• 1.  rendering solutions

    Posted 05-13-2022 16:14
    I'm going to be tuning a Baldwin SD-6. I tuned this piano years ago and the rendering was awful. I was informed through the pianotech news group the brass formula was the problem. Something about a stickyness between the steel and brass. I tried protex back then to no avail..
    Of course I will try Jon's CBL but Fantastic?. Clean carefully with a few drops of fantastic then apply the CBL. I wonder if there will be a reaction between the two?
    I said to the guy who called,, "That's a difficult piano to tune" and he said yeah it is.
    Any other ideas? McLube dry bonding lube?
    Thank you

    Keith Roberts
    Hathaway Pines CA

  • 2.  RE: rendering solutions

    Posted 05-13-2022 17:36
    CBL, no prep.


    Jon Page

  • 3.  RE: rendering solutions

    Registered Piano Technician
    Posted 05-13-2022 17:47
    That's what I would use...CBL

    Peter Grey Piano Doctor

    Peter Grey
    Stratham NH

  • 4.  RE: rendering solutions

    Registered Piano Technician
    Posted 05-13-2022 20:06

    I improved the stubborn rendering through the fittings in the capo sections of an early Baldwin SD-10 by slacking the wires a note at a time, pulling them aside, laying 6B graphite (from a pencil) into the long counter bearing grooves, and then taking strips of medium emery cloth and shoe-shining the gently curved main bearings. Slacking the wires and then pulling them back to pitch automatically assured that some wire would have gone around the hitch pin (because, of course, one side is always let down before the other), so all the bearing points had fresh wire.

    Tuning ease and stability were greatly increased, the tuning lasted through concerts much better, and people started to like the instrument when they had barely tolerated it before.

  • 5.  RE: rendering solutions

    Posted 05-14-2022 13:16
    Very interesting Susan,
    I believe the capo bars on the SD-10 did have a problem. My Aunt had one of those with the Renner action. These are the agraffes on a late 40's SD-6 the concert grand. Someone posted 18 years ago that it was the brass that was at fault and the only way was to replace them. However you gave me an idea to try a few things if the CBL has little or no effect.
    Graphite is a good one.
    Molybdenum bonds to the metals. Clean the wire and agraffe with fantastic. A very small dab of the grease,,, Work the wire. Isopropyl cleanup then electronic spray finish. Use desired lube,, probably CBL

    Keith Roberts
    Hathaway Pines CA

  • 6.  RE: rendering solutions

    Registered Piano Technician
    Posted 05-14-2022 15:16

    HI, Keith

    I'm a little worried by the molybdenum. I feel that ZERO friction is not desirable, and I'm wondering if it could be removed should it be TOO slippery.

    After all, tuning stability gets worse if the wire can always slide very freely across the bearing. You want to be able to render the wire when tuning, so it should not be totally stuck or moving erratically by jerks, but you don't want it to render when the pianist plays one double forte chord, even if the tuning "self-heals" from a single forte chord afterwards.

    I've sometimes had to tune one very old D, used to be concert and artist, where just putting the tuning hammer on the tuning pin was enough to change the pitch. Not at all a benign situation.

  • 7.  RE: rendering solutions

    Posted 05-14-2022 17:52
    I think I remember the front duplexes being at a sharp angle. I would think the friction at the agraffe should be low and it's the friction across the front scale that gives the tuning stability. I doubt the molybdenum is permanent as the penetration into the metal can't be deep. 
    A wire that doesn't move at the agraffe and moves even less at the bridge will break on FFF blows is another potential. Eventually a wire will gain friction at the agraffe which is why Jon's CBL is getting great reviews. 
    Another tuner might have stressed a wire that doesn't move at the agraffe. It doesn't take much of a pull to bring the short front scale to breaking strength. After dropping pitch it needs to come back up smoothly. Yes I use a jeck technique many a times. 
    I doubt a piano player can achieve FFF as the people who put the new hammers on,, short bored,, and hacked the old piano disc system in, screwed it up. When they finally ok'd me doing some regulation, I found the stack had been pinned about an 1/8 inch off the key frame on the back side by whomever put the screws in. Those angled screws do that. They didn't like the $800 bill I handed them. I actually got the pianodisc system working decently. I doubt it still does. they said it doesn't get played any more. It is connected to the pipe organ at the vineyards main hall. 

  • 8.  RE: rendering solutions

    Registered Piano Technician
    Posted 05-14-2022 19:25

    Ah, a piano with ..... history, I guess you'd call it.

    Good luck with it. Let us know how things went when you next see it?