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I'm replacing a set a hammers on a 1981 knabe spinet. It's my first time doing a whole set, so I wanted to buy them already bored. I didn't think to take measurements of the current hammers when I was at the client's house, and they live an hour away. Is it possible to buy the right hammers without having to go back to measure? Perhaps the hammers were rather standardized for this maker and year?
Thanks!

Possibly for the model and year, but not likely for the maker and year. However, Aeolian used two different shank diameters for small verticals, and I would not know which was used for this particular piano.

A set of hammers is likely to cost more than the piano is worth, even before installation. This is a job I would not recommend anyone having done.

Are you sure it is a spinet. I don't think Aeolian made any spinets with the Knabe brand. I suspect it is a console piano.

Is the action a direct blow or does it have a drop action?

Once you know this you someone can probably get you the shank diameter and bore distances. From this, Ronsen could make you a set of hammers. Make sure any hammers you get are not too heavy. Heavy hammers kill the tone by staying on the string too long. Especially in the treble.

The piano's serial number is 195251 if that helps. I thought it was a spinet when I saw it. I could be wrong, but I believe that's what it was. It appeared to have a drop action. The piano is nothing too amazing, but it has some sentimental value, so the owners want to get new hammers. There were 30 or so that the felt was coming off of. Thank you all for your help!

You are going to have to measure, or even better, get samples. Depending on the cost of the hammers I would use, I suspect that I would have to charge $1500-2000 for a job like this, and plan for 2 or 3 hours more if it really is a spinet, and maybe more if it has a lyre.

The shorter the piano, the harder the hammer change.

The easy way is to have the heads re felted.

To obtain new hammers heads, the easy way is to send samples and measure the angles.

It is not very useful to change the heads if you do not know how to pre voice and shape them before installation. First voicing on glued upright hammers is not really easy.

Pre needling allow to needle enough the underside of the heads.

If you want to respect the original strike line, new shanks need to be planned. It is because the new parts rarely have the same exact angles and deepness of bore, then the new hammer strike a little higher or lower, and is then on the right or the left of the choir.
Even with new shanks iH is necessary to cut in wedge the bottom of some shanks just to center the crown on the choir (by tilting a bit the shank)

Mounting new hammers on the old shanks is possible, but easier on a tall enough piano. And the lining of the heads is never perfect in that case.

Also if hide glue was used, use hide glue, if vinyl glue was used, use vinyl glue.
On original shanks the glue will drip. It can be necessary to make samples and tilt the whole action for gluing.

Re felting is clearly the simplest solution.

I would not buy prebored hammers for a spinet. The rake is too precise. You can use a heat gun and remove the hammers and send them to a company that will copy them.

You could also just reglue the felt.

Good luck

How would I go about gluing the felt? There are so many that are coming off, that I'd probably have to do the whole set, and there are 2 that I couldn't find. I thought they may have just fallen into the piano, but no luck. I never heard of getting hammers refelted. What's that all about?

I dont know if some hammer company does this in USA.

Here you pack and send the parts to Renner, Abel, or Desfougeres in France, wait one month , and receive the heads with new felt glued on them.

to mount new hammers you need to have the piano at hand, mounting them on the action will be difficult, we need at last samples glued in the instrument.

PianoTuna - For a spinet, console or upright, I would offer the alternative of gluing and wrapping the old felts back onto the moldings. When I do this, I always do the entire set, including those which are currently okay, just to prevent problems down the road. I've done this on dozens of pianos, and have never had a problem crop up again. Here's what they end up looking like when I do a set:

[img:center][/img]

weird ! never find that re glued felts can provide any amount of tone, the tension is totally lost. Not that it is so bad looking but is the result worth the trouble ?

Olek - So, you believe that the tension that goes into stretching the felt fibers is lost once the glue bond between the felt and the wooden molding lets loose? In other words, it's like a string when it breaks, releasing all the tension on the string?

I really don't think it works that way. The glue bond does not hold all that tension in check. The individual fibers that are pull around the point of the molding don't suddenly snap back into their pre-stretching configuration.

With a spinet especially, the question of whether the hammer is 100% or 90% of its original tonal quality seems to be a moot point. If the hammer felts are falling off the moldings, gluing them back into place and using a thread wrapping to prevent future problems is a low-cost and effective means to solve the issue.

Or, if the customer has deep pockets and the piano has emotional attachments, I'm always glad to order a new set of hammers from Schaff and install them. The gluing / wrapping option just provides them with a much lower cost alternative.

Chuck Behm

Thanks. This particular client is willing to spend the money for new hammers, but the threading and gluing would probably be a good option for some of my customers. Thank you so much for the picture. Would you use hide glue for that? And is there such a thing as getting replacement felts and just having some to carry around in case there's a customer who just lost one or two? Maybe I could voice it and glue it on if I had different sizes?

Dear P.T. - Just wondering - have you installed new hammers before? If not, you might consider acquiring a freebie spinet or console to practice on before you attempt it on a customer's piano. If you're good to go, then by all means if the customer is willing to spring for a set, and if they are apprised of the fact that by installing a set of new hammers on a spinet, the commercial value of the instrument will not go up by a corresponding amount, then go for it.

