First Try At Hot Bluing

kvt

kvt

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Well pulled my first try at hot bluing out of the old oil last night. To me it seems to look ok.
Had to make some small knobs so I thought why not protect a little bit and try something new. Even got a set of cheap stainless steel pans to use for things like this (wife did not like me using her kitchen stuff). Mixed everything up and boiled it for about 30 MIn or so, then rinsed and put in jar of old oil My photo skills are lacking but here is what I got. 001.jpg 003.jpg
 
Hi Ken,

Looks great!
Are you going to share your recipe?

I always thought pyrex glassware would be the least "accidentally reactive" vessels for this. Thoughts?

Thanks,
-brino
 
My bluing vats are 10ga. welded steel. I use sodium hydroxide, potassium nitrate and potassium nitrite. 75%, 15%, 10% by weight. Start with a nearly full tank and heat until the salts all dissolve. Stir with a long iron rod to aid the process.Temperature should be about 250 F. Run bailing wire thru the long hollow parts and place the small stuff in an iron (not stainless) wire basket. Continue heating and monitor temperature. Look at the parts from time to time. When they are dark, remove them. Dip in clear water. It will sizzle so be careful. Then an oil bath.The harder metal will blue at 280-290. Dead soft takes 300-305 with new salts. As the salts get tired,(used up), the heat will be higher.Caustic this hot, (think molten salts) will eat organic stuff,like shoes, skin and meat immediately!!! NO GLASS CONTAINERS SHOULD BE USED! If you were to drop a part and it broke the glass you wouldn't be able to get enough water on it fast enough to avoid major heat and chemical burns.Wear eye protection, gloves and a heavy rubber apron. I blue regularly in my shop and I still get stupid and ruin a pair of boots every so often by dripping a tiny drop on my boots. "But I was just looking at the progress of the process" is a poor excuse for a burned foot or worse. Foundry work is handling molten metal and we all know that's hot. 300 degree caustic is worse!!!!!! It just doesn't "look" like it would cook you alive.
Your parts look black. Very well done, now to see if they fade with time..........How hot did you cook them?
 
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Now I see them.
Those look great.
Definitely share process and recipe.
 
Thanks all, I think I could of polished the metal up a little better to get a better finish on them.
Here goes, Took 1 LB of 100% Sodium Hydroxide (lye) http://www.amazon.com/Comstar-Pure-..._5?ie=UTF8&qid=1429629622&sr=8-5&keywords=lye (purchased extra as use it to clean Alum before Anodizing).
1/2LB of 100% Potassium Nitrate http://www.amazon.com/Spectracide-6...&qid=1429629582&sr=8-1&keywords=stump+remover This was the only stump remover that was 100% potassium nitrate and was still cheaper than buying Potassium Nitrate by name only took Half of it)
6cups of Distilled water
WORK OUTSIDE.
put water in steel or stainless steel pan, add lye slowly to much at once can cause it to boil over. It will heat up as it dissolves. use a wood or stainless to stir it, Plastic can melt (it did), Once that has fully you can start adding the Potassium Nitrate, again slowly. Once all dissolved, put on a burner, I used an outside burner used for turkey fryer/Crab Boil/Crawfish boil, get to a nice boil, then place clean dry metal in the pot. The finish will depend on how clean and how polished the metal is prior to putting it in. (I ran small parts through the dishwasher then only handle them with clean rubber gloves and towels etc) Watch water level as you may have to add some additional water, If you do be carful. Note: different alloys will take at different rate and color. (but have not tried that yet). Boiled for 30 to 40 Min or until color was what I wanted, Then pulled out and rinse in more distilled water. Then dry off and place in some old used motor oil. Some say 30 min, others over night. I did the over night.

I let the solution cool down and it started to turn into a mush, I then took and put it into glass jars with plastic over the tops before putting the lids on, to store it for my next use. All I have to do is dump it out add a little water and go at it again. I figure that I will eventually have to add more chemicals to it.

AGAIN I Stress use safety gear and work in well ventilated area. This is an acid base and is very dangerous, and the fumes are not good for you.
 
kvt said:
This is an acid base and is very dangerous, and the fumes are not good for you.
Click to expand...


This is not an acid. Caustic is sodium hydroxide. Lye!11 Very basic. Ph around 11. Acids are Ph lower than 7. Battery acid, sulfuric acid is Ph 1. Acids burn the surface of your skin. Lye goes right to the core. If you get this mixture (bluing salts) on your skin wash it with vinegar, a very mild acid to neutralize the lye.
 
Those are nice !! I've seen much worse blueing jobs than that.
 
Ph of Lye"NaOH" is more like 14 I think. It's a strong base. Your bluing looks great, Cactus!
 
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