doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Nitre bluing salts

What do nitre bluing salts actually contain ? I want some but cannot find anyone in Ireland who stocks them, postal restrictions means i cannot buy them from the UK.

So can i go to a chemists and ask for whatever chemicals these salts contain ?

Bonny the big clue is in the name "Nitre" this being Nitrate and many Nitrate salts will work though the common one's are Potassium or Sodium Nitrate. They can be used as purchased but there is one big drawback if you spill any of these pure hot melted oxidising salts on to any thing other than stone brick or concreate it will burst in to flame that also includes your good self. Some mixtures have other salts added to reduce the bursting into flame like Sodium Hydroxide, Sodium Chlorate if it is spilt, but they will not stop the 3rd degree burns you will have if you spill the hot salts on yourself. Just like to say that Sodium and Potassium Nitrate also Sodium Chlorate are used in the manufacture of DIY explosives and you do live in a country that asking for such things in a Chemist's shop could raise more than an eyebrow if you get my meaning. Best try Garden or Farm supply companies rather than your local Chemist

I don't know a thing about what's available in Ireland, but if it were in the US, I'd check at a garden shop for 'stump killer'. Damascus explains what ingredient to look for on the label.

Damascus, true enough, anything "nitrate" seems to be banned, fertilizers, gardening products etc. I suppose i will have to accept rust or caustic bluing, but nitre blue looks great on screw heads.

Bonny there is a method to use for getting that look of Nitre bluing on small parts like screws etc. Though I feel that in your situation it may be just as impossible to obtain as the rest of the chemicals. You need to bring the parts you want to blue to a good polished finish, then dip them in a 50% Nitric Acid and water solution for about sixty seconds then heat slowly in a flame until you obtain that blue colour you want.

damascus,
That works well, for me, without the nitric acid solution. I just dip in oil when the color satisfies me. For other parts, I stop the color at "straw" as desired. This is very convenient, when repairing only one screw head, or replacing only one.
Mike

That has worked well for me, too, Mike.

SRH

Don't know what is available in Ireland, but the garden shop might have niter fertilizer for the lady's roses.
It is only about 16% nitrogen, but seems to work at about 6-700�F.
Chuck

Nitre bluing is nothing more than heat or temper bluing. All the Nitre salts do is to provide a �bath� held to a specific temperature so that the temperature is uniform around the part (no hot spots or cooler spots). But this can be easily accomplished with a flame or in a high temp oven. Potassium nitrate is a good medium because of its working range (300-1000 deg F) and it�s very soluble in water so it�s easy to clean up.

Nitre bluing usually refers to a molten bath of potassium nitrate or saltpeter, as Mike Hunter and damascus have pointed out. The working temperatures are very high, and extreme caution must be used. Even simply heating a pot of solidified potassium nitrate can cause an eruption of extremely hot molten salts as pressure builds up beneath the still solid surface. It is recommended to leave a large screw or bolt in the bath to then later remove when reheating in order to provide a vent hole.

Saltpeter used to be available in grocery stores in the spice section, because it was used in pickling and food preservation. Some stump removers do use a high concentration of potassium nitrate, but you have to read the label.

In case the nitre bluing salts you were inquiring about were for regular hot salts or hot tank bluing, here is a recipe for homemade bluing salts. The Brownell's "Gunsmith Kinks" books have a lot of very useful information on all types and methods of bluing.

5 pounds 100% sodium Hydroxide (100% Lye)
4 pounds Ammonium Nitrate (Sodium Nitrate may be used instead)
1 gal. Distilled water

This is a very caustic mix that is used in a steel tank only.
The Lye must be pure 100% like "Red Devil" or the kind used for soapmaking
It is for steel bluing only and it will not Blue Winchester 94 Receivers.It works Identical to Brownells Bluing salts.
Temperature range is around 260 to 275 deg F for the boil to blue the parts. Hot caustic bluing is also very dangerous as the solution will cause very nasty chemical burns or blindness if it splatters onto your skin or eyes. Learn all you can before trying to do it, and wear appropriate safety gear.