I am seeking help solving a problem. The piano is a 1988 Baldwin L. I did some action work; new hammers, shanks, replaced the key bushings and regulated. It was all pretty straight forward.
Before I did any work I measured all the down weights and up weights. Most of the down weights were between 58 and 61 and up weights were in the normal range. Although I thought it was a little bit heavy the client liked the way the action played and did not want to change that.
With the work that has been done so far the down weights and up weights are almost exactly the same, except on 12 notes. There are 12 notes that have down weights between 68 and 70 grams. They are mostly in the low bass but also 2 in the low tenor.
I cannot find any friction problem or any reason for these 12 notes to be different, and play so much heavier than the others. The key bushings are free, they are not rubbing on their neighbors. Key pins and capstans were polished and then I applied teflon powder. Knuckles and whippens heels also burnished with teflon power.
I'm supposed to return it Monday, but I can't bring it back with 12 notes so radically different from the others.
I've trying to figure this out and so far have not been successful.
I've used VS Profelt for this on the wippen cushions, and yes, it does help lower the DW a bit.
Also check the balance rail hole at the bottom of the key. You should be able to slightly lift the key and it should fall down easily.
Comment from Jon Page: "On those 12 notes, if the UW is also above the others, there is a lack of lead in the front of the key. If the friction is the same, lead deficiency."
That is the conclusion I finally came to. My measurements reveal that there is not a friction problem, but the heavier notes do have UW above the others. Additionally there is very little leading in the keys. This makes me think I should add lead to the 12 heavy keys.
When I started the project I did not take DW and UW measurements of all 88 keys. I only took measurements of all the C notes. That was a mistake, I'll call it a lesson learned. At the completion of the project I measured DW and UW of all the keys and at that point saw the 12 notes that were too heavy. I now believe that was the situation before I did any work. However since I did not measure all of the notes I was not aware of that.
Thanks for all of the input.