[pianotech] finishing a plate

[Ron Nossaman]

Nick Gravagne wrote:
> I've had the best luck with countersinks, and installing 
> vertical hitches, by beveling the hole edge before the final 
> bronze coat. With the countersinks, I use a countersink (or 
> rotary file) of a shallower angle to knock the top edge off.
> 
> N writes:
> 
> These are metal cutting countersinks?

Indeed. It doesn't take much. You're both removing the built 
up finish, and installing another "corner" between the screw 
head and plate surface, so the mashed finish buildup doesn't 
lever the surface coat off. It cracks off at that new edge, 
where the finish is thinnest.


> R again:
> 
> For plate perimeter bolts, a small thin washer that does the 
> damage far enough under the lag or nut head that it doesn't show.
> 
> N asks:
> 
> Where do you get these washers? They must be unusual, requiring a large
> hole, a smaller OA diameter than the lag head, yet relatively thin.

Now that's a problem. I found some aluminum washers, about 
0.035" thick, 0.385" ID, and 0.620" OD at my trusty salvage 
yard. I nearly always get to install adjustable plate bolts, 
and these work very well with the 3/8-16x4" set screws and cap 
nut. I fill plat perimeter holes with epoxy and iron filings 
and re-drill to fit. For different lag sizes, it's going to 
take some hunting, since this isn't usual Ace stock.


> What do you folks do about hitch pins? Do you 
> have birthdays while you mask and un-mask each one, or just 
> spray over them and blow off the chips after stringing?
> 
> N: 
> 
> Like the "birthday thing" <G>. I don't care for the look of sprayed over
> hitch pins, plus the new finish tends to crack and rotate on the pins
> when stringing. I learned (can't remember from whom) to make player
> tubing "hats" for all pins (cut them at an angle). First I wire-wheel
> all pins, prep the plate, and then don the hats prior to spraying.

I don't like the sprayed over look either, but I had at least 
one birthday doing the tubing caps, and left spray shadows 
that I also didn't much like.
Ron N