Hello, I'm a rebuilder from Belgium and new here.I was wondering, does somebody know how to fix the old Blüthner damper underlever hinge system (sorry for my bad english)? Nowadays all the damper underlevers are attached with centerpins in cashmere (strong red felt) but old Blüthner have an attachment with fabric. The fabric sometimes doesn't stand the test of time. How can one repair it?

Here's a picture for those who are not familiar with this old system:

http://www.pianoatelier.be/bluethner/blutner_010.htm

Jens

The general way to repair something like this is to figure out how it was made and copy the process.

the hinge material is probably vellum. each lever has one end of a small rectangle of vellum inserted into the slot at the end of the lever and the other end is attached to the rail, all held by hide glue. from the pictures, the originals look in pretty good shape. if you undertake repairs, keep the glue off the part of the vellum that has to flex. and remember to keep things aligned because there is no traveling of parts after its all together. good luck.

bcnu
david

If the problems are serious, you might consider fitting a modern Renner back action. In the US these are sold in kit form, and this might be available in Europe as well.

Thanks for the answers. Here in Europe most of the second hand Blüthners have this old system of fabric or vellum. I guess in the US old Blüthners are rather scarce. The problem is that it is as good as impossible to replace the vellum because you the vellum is a tight fit (without screws in the underlever)). The gap is as thin as the fabric, I think they are initially made in a whole block where a big piece of vellum was inserted and then they were sawn into pieces. Maybe I should staple them in from the top.
Anyways muchos gracias

You have to cut out the existing vellum with a vellum saw - which is much thinner than the regular wood saws.

http://www.ptg.org/pipermail/pianotech/2005-June/174770.html

http://www.uk-piano.org/heckscher/hec_leth.html#vellum