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Yesterday I unpacked and tuned a new Estonia 190. Six or seven dampers in the high treble were not returning, and all had the same issue - tight guide rail bushings. (The underlever flanges were all working perfectly.)

I don't know about you, but I really dislike the umbrella easing tool sold by supply houses. I've modified mine, and ground it down to be thinner, but I still think it's too big, and more likely to damage the bushing or even push it out.

So instead I used the largest Don Mannino center pin broach inside the bushing (after removing each damper) and it worked great! I wasn't trying to remove material so much as compact and burnish it from the center out.

Anyone else ever try this? Or can you share other techniques/tool ideas for easing guide rail bushings?

An older tech I know puts a dab of laundry starch on the cloth with an eye dropper and inserts a pointed pin slightly larger than the wire. This will compact the cloth a touch and leave it that way when the pins removed. A bit of CLP on it afterwards and its good to go. This is a good long term solution with lower quality/softer density bushings that are simply sized a little too thick. They typically wear in with use faster than a better/denser material and if you remove material from them, you could end up with sloppy/loose guides down the road.

Insert #6 bridge pin and treat with VS Profelt, or a mix of alcohol and water (more alcohol reduces sizing aggressiveness). Fair warning, I have not personally used either of these techniques.

I heat up a #6 bridge pin and iron the bushing. It's a little tricky to heat it up to the right temperature. I use my temperature controlled shank twisting pliers set on low. It works immediately and seems to hold up well.

Tim

Greetings,
Tight bushings on old pianos are slightly different than the ones on new. Newer bushings that are tightening up (in my experience), seem to have softer, thicker,spongier cloth. This material doesn't stay eased when the traditional tapered punch is used, unless taken to a very loose fit. Older cloth seems less resilient, and will often remain as eased.
Heat has its place if repairs are to be made in the field,as does a fine rat-tail file. When it is a job that has the dampers out,and there is overnight time for it to dry, the use of Pro-felt with appropriately over-sized caul/pins has always given me consistent,durable results.
Regards,

I've been looking for information on the contents and action of VS Profelt, but haven't managed to find anything. Can someone give me a quick run-down?

Greetings,
As I understand it, it is a proprietary mix of water, fabric softener and silicone. When taken up by the felt, with a centerpin in the bushing, there is a significant increase in tightness. When it dries, it shrinks this compressed felt to nearly the exact dimension of the pin, but with a much firmer result. The same thing happens in the key bushings when used with cauls. I only use it in center pinning when I have to install a new bushing. Pro-felting a new centerpin bushing with a #19 pin in it overnight usually gives me a firm, easy to ream, bushing that will stay near where I leave it for a service period or two.
The silicone is just a trace, but seems to keep the heavy use pianos more friction free for a longer time than the key bushings without it.
Regards,

Refer to Journal articles by Bruce Dornfeld, June and July 2010.

Protek. Never had a recurrence.

Protek 'Prolube' works great on damper rail bushings.

I use an upright damper wire with teflon powder to burnish the felt.

Thanks everyone, I appreciate hearing your different ideas, will try them out.

I've used Protek and Prolube with some success before, but it doesn't always work. Dave S, I agree, I've had better results with Spurlock teflon powder, especially after doing some type of easing.

Regarding sizing solutions, probably better suited to the shop - but a concern would be if the sizing solution makes the bushing cloth harder after it dries. Couldn't that lead to rattling damper wires? Especially if it shrunk a little more than expected?

The Steinway method of having an oversized bushing with the damper wire leaning onto one side has the advantage that it will (almost) never result in a tight bushing. So if you happen to over-size the bushing, take that route.

Having the damper wire with pressure on one side of the bushing also acts to damper vibration of the head in a hard blow, or when coming back down onto the string.

On the other hand a red flag for me is that it just came out of the box. When it's a new piano that's been on its side, I always tighten the damper guide rail screws to make sure that the real problem isn't that the guide rail has shifted towards the bass making the wires bind in the guide rail bushing.

Good points Sally. I have seen new pianos with all dampers seated slightly to the left of center...

Agreed. If the bushings (or center pins) are tight, lubrication can work if the problem is only marginal. Normally, re-pinning or re-sizing of the bushing is needed for a reliable long term repair.

Hi Sally, this is a good point that I did not address in the initial post. I did check and the guide rail wasn't loose; also the affected dampers weren't contiguous to each other...

reverse : more alcohol more aggressive (moisture o deeper in the wood, also reaction of the cloth is stronger)

a heated rod woks well (in a flame or with a soldering iron and a goodie to reduce the heating) bushing quality indeed may be taken in account.

Plus one, make use of a lighter and make the (edit: the very end of the...) damper wire incandescent, insert the wire into the guide, repeat if necessary, do not over do.

Regards, a.c.

For dampers that are seizing up: I pop the damper wire out of the guide rail, heat a pointed capstan tool with a lighter just a bit, and carefully iron the bushing.

I've used Protek to good effect but I'm alway concerned about applying a liquid lubricant to felt. I apply it lightly to the damper wire after cleaning it. I prefer using microfine teflon powder directly on the felt bushings.