When I first started doing this work and was trying to make
a mirror finish on the pieces, I had a problem with firescale in
the final stages of polishing. Now I am texturing most of my pieces
instead of polishing highly. My question is, will firescale show up
at some time later if it is not visible after texturing?
A fire stain (fire scale is the black oxide left after heating,
which pickles off. Fire stain is the grayish shadow you find when
you polish) surface will probably look fine with the texture. But if
it oxidizes over time, the fire stained portions will tend to oxidize
differently than the clean sterling, so then the surface may look a
little blotchier than it otherwise would have.
Nevertheless, I’m forced top wonder why, every so often, a new crop
of folks here on Orchid come and start discussing fire scale and fire
stain, and their apparent inability to prevent it.
You don’t have to put up with the stuff. Learn to use prips flux,
guys. It’s a fuss and bother, sure. But it’s really cheap to make,
safe to use, and does indeed, when used correctly, prevent the
formation of fire scale and fire stain.
I’ve posted, several times over the years, a somewhat wordy article
here on Orchid about the use and preparation of prips flux. Go find
There are, if I recall (I’m not looking at it right now, so this is
memory only, which may be wrong) a couple minor errors in that
article when you find it.
First is the spelling. It’s Prips flux, not Pripp (with two "t"s).
Jack Prip doesn’t spell his last name with two t’s, and the flux
named after him shouldn’t either. So don’t perpetuate my initial
Second, and I don’t remember if I corrected this or not in the
postings you’ll find in the archives. At one point I wrote the
simple recipe of a quart of water with 80 grams each of borax and
TSP, with 120 grams of Boric acid. That amount of chemical won’t
quite dissolve in a quart of water, so then you’ve got to bother with
adding additional water. It WILL dissolve, barely, in a LITER of
water. For a quart, use 64:64:96. The important thing is the
2:2:3 ratio anyway, but the above quantities will be easier to mix up
if you’re not trying to dissolve more than will go into the container
you’ve got… Note that some school studios mix these amounts with
a gallon of water. makes for a more dilute mix, which is cheaper and
fine for students who are really happy and extravagant with spray
bottles. But the more concentrated solution actually is easier to
apply, especially with an atomizer type sprayer rather than a
trigger bottle. Atomizer types work a lot better, with a more even
spray of smaller droplets.
Please feel free to contact me either off list or on, if you’ve got
trouble using prips flux. it DOES work. Then you don’t have to
worry about how to remove it, if you’ve never allowed it to form in
the first place. The time spent using the flux is much more than
saved in the clean up and polishing stages.