Glassing the block

[Ron Overs]

---------------------- multipart/alternative attachment
Terry, Del and all,

>----- Original Message -----
>From: <mailto:mfarrel2@tampabay.rr.com>Terry Farrell
>
>Hello Del. When you wax your plate flange, you must use some thin, 
>wipe-on type of wax, such that it doesn't fill small depressions 
>that may be present in the plate flange surface - or is that not 
>really a big deal? What do you do.

We grind the plate flanges to remove the small depressions before 
applying the release agent, otherwise there is a risk of the epoxy 
keying the pinblock to the plate. While this will be less of a 
problem with single flanged plates, our pianos have a flange either 
side of the pin block (front and rear). Since we epoxy fit the plank 
to both flange faces (before the plank is fitted to the case - while 
screwed to the plate), we would run a big risk of gluing it in for 
keeps, unless the plate flanges are free of depressions.

>  How thick do you make your epoxy mixture - peanut butter?

We use an Australian made paste-like industrial epoxy which has 
similar strength properties to West System (which we use for other 
uses such as gluing up our multi-laminated bridge caps).

>  Also, when you put your epoxy mixture in, what is your exact 
>procedure in order to avoid having excess epoxy migrate to the area 
>between the pinblock top and the plate web bottom and thus impair 
>the fit. Do you screw the pinblock to the plate first and then 
>mooosh epoxy into any small gaps between the pinblock and flange? Or 
>do you put a bead of epoxy on the flange edge of the pinblock and 
>draw it into the flange somehow? Thanks.
>
>The wax is standard floor wax.

Ditto.

>  Others use a spray-on mold release. Either works.
>
>The consistency is about like peanut butter.
>
>The pinblock is shaped for a good wood-to-flange fit first. Then the 
>epoxy matrix is troweled on to the pinblock (front) surface with a 
>suitable putty knife and the pinblock is screwed in place. There may 
>be some migration up over the top because there is inevitably some 
>space between the top of the pinblock and the bottom of the plate 
>tuning pin panel. Unless, of course, you've done a perfect fit along 
>the top as well. I've never managed to do that quite. The excess 
>will clean off. When the epoxy has cured, disassemble the pinblock 
>and clean it up. Knock off the squeeze-out along the edges, etc. I 
>go over the whole thing with 60-grit sandpaper lightly to smooth of 
>the roughness from the casting but not enough to alter the fit.
>
>There are other procedures that probably work just as well. This is 
>mine. I use the epoxy matrix to improve an already good 
>pinblock-to-plate fit. Others simply hack out the block on a bandsaw 
>and use the epoxy matrix to mate the whole thing. That seems to work 
>as well but I've never been comfortable with the idea of it.
>
>Del

This has been my experience too Del. Epoxy should not be used as a 
fix for a poorly fitted block, it should be used to make a well 
fitted block near perfect. If used in this way, you will never have a 
problem with the paste type epoxy running around to the top face of 
the pin block.

I'm sold on this idea of epoxy fitting blocks. It really helps tuning 
stability.

Regards,

Ron O
-- 
                  OVERS PIANOS
        Grand Piano Manufacturers
_____________________________

Web:    http://www.overspianos.com.au
Email:  mailto:ron@overspianos.com.au
_____________________________
---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/32/d7/13/2f/attachment.htm

---------------------- multipart/alternative attachment--