[SEL] More on Parkerizing, bluing, blacking, & browning iron

[Richard Allen]

RickinMontana: More on Parkerizing, bluing, blacking, & browning iron

Hi, Rick,

These processes etch the iron and will destroy finely finished
surfaces. When guns and other fine machines are treated using these
processes, all the finely finished parts are masked or otherwise
protected from the solutions used, especially gun barrel bores. What
John Culp said about the whole process pretty much sums it up. First,
when the blacking solution is mixed up the ammonia released is very
noxious to say the least and if the ingredients were mixed dry it would
be next to deadly. Not quite deadly, but severely damaging to the eyes
and respiratory tract. In fact, ammonia gas is so strong an agent that
it can be felt on contact on your skin, even on the thicker skin of
your hands. In this particular case since it is formed in an aqueous
solution, its release into the air is somewhat moderated by the
formation of semi-stable ammonium hydroxide solution, but there is
surely PLENTY enough released to cause all sorts of trouble
physiologically in contact with your skin, eyes, nose, and whatever
else. It messes up your blood chemistry big time if you manage somehow
to inhale some, although it does go right through your skin and if
exposed for a few minutes it would be enough to start causing other
problems besides skin burns. I hadn’t thought about the neighbors
calling the narcs about the smell, though, I did not know it was
connected that way. Out here in Farmland us farmer types occasionally
inject the ammonia gas right into the ground as fertilizer and in that
respect smelling it out here it would not raise any eyebrows at all.

I thought you wanted to Parkerize or blue/black the lathe knobs and
cranks, not the surfaces of the ways, gear teeth, etc. These processes
are totally out of the question for parts like that, especially if you
wanted to do the bed. You’d need to have a vat deep enough to dip the
lathe bed into while it simmered away at 300° F, and even a pot big
enough to cook a missionary or two in would not be big enough! And then
making the couple hundred gallons of solution would be a problem as
well. Sorry! For protecting your lathe parts a liberal painting with
regular old cheap motor oil with the current API rating that is
accepted for engine warranty protection by Ford, GM, and Chrysler - - -
woops, Daimler-Chrysler now, is all I use on my milling machine, drill
press, old lathe, etc. The anti-corrosion additives work great for
protecting bare steel and cast iron. As you have most likely observed,
freshly machined cast iron is about the most rust-prone iron alloy
there is, but good old modern motor oil with all of its corrosion
inhibitor additives is fine for even that. But the Parkerizing or
blacking is quite acceptable for knobs, levers, nuts, bolts, and all
other non-critical iron items on the lathe. Allen wrenches are
traditionally Parkerized or blacked, as well as the grade-8 hex socket
head bolts they are used for, and I think it looks really nice. Carpet
tacks, wallboard nails, and clock springs are traditionally blued,
although the springs become colored as a consequence of the heat
treating they receive, but it is bluing nonetheless and looks really
pretty. 

These surface treatments do have a place as part of our interests and
activities. A lot of early engine manufacturers used Parkerized or
blacked nuts and bolts for the head bolts, nuts, and studs, as well as
the main bearing and rod bearing cap bolts and nuts as a way to
indicate that they were high strength. Before the marking of bolt grade
became conventional by stamping the heads with the familiar rays or
“spokes”, this was one of the more common ways the engine manufacturers
kept mechanics from getting the good bolts and nuts mixed up with the
low strength ones during an overhaul. If the low strength bolts and
nuts got used for bearing caps or head bolts the results could be
disastrous! Caterpillar solved that problem by using nothing but high
strength bolts and nuts throughout a machine and stamped all of their
bolt heads with a “C”, but they were alone in the respect of using
nothing but high strength bolts and nuts for better than half a
century. It would be interesting if someone had some information or
even did research on exactly which of the engine manufacturers used the
convention of Parkerizing or blacking head and bearing cap nuts and
bolts. If you want to try out the blacking solution you can make up a
quarter of a cup in an iron tin can like a Campbell’s soup can (not
aluminum!) using a tablespoon of lye and a like amount of potassium
nitrate (saltpeter) and gently simmer some nails or other small clean
iron objects for a few minutes in it. The black color and distinctive
luster are rather pretty. Quite beautiful, actually. I haven’t tried it
yet, but I have a good hunch that if you take some chlorine bleach and
set it outside to evaporate in a flat glass dish so it gets
concentrated that it will also work for blacking iron by simmering the
parts in it like with the lye/nitrate solution. Make sure any birds,
cats, or dogs don’t get a burnt mouth if you put some bleach out to dry
up.

By the way, speaking of lathes, I just bought a new one. I got a
Taiwan-made Jet model BD1360 lathe to replace the 65 year-old 12”x 40”
Atlas I have been using since 1959. All 1200 pounds of my new machine
are sitting out in the yard inside its shipping crate with a tarpaulin
over it just waiting for me to build a shop to put it in, and it is
absolutely killing me! I have the most interesting new toy sitting out
there that I waited twenty-nine years to buy and I can’t touch it! Oh,
Ouch! Until I get the shop built it might as well be sitting on the
moon because I don’t have any place whatsoever to put it so I can set
it up. Boy, talk about frustration! I am working on building the shop
between rain storms. I am building it from the roof down because as
soon as I get the roof done then the rain won’t stop me from working on
the rest of the shop building. Last April I bought a sawmill and I have
been sawing all my own lumber to build the shop with, so the cost and
availability of the lumber are no problem at the moment. I burn the
flitch and “lizards” (scrap) that the sawmill produces in the pot belly
stove, too, so that has been keeping me warm this winter. 

Work and play safely!

Richard Allen