[R-390] R-390 Polishing

[Michael Young]

I am thinking that what we have on many of the R390s is alodine process.
Invented in the late 50's and very popular in the 60s (may still be) it
is/was a strictly chemical process.  The finished product was non-toxic.
Another alternative was anodizing (NaOH etch, followed by electoplate
process in a sulfuric acid bath, then wash then actual dye dip then sealing
the pores.  Hey...I did this in my basement shop as a kid.  Worked great.
To complicated though.  The Alodine process (patented) much easier and
faster.

Mike