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The PTG sourcebook describes very little. I'm referring to 'repairing' a broken shank, not 'replacing'.

How to use cut the ends of the shanks and glue them together yet still maintain a straight line ?

There is no good way to do this. Replacement is the best option. I have had too many of these "repairs" fall apart to recommend anything else.

Depends on the line of breakage. If it´s elongate it´s okay to glue it because you will have a great enough surface for the glue. Otherwise just replace it. If it´s not really broken into two parts take it and break it into two parts. If you are lucky you will get an elongate line of breakage. Is it an upright? In field service I ask the customer to use his cooker for heating the glue joints. After heating you can easily pull out the shank from butt and hammer. For cutting the new shank to the correct lenght I use this tool:

http://www.meyne-klaviertechnik.de/...ails&id=438&code=0&zustand=1

good luck

Gregor

Cut a length of plastic drinking straw to make a sleeve. Glue the pieces of hammershank together and slip the sleeve over the joint. The way to do this is to simply slide the sleeve onto one piece of the broken shank. After the glue is applied, move the sleeve into position over the repair. Use Titebond or other white glue. Try to set it as straight as possible. Screw the repaired shank back onto the action rail and align it with the hammers on either side, using them as guides.

Cashley - As the others have said, whether you can do this successfully or not depends on if it's a long break or a stubby one.

This method has always worked for me on long breaks. I use Titebond on one of the two surfaces, then fit the two halves of the shank together. Then I hold the shank with my left hand at the very end of the break so that the length of the split is to the right of my hand.

With your right hand holding a spool of upholstery thread, take the end of the thread between your front teeth and pull out about a foot length. Wrap it around the broken shank near the spot at which you're holding onto it with your left hand. Then start wrapping neatly (and tightly) with about 1/8" in between the wrappings. When you get to the end of the split, double back over the original wrappings.

When you're back to the beginning, hold the two ends together, cut about a foot off from the spool, and tie and knot the beginning length to the end length. (That's the only tricky part to the operation.)

I make sure the alignment is right (you can do a little adjusting) and then I smear a little glue over the whole works, and let it dry. The thread stays on the shank. The glue prevents it from ever unraveling.

This really works well. In doing this over 30 years of servicing pianos, I've never had a shank thus repaired rebreak.

I'll take some pictures next time I do this, and write a short article to go onto the Schaff website. It's always easier to explain things when you have pictures to work with. Chuck

If its broken off as a stub at the hammer or butt, you can drill it out using a head and butt boring jig. You use the hammer next to it to set the angle on the jig, then drill it out.

A second method for removing stubs is to soak the stub with wall paper remover, drill a small hole down the middle of the stub, then screw in a drywall screw. You can then use a puller to pull out the stub.

If its an elongated split you can use the thread method or the supply houses sell shank sleeves. Wendys' straws use to be perfect, but they changed the size.

You should practice the replacement. You'll need it for the RPT test, anyway.

--Cy--

I vote for replacement as well. Not to get on the RPT bandwagon too much, the thing of most value I got from the test process was the learning of this type of repair. You go over it enough to do it in your sleep, blind, drunk, whatever, or you don't pass the test.

I'd order a bunch of parts to use as guinea pigs, or find a dealer willing to scrape out the parts box and give you some good practice materials.

Many thanks...

I'm not saying replacement is no good. The question is about repair per se.

Now if the shank is broken, one end is attached to the hammer, the other the butt. Lets make some assumptions and work within the parameters.

Lets assume that for some reason it's not advisable to extract the broken shank from the butt. We cut a new shank and glue it to the shank that is attached to the butt. This is the crux of my question.

We need to re-size the joints so that both have a large surface area for glue. I guess we need a knife and a sand paper. The problem is when re-sizing the joints, is there any technique that will ensure that when the joints are joined together, the end product is straight ?

What if the inside diameter of the straw is much greater than the diameter of the shank ? What purpose does the straw sleeve serve it's not glued to the shank ?

Can the cutter cut an elongate surface ? Or strictly perpendicular to the shank ?

The method I was shown by a technician was to use a new hammer shank, cut it into halves, and use one end to join it to the broken end of the other shank which is still attached to the butt (assuming that for some reason if you would break the butt if you extract it).

In the process, he cut, filed and resized both ends.

I cannot see any reason why it would not be advisable to extract the broken shank from the butt. There are plenty of reasons it would not be advisable to try to repair a broken shank.

My method of removing broken shanks from butts is to cut off the shank flush, drill a small hole down the middle of the remainder, put a few drops of water down the hole, and wait for it to soak out and loosen the glue. Then use a larger drill bit to remove the remainder. It takes less time than trying to do a patch.

[quote=C
What if the inside diameter of the straw is much greater than the diameter of the shank ? What purpose does the straw sleeve serve it's not glued to the shank ? [/quote]

Never mind. As someone pointed out, drinking straws are not the same size as they once were. I bet they're a bigger diameter now due to the obesity epidemic these days.

It makes no sense to try to connect part of a new shank to part of an old shank.

If its a clean elongated break, you can glue it back together and use thread or a good fitting sleeve.

Otherwise, just replace it.

Does anyone try to orient the grain,like a baseball bat, to reduce the risk of the shank breaking?

Yup. The speckled line of narrower grain should face the strings. I forget what it's called...

--Cy--

Is the sleeve supposed to be fitting ? Or are we supposed to glue the sleeve to the shank ?

As the shank is part of the resonant system of the piano, it is an important part ( a dull note is sometime traced to a soft shank).

On a little value vertical, or one with small cedar shanks (they are difficult to find) I would glue back and use a small thread around the gluing so it is reinforced. The method provided with a drink pipe is also very good.

I had good luck using a drop of cyano glue on one side and Titebond (white) on the other, the cyano keep the parts together immediately (it react to moisture it even worked on a neat break )

On a piano with some value, I would select a shank (sounding it on a metal part so to avoid soft shank and use the thin grained ones in the treble)

Then I moist a finger to find the grain orientation (small white marls on the direction of grain) and I put a pencil mark on the end of the shank to remind that.

If I have to use a thicker shank I will work it with a knife so to have the same elasticity than its neighbors.

On a grand I change the shank,eventually I would take the first one to use in the medium and have the new part on note 1.

To take out the broken shank from the butt all good methods have been provided. I now use the hair iron ( to straighten the hair, not mine of course, I will keep my dread locks !) to heat the butt , it soften the glue very quick it it is a vinyl glue, moistening with alcohol/water is necessary - cutting the collar, if it is hide glue)

The shank can often be taken out without a special plier with that method (heat is high, I take care not to over heat the leather) I have little dentist chisel to clean the inside of the hole.

Tuner2 , it is nice to see someone which that much experiment and willing to share, there (not to say that it misses to some but the more is the better !)

Kamin...Merci, mon ami.

The sleeve should be a snug fit, and the glue keeps it from moving. A loose fitting sleeve would be of little to no value in reinforcing the joint.