An "easy" blueing process?

[David Parkhurst]

I'm faced with the need to re-blue a couple of dozen round-head screws
from the pressure bar of a 1876 Steinway upright. Locally I've not been
able to find anyone who does this work (except a shadowy individual who
works through a gun shop every few months or so!) and so wonder if I can
just do it myself. Does anyone have experience in this?

The only *reasonable* recipe I've found so far involves melting a quantity
of potassium nitrate (saltpeter), which happens at about 600 degrees F.,
and dipping the polished and cleaned screws into it for a few moments
until the desired shade of blueing is achieved then washing them in cold
water.

I can imagine there could be severe hazards associated with this process
(like explosions) and so have not yet attempted it.  The screws in
question are unique in that they possess extra high rounded tops of a
sort I've never seen available today, so I'd like to reuse them. The deep
blue of the screw heads contrasts nicely with the brass of the pressure bar.


***************
David Parkhurst
Associate member
San Francisco Chapter -- PTG
wind@crl.com