I would like to know what you guys that hot blue are using for salt and cleaner. I've been mixing my own but it seems like everytime I go to blue something lately I run into a new quirk. Changed soap tonight from one that was leaving green spots on the metal to one that looks like it is streaking (I think its the soap anyway).

I mix my own salts and don't use pre-clean. After all, automotive machine shops used to boil engine blocks to clean them in almost the same mixture of salts used for bluing. Brownells is a great company, but they're in the business of selling stuff so if they can sell you five tanks when two will work...

I use Oxynate No. 7 from Brownells.
Works great.

As for the cleaner, I used to use the Brownells stuff ( I tried to find it on their website but cant. I wanted to say 'Dicropan' but thats the wrong name.)

Anyways, they started charging a haz-mat fee so I tried using TSP and it works great.

I agree, Oxynate #7 works well, but I have to pay almost $4 a pound for it and my tank needs about 120 lbs. The salts I mix are the same formulation and cost me about $.70 per pound to mix myself. Easy decision.

There are industrial suppliers who will sell you the same bluing salts that are marketed by gunsmith suppliers. The industrial versions are cheaper especially if located close enough to pick it up your self and if you can afford to buy in large quanities.

I bought a 500 pound drum a few years back. Decanted it into 5 gallon buckets and I plan for it to last me for a very long time.

Nick, if you are getting strange colors, green overtones, I suspect you may be using stainless steel for your bluing tank. It will cause some really weird hues in your bluing. If so changing to black iron will cure your problems.

John, would you share with us the formula you are using for making your own salts?

quote:

Nick, if you are getting strange colors, green overtones, I suspect you may be using stainless steel for your bluing tank. It will cause some really weird hues in your bluing. If so changing to black iron will cure your problems.

I agree! I didnt get green colors but when I used stainless as a blueing tank I would get screwed up results. Had an iron tank made to the size I wanted and have had no problems. I use the stainless tank as a final rinse tank now.
It would be nice to have a formula as I am getting low on a big order from long time ago!

quote:

Originally posted by Toomany Tools:
I mix my own salts and don't use pre-clean. After all, automotive machine shops used to boil engine blocks to clean them in almost the same mixture of salts used for bluing. Brownells is a great company, but they're in the business of selling stuff so if they can sell you five tanks when two will work...

Thats interesting, I always thought the same thing...why do you need soap when the bluing salts clean stuff up so well? Would you mind sharing your recipe? I will post mine I just need to get in the shop and write it down so I can remember it.

Also I do not blue in a stainless tank but I do use unfiltered city water. Thing is it seems to be something else because most of the time I get superb results. I really think it is the soap.

65% sodium hydroxide
25% potassium nitrate
15% sodium nitrate

The recipe I have uses pounds. It comes out to:

Sodium Nitrate 36%
Sodium Nitrite 24%
Sodium Hydroxide 40%

Nick

I dont know about your city water but if I use city water where I live it causes lots of problems. If I use it for after bluing rinse and boil out it is garaunteed to cause discoloration and rust spots.

I learned the hard way that I have to use either distilled water or rain water.

A shop I worked at several years ago always used Joy liquid dish soap with very good results. Now I use simple green. Just spray it on, rinse with a water hose then dip it in your hot water rinse, then on to the bluing salts.

I find that bluing salts are self cleaning for mild contamination but if you have oil or grease on the parts near joints, sharp corners, engraving etc. that the bluing may not take evenly. Cleaning with soap is good insurance for all that hard work you did filing, polishing or buffing.

John

Thanks for your formula. For dummies like me, will you express that in pounds?

John, do you pre-mix the chemicals or just add them to the bath in proportion? If pre-mixing, how are you doing it? I can see myself trying to shake a 5 gallon pail enough to get everything mixed.

Where can a person buy these chemicals at without someone thinking you are making a bomb or setting up a meth lab?

I'm on a well and haven't had any trouble with using that water for the hot bluing. I have a rain barrel I use to collect water for rust bluing.

First, a word of caution: THIS STUFF WILL BURN YOU, COLD OR HOT! You must use extreme caution in handling the salts once you've added water. Dry, they're not bad but don't attempt to handle it at any time without a face shield, heavy rubber gloves and apron. Wear long-sleeve, heavy shirt and leather boots. Last year while bluing I accidentally dropped something into the tank and splashed my upper arm, above my rubber glove. Instant 2nd-degree burn and permanent reminder to carry with me.

When I change out the salts I clean out the old, which is a candidate for "Dirty Jobs" and also dangerous. I add the water I think I'm going to need and then add the salts to the water. Do not put all the salts in the tank and then add water. Seems basic but not everyone remembers their Chemistry class. As you add he salts to water you will get an exothermic reaction--the water will get warm and sometimes it will boil as the salts are poured in.

Look in the Yellow Pages for industrial chemical suppliers; they should have what you need.


Small Tank: About 5 gallons of solution

9.7# Sodium Nitrate
6.5# Sodium Nitrite
10.8# Sodium Hydroxide

Large Tank: About 20 gallons
38.8# Sodium Nitrate
26.0# Sodium Nitrite
43.2# Sodium Hydroxide

I've got to admit I'm a little uncomfortable giving out this information as it is potentially very dangerous stuff. Just a little drop in your eye will blind you. If you slip and splash the hot salts on you it will take your skin off. However, if you have training and experience working with chemicals it is not particularly difficult to do safely.

quote:

Originally posted by M Pursell:
John, do you pre-mix the chemicals or just add them to the bath in proportion? If pre-mixing, how are you doing it? I can see myself trying to shake a 5 gallon pail enough to get everything mixed.

I mix mine one big batch at a time in a cement mixer.

Good stuff here, Thanks for all information.

At one time I was able to use our city water with a filter system I bought at sears and just hooked up a garden hose, but they are useing something called Alunma or something like that and it plays hell with my salts. I use gallon jugs that have been reverse osmoses and have no problems with the water. May have to make a rain catcher, a guy can only save so many jugs for catfishing in the spring and summer!

What do you use a gallon jug for in noodling?

quote:

What do you use a gallon jug for in noodling?

John; You wont catch me sticking my hands in a hole and wandering if maybe a snake or beaver might be there instead of a fish...

We put several hooks on a line with a good weight and drift them . Jug line fishing, fun to be setting there and watch it take off or go under, chase is on!

I agree 100% with you on getting burned while blueing, so everyone be safe! I've had splatters burn me a time or two, good to keep viniger out there just in case.