for those who like to do there own gun bluing.found a cheap source for lye, Sential Depot --866-840-2495,64 pounds for 107 bucks and that includes freight,it is food grade and Kosher certified,have been smiting for over 40 years and best found yet.we blue 5 to 8 guns a week and have not changed tank in 2 years-----------------------------have much fun

I always like my guns to be Kosher

Lye is Sodium Hydroxide.

Crystal Drano is the same although not Kosher

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Still Running Against the Wind

You need 'clean' sodium hydroxide for home made bluing salts.
Drano and a few others have 60+% of it which is good but they add small amts of aluminum (chips) to the dry ingredients.

That's to make it bubble and foam when it mixes with the water and gunk in the drain.
Makes it look impressive to the cleaning process,,maybe it is , I don't know. It's the aluminum simply being consumed by the lye/water solution.
Same thing happens when someone puts an aluminum gun part into the hot salt bluing tank. Bubbles and foams and no more gun part..
The consumed aluminum has then contaminated the salts as a bluing solution.

Used to be able to buy Red Devil brand lye in the grocery store. Pure stuff,,or as pure as was needed both for clearing drains and for making bluing salts. That stuff has been pulled from the shelves AFAIK. Dain'gious.

The lye and sodium nitrate (or ammonium nitrate,,fertilizer grade is OK,,,or potassium nitrate--stump killer from the garden store works) is the bluing salts.
Buying any of the nitrates in big quantity can raise some eyebrows too these days. Can't do nothin' anymore but smoke dope is OK I guess.

It takes quite a bit of dry ingredients to make a gallon of bluing mixture.
IIRC,, 5# of lye,,2 or 2.5# of the nitrate and one gallon of water.
**Lot's of heat generated during the mix as well as gases.
Careful,,and have a set plan on how to mix and what order ect.