The nice thing about the gluing and wrapping option is that it renders the piano useable for a much lower cost to the customer. I charge $500 less for wrapping and gluing than I do for a new set of hammers.

If you would like, I would be glad to post a set of photos showing the step-by-step procedures I use for gluing and wrapping. It's a bit tricky to get the hang of, but once you do the result is a very professional looking repair that the customer is happy to pay for.

Also, I have a tutorial that I wrote for installing hammers on a vertical action if you would like me to post that.

Good luck either way with your project! Chuck Behm

if interested by the traditional way on "normal" uprights you can look at that video.

you may see what I mean with the pre voicing and prep before hanging

this is considered standard professional level here. But it happens only the heads are changed (on smaller pianos often)

any way, without voicing the job is not complete, repairing pianos is not just a question of installing new parts and felts / strings


good luck

with re-glued hammer felts I never could obtain a similar tone and dynamics than the hammers that where not unglued in the set.

replacing the heads is not the long part in the job, and a vertical hammer set is not expensive


[video:youtube]KmosHq9w_cE[/video]

that one may also interest you; upright hammers are sounding better when the tone is much rounded, starting with dense heads can help assuming they do not loose consistency when needled;

The job moves the felt tension (the more long fiber felt is used the more efficient the needling) allowing it to be more resilient at some location.

[video:youtube]UtkUZIh9uBg[/video]

Thank you Chuck. Any videos or pictures you have would be much appreciated. The wrapping in your pictures does look very professional and I'd definitely like to learn it. Some of my customers don't have a lot of money and would probably like that option.

Everyone, I have replaced single hammers before, but never a whole set. I know that voicing a whole set is tricky. Would this be done after all the hammers are already installed, or before?

You really do strange things (changing A hammer but not a set ) !!


I do not get why the hammers of the picture did unglue, that sort of thing do not happen with good quality hammers, even a 220 USD cheap set from Abel do not get unglued that way.

I think regluing the heads is too much time consuming in regard of the expected result, this is not really a good service to the customer in my opinion. (the customer pay for that)

Now if only a few ones in basses for instance, need to be re-glued why not, but doing the whole set ?
I even tried to re glue with a strong pressing (with vice grips, or with the special springs that are sold for that) No way to blend the re-glued hammers in the set; they always sound muffled and have zero dynamics. lacquering necessary then but still it was deceiving.

Isaac, you did not read the waterproof piano thread. Tsk tsk tsk.

I had video taped myself doing this repair to a few loose hammers and I have posted it here:

http://youtu.be/s4ISCP-n6_c

I hope it helps you out pianotuna. Everyone else, feel free to make fun of my hack job on the threads.

(Note: it might not be online yet. 4:43 ETD)

Olek - I can't speak for other regions of the U.S., but here in Iowa, where it gets swelteringly hot and humid in the summer, and cold and dry as a bone in the winter, this problem is all too common, especially in lower tier pianos - exactly the type that wouldn't be suitable for an expensive hammer replacement job.

Hope that helps you understand. Chuck

I've done such repairs in 3 pianos. It's not common here in Mexico City but it happens from time to time. The owners have refused to replace hammers (too expensive). These were cheap pianos.

Olek is right, these tied/glued hammers lose their tone and dynamics.

This repair only prevents the felt to fall down and ensure the note will sound whenever the key is depressed. That's all.

Thanks, I understand, but they could keep their piano in a decent place, or is it really so complicated ?

Anyway when the felts unglue the piano hammers are dead.
Buying cheap piana is a bad decision generally speaking, particularly when the Chines factories provide decent instruments today, with good parts.

Changing the heads only on a small upright is not that long when used to do it (and when we know where the traps are) .

the job can be done in 2 days, the parts are not expensive, the tonal result is excellent, I would better train to do that job than to train in felt re-gluing (as you proposed to pianotuna)

The video of our colleague from AUstria, he spend a lot of time on hammer needling, one by one, for whatever reason he choose. This can be done way faster by working about 12 20 hammers at once in a gig, hopefully.

Dismounting and putting back the hammers and butts is fast with the European uprights, some colleague dismount the hammers just for reshaping. (the advantage of those small metal plate that hold the butt on the center pin)

Isaac,

What you say may be true but how do you rationalize a 2 day job as being inexpensive and a better fit for the customer.

A two day job for me would cost $1,000. What used spinet is even worth that. But pianotuna does say it is a sentimental piano. Did he offer to replace the hammers?

The same thing happens with cars, if you cannot buy another one you have it repaired.

Isaac - What does humidity and sweltering heat have to do with keeping a piano in a decent place? And why, I have to ask, do you (and so many others) feel compelled to argue every issue?

