By far the best hot water cleaner is Oakite, made by Oakite Products, Inc. This is one of the oldest
detergents, or grease cutting cleaning compounds, we have. It emulsifies or absorbs grease and will not
hurt hands or clothing, as it does not contain lye. The household variety is sold in grocery, and hardware
stores. Four ounces should be used to each gallon of water. There are special industrial varieties of
Oakite, which are cheap in quantity, and go further in use.
BLUING TANKS
Altitude increases water boils at a lower temperature, and as its sea-level boiling temperature of 212
degrees is none to high a heat for good results in bluing, when you are working at altitudes of 3000 feet
and more the water temperature is hardly sufficient for a good job of bluing.
All the blacking processes call for immersion of the metal parts in the actual bluing solution or in the
neutralization of chemical agents used in the process.
Stainless steel is the best tank material. These should be welded up, of fairly heavy gage sheet, about
.050" thick and one of them will be needed. The degreasing tank can be of mild iron or steel.
Tanks can also be made of black iron strip, called "hot rolled," to a size most economical for your shop.
Inside measurements for the minimum most useful size are 38" long, 8" wide and 5,' deep. Remember,
the bigger the tank, the more solution you will need. Smaller tanks, 15" by 7" by 5" should be made for
pistol and small parts bluing. It is a waste of solution and heat to use the large tank for small parts. Three
tanks of each size should be made up.
The purpose of three tanks is, one for boiling of parts in the degreasing solution, a second for the
blacking solution, and the third to hold the clean water used for rinsing.
Some type of handles should be attached to each end of the tank, and small bars or rods of metal
welded or wedged across the tank on the inside close to the bottom, to prevent the metal parts to be
blued from contacting the tank bottom.
Gas is the most common heat used, and burners for bluing are easily arranged. Long burners are
available commercially for the specific purpose; you can make them of pipe, or salvage a few old
ordinary round burners from scrapped stoves, hook them in a line and support in an angle-iron stand or
on a metal table. Propane gases are available in most areas, and the bluing setup can be operated
from a propane tank, such as is used on your barbecue. A wooden table with a metal top can be used
as well or better. If you make up one, the burner apertures and flame adjustments are not the same for
all gases. The bottled gas uses smaller apertures and burns with a shorter and hotter flame than natural
gas.
Use two parallel burners, each made of a 38" length of 3/4" pipe with holes drilled 3/8" apart in a
straight line for the individual gas flames, preferably with the gas entering each pipe burner at the center.
This is for one tank only, with the two pipe burners spaced about 2 112" apart. The tank is centered over
the two.