Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Sostenuto tabs dried up

Dried up sheet rubber used as sostenuto tabs

I have two Kranich and Bach pianos each about 80 years old .

Instead of using a sostenuto rod it has a wooden rail with sheet rubber
tabs to catch the damper lifter.

<IMG SRC="http://users.rcn.com/woodfab/tabs.jpg"

The old rubber is completely dried out.

I'm thinking of using sheet rubber gasket material from the local auto
parts store but I'm thinking it may harden over time.

Question is , Where would be a good source to the material for this

Thanks, Dan

I have used the rubber gasket material. If it is good for 50 years, then it becomes someone else's problem.

I seem to remember that glycerin keeps rubber from drying out. Maybe apply some when new and every five years down the road??

Even regular 3-in-1 oil can help. A friend showed me that trick for rejuvenating spinet rubber grommets before disconnecting the stickers to pull the action. Put a drop or two on each one, and let it absorb for a while. Makes it a snap to reinsert them into the forks, too!

--Cy--

(OK, so what's the equivalent word for "rehydrate" that applies to oil? "Replasticize"?!?)

Red gasket rubber worked for me in similar circumstances. The edge was beveled to fit the spikes on the top flanges. Oxydized rubber is beyond saving. Beware of using petroleum products on rubber.
Tom

Thanks for your replies.
I was sitting here and I thought that the problem with the sheet rubber from the local hardware/auto store has no manufacture name on it.
I learned over the years the cheep rubber doesn't last, I've had Taiwan and some other import pneumatic hoses dried up in a couple of years but a Goodyear one I have is still good after 18 years.
I then thought Goodyear makes sheet rubber in .050" for roofing and it's guaranteed for 40 years. I got a piece and it's perfect.
Thanks again, Dan

McKittricks Industrial Hardware Store
Lowell MA
978 458 4593

Ask for Bob Mckittrick
Mention me

They have a tremendous selection of rubber gasket material

Larry Buck

I have a Kranich and Bach grand in the shop,

Doing the back action now.

They departed from the rubber and there is a type of plastic looking material. I know plastic was not invented yet.

Regardless, it is still in great shape after 90 years.

Do not use oil on rubber! Grommets may be neoprene. The original on the Kranich & Bachs may be leather.

I learned the hard way about petroleum products on rubber.
One day my car was low on brake fluid and I had a can of hydraulic fluid, I thought the brake system is hydraulic so it should work.
Well within two days every o-ring seal in the brake system failed. Come to find out the hydraulic fluid was petroleum based.
It was pretty funny to say the least.
I'll check out McKittricks Industrial Hardware Store

Hello Larry,
You mentioned that the tabs on the Kranich and Bach in your shop uses a type of plastic.
Plastic makes me think of a material that's ridged.
The tabs on the 1912 Kranich and Bach I have look in nice shape but have lost their flexibility and will not deflect when damper lifter raises as they should in order to work as designed, they will only up a damper if the pedal is depressed after a note is played.
Dan

Dan,

I would suggest you look at my Kranich's back action when you can.

Thanks for saving me from a disaster!

Is there an appropriate solvent? It works so great (for a while)...

--Cy--

Dan

I'll take a picture of the back action and post it here sometime Tuesday eve of Wed am.

I did get your call today. I was on the road all day from 7:30am until 9pm.