In a message dated 96-07-21 16:50:29 EDT, you write: >Helo all, > >In the UK we would automatically repin any stiff or losse flange, >without giving it a second thought. There are very few in the UK who >have heard of centre pin lubricants and even fewer who use them. > >The reamers that we use in the UK are in the main one size down centre >pin roughed up with a file and placed in a pin vice. a perfect size >reamer for the job. about 15 years ago I did purchase a full set of 24 >straight reamers and I did find them very good, but slow, since then I >use the roughed up centre pin and quarter sized centre pins. You will >find the majority of piano tuners in the UK use this method but only >stock half size centre pins instead of the quarter size. > >The centre pin lubricant you refer to, do you have to remove each >hammer to apply it or is there some applicating device which allows you >to keep the parts in place. > > The only experience I've had with centre pin lubricant was in the early >80's and we found that on all the pianos it sometimes caused more >problems than it solved, as it being or was an alcohol based product >this tended to eat away at the animal glue, thus if it didn't wok and >you had to recentre. Pushing out the stiff centre pins sometimes >resulted in the bushing coming out with it. > >Kind regards, > >Barrie. > > > > Hello Barrie and list, I use to use a center pin one-half size smaller and roughed with a file (between 2 files actually) and that worked fine but I find the straight reamers that Don Maninno developed worked much better and faster. The reason they are better is that these reamers burnish the felt as well as remove felt if that is what is needed. I believe the reasoning behind the burnishing is that it makes for a more stable fit and reduces the chance of the flange sticking at a later time. As far as the lubricants are concerned I think they have their place if properly used. Suppose you have an old Steinway action that is still plenty functional but all the centers are slightly tight. For instance you raise all the hammers to about 60 or 70 degrees and they just slowly return. I wouldn't hesitate to use the pro-tech lube that Pianotek sells. Most likely what would be causing the sluggish action in the above mentioned scenario would be verdigris and that particular solution seems to work well. If the cause is verdigris and it is bad enough to cause serious sluggishness then the only way to properly correct the problem is to change the parts IMO. Interestingly, I have found that the pro-tech lube does NOT work well in all instances. I tried some on a sluggish yamaha one time and it actually made the flanges stick more. Also on a newer Steinway one time I tried it just on one flange as an expieriment and it made it tighter. In some instances I have had good success with a mixture of silicone and VM&P naptha. Example; a Wurlitzer drop action that was so sluggish when you would depress the soft pedal the hammers would not return when you released the pedal or maybe some very slowly returned. Would you repin that whole action? I would not. I am very careful on which brand pianos I would put silicone on however. Also there is the mixture of Methyl alchol and water which actually shrinks the bushing. This works well especially with Baldwins and I have used it with some of the Korean pianos. You could mix it at 8 parts alchol to 1 part water but that is almost too strong I think 16:1 might be safer. On all these solutions I just use the small plastic bottles with a long flexible spout that Pianotek or any of the supply houses carry. Sorry for the long windedness. Doug Hershberger, RPT
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