]

A glue joint will withstand repeated hammer blows if clamped and allowed to cure overnight. I tried it with simple, Elmer's glue many years ago. But, like you I would be hesitant. I've always thought that the tiny butt hinges on piano benches are inadequate. I would clamp and glue and then, use a piano/ continuous hinge for better distribution of stress.

[sparkeyjames]

I might go a step farther than ironhats suggestion. Remove screws from inside piece reglue and clamp let sit overnight. Don't forget to glue in both directions. Across the break and where the end meets the corner post. Do not clamp the down the length as this will only serve to misalign the split. Get some slightly larger longer screws. Redrill for slightly longer and larger screws. Try to keep the screw length 1/8 shy of exiting. This should give them good holding power. Put them in. If possible add more screws. This should do the trick. You got lucky in that the split is to the inside. Should look as good as new when your done.


Oh yes and something more I just thought of. Some of those brackets that limit the travel of the seat so it only goes up just past 90 degrees. If they are there sorry I don't see any evidence of them from your photos.

[Daryl]

The style of leg bracket pretty much guaranteed it would break like that.
Unless you add the hinge to the leg, using a piano hinge won't lessen the force on the broken part.

[gary]

Also, how about reversing the bench and mounting the lid on the opposite rail? That way most of the stress will be on the unbroken piece?

Does the broken piece fit in after removing the loose pieces? If it does, I'd consider repairing it with Epoxy and clamping it up.

[wardprobst]

Well, you got some decent advice but since I do this for a living I'll add my two cents. First, take off the bench lid, saving the hardware. Second, loosen the leg bolts and remove the legs. Use Titebond or Elmers to glue the pieces back together, clamp and let dry overnight. Be sure to pad the clamp if it's not already padded. Reinsert with original hardware- do not glue to the legs themselves, do not use longer, larger screws. Check tightness on the screws that hold the brackets. Set the bench on a flat surface, remount the legs and make sure there is no wobble. Reattach the lid and put a limit chain or string or bench lid prop on it. Don't put any load inside the bench they are made for very light storage. Make sure the bottom is firmly attached. Don't set the bench on unequal surfaces and you should be good to go.
DP

[Alex Franke]

Thanks for all the advice so far. Nice to hear from a piano expert, wardprobst! (How come I can't find anyone who will tune a piano by ear anymore like my Uncle Hans used to? )

I have a monkey wrench to throw into the mix. I loosened the leg hardware and removed the screws and the broken parts fell in pieces. I also noticed that one side had been previously broken and apparently not-so-expertly repaired -- there's glue drizzled on both sides in the break.

I don't know if I'll be able to remove that glue without damaging the mating surfaces and compromising the integrity of the joint...

Here are a couple more pictures that illustrate this more clearly. One break on the left is along the screw hole. The image on the right shows the glue.



Gary, I like the "turn the bench around" idea -- I might just have to do that. I can get felt pads to cover up where the hinges were so it doesn't look so obvious. . . .and maybe attach a 90-degree stop to help prevent the same problem in the future.

[ironhat]

I believe there was a recent post which mentioned loosening this type of glue with an iron. If you don't get any response more knowledgeable than mine (not saying a lot, I guess) then I would only do this after a trial of your own.

Re: the wardprobst comment... Limit chain!! Of course... Ooooooo, I was soooo close - or maybe not so much - LOL!!


Addendum: Take a minute and go to the www.wardprobst.com and look at the terrific restorations that those folks do. They are truely "craftsmen".

[wardprobst]

Alex,
Go to http://www.ptg.org/findATechnician.php to find an aural technician. Realize also that many of the electronic tuning devices out there are used by technicians as aids- the ear is the judge. The ETD is like a power tool for most of us, gets you in the ball park.
You can remove the old glue with heat most likely, if that doesn't work call a technician it will be better than messing up a bench that might cost a couple of hundred dollars to replace.
DP

PS Thanks for the compliment Ironhat

[pierhogunn]

I read in the past about using hot white vineager to loosen wood glue

[wardprobst]

I read in the past about using hot white vineager to loosen wood glue

That will work but there is a danger of swelling the wood and possibly damaging the finish. I'd remove as much as you can mechanically, then try to heat soften and remove the rest. It's not much fun to redo another person's repair. We do it all the time which is why we get the big bucks~!

[Alex Franke]

That will work but there is a danger of swelling the wood and possibly damaging the finish. I'd remove as much as you can mechanically, then try to heat soften and remove the rest. It's not much fun to redo another person's repair. We do it all the time which is why we get the big bucks~!

Well, I got most of it off with with a chisel -- it was very rubbery actually, so it's not the kind of glue I'm used to. I tried heat to remove the rest, but I think there's still too much space between the mating pieces for a strong glue-up.

So at least for that side I'm back to thinking the best way to repair it is to plane down past the break, glue in a new bock of wood, and then trim it flush... or maybe I can try the re-glue and just mount the lid onto the other rail so it doesn't get as much stress... hmm... I'll sleep on it.

[JSUPreston]

Okay, crazy idea, but I gotta say it...

What about using a new piece of wood on the backside, and taking the existing wood and using it as a veneer? Something strong. I think poplar or another hardwood might do it.

I would think by doing so, you would eliminate the weak points of a glued joint, and from the outside still retain the original look. Yeah, if you open the lid you'd see the difference, but how often is the lid opened?

[Alex Franke]

Okay, crazy idea, but I gotta say it...

What about using a new piece of wood on the backside, and taking the existing wood and using it as a veneer? Something strong. I think poplar or another hardwood might do it.

I would think by doing so, you would eliminate the weak points of a glued joint, and from the outside still retain the original look. Yeah, if you open the lid you'd see the difference, but how often is the lid opened?

Ooo -- I like this idea!

I can cut a thin strip off the face of the board with the band saw, but then how would I clean it up? I guess attach it to a backer board and run it over the jointer?

[LCHIEN]

JSUP's idea was good.
I'd use a scrificial push block and run it over the table saw, make the offcut the thin strip. Then it would be more or less ready to attach without a lot of further cleanup.