Here's the situation (which is typical) for the last piano I completed this repair on. A single mother with 2 children taking lessons living on the 3rd floor of an older apartment building without an elevator. She has a 1960's something Baldwin spinet, which was "free" for the hauling but which she had to pay $500 to have delivered to her apartment. The first couple times I tuned it, I tied several hammers on each trip that had come loose and charged her a minimal fee. This last time five hammers had loosened up, a couple on the bottom of the molding, a couple on the top, and one on both bottom and top which had fallen off.

I gave her quotes for both replacing the entire set of hammers, and for wrapping and gluing the entire set for a fraction of that cost. For both options I offered a no interest payment plan for 12 months in which she would write out a series of post-dated checks, to make it possible for her to swing it. The difference in options meant the difference in writing out checks with 3 digits, and writing out checks with 2 digits.

Granted, a hammer which has been reglued and tied might have a somewhat lower tonal quality than its neighbors, but I'm willing to bet that on a 1960's Baldwin spinet, it would take a highly trained ear to detect the difference. Certainly, the two children taking lessons aren't going to be aware of any difference. They do notice, however, when a hammer felt falls down into the action and jams up several notes in a row. The added benefit to wrapping the entire set (besides preventing future problems) is that the hammers that have thus far held together will continue to do so, in order for their pristine 1960's Baldwin spinet tone will remain in its crystal clear condition.

The thing is, for a person on a budget (which this gal definitely was), this is often the best option. "Why not just have her get another piano?" you ask. On her limited income, what's she going to be able to afford? Most likely another free for the hauling or very cheap older spinet or console which will come with its own issues to be repaired. She would have to pay at least $500 to have it delivered and probably more, since the mover will charge to haul the old one away.

In a perfect world (which some of you seem to assume exists) I would just have her go out and buy a new U-3 and call it a day. After suggesting that, I would go home to my villa and sip a glass of cognac while lounging by my pool.

Right.

Now, argue away, Isaac. I'm sure you'll come up with reasons why this makes no sense to you. Chuck

P.S. Mark - I'll post photos tonight that I promised of my method for tying. I've got to run to do 3 tunings.

Chuck, Thanks for the detailed explanations. Did she ask you before taking the piano? Or a movers address?

If I had to deal with those situations I would look for a fast method to secure the felts.
For instance a pneumatic staple machine, with the thin staples used for wood assembly. They have a U shape a few mm large, and are easy to bend once they pass thru.

If I where in piano tuna position I would propose a not expensive deal on new heads so to gain experience.
Best regards

OK. The video's online.

http://howtotunepianos.com/regluing-hammer-felt/

Comments appreciated.

About my staple idea, the cheap hammer staples are not passing in the wood, so may be it is necessary to drill a hole to install the "real staple. (t rivet)

Bur many be it could be tested, possibly twisting the back as on old Steinway .

I think of those staples

Using strong pliers to compress the felt then passing the staple and secure it may allow to have some resiliency back. I will test the feasibility with my compressed air staple/nailer.

There are also "nails" that are used with the pneumatic stapler,they are t shaped but too small probably.

also it may be possible to use 2 or 3 staples if they are thin enough

That would be faster than the system with the thread.

Those pneumatic stapler are excellent tools

Hi Mark - I watched your video - nicely done. The main difference in our methods is that I remove the hammer assembly from the action before wrapping the hammers. It takes a bit longer, I'm sure, but I remove an entire section at once, then put them all back at the same time once they're all wrapped, so I don't think it would be a whole lot different in terms of time. Your method most likely is as effective as far as holding the hammers together. Mine does look nicer, but it's purely a cosmetic consideration.

Anyway, I posted a set of photos on my business facebook page - it should appear right at the top of the page. I'll post them here if necessary, but it's a pain compared to loading them into the facebook page. Here's the URL of my page - let me know if you can't access it:

Behm Piano Service

Hi P.T. - I mentioned earlier that I had written a procedural article about installing hammers for Schaff - I don't think Rob Johnson ever got around to having it loaded into their website - we just shot it out one time in an email to his Constant Contant list. Obviously, it features Schaff hammers and products, but the methods would work with whatever hammers you purchased. The ones I buy are pre-bored, so buying a set that was not bored would entail more steps.

As with anything else, methods vary, so read a variety of approaches, and decide what works best for you. Here's the link: Upright Hammer Replacement

Thank you all so much. You are all so enormously helpful. This is a problem I see all the time because of the terrible fluctuations in weather in Buffalo. So i know ill use the wrapping technique at some point soon. Idid send in the hammers to get them custom bored for this job, because they had the money and were willing to pay it. And thank you for all the videos and pictures!

About th document for Schaff ;

the strike find on the old worn hammers is not original, that, and the hole in the hammer for glue escapement ,are the 2 points I would not follow

They also say nothing of voicing

no need to take out the dampers, if the shanks are replaced.


the shanks need to be spaced perfectly before mounting the new heads (no as on the first page picture)

in fact the new dampers are installed first; usually, then the new heads on new shanks (sorted and oriented)

a channel done on one side of the shank allow glue to escape, the dot of glue on the top of the head would be considered bad looking.

good luck with that first hammer job