Today there is little said about the quality of the water in the slack tub (where the blacksmith quenches hot metal), other than it is not fit to drink.

Several folks have suggested that you just fill the slack tub with tap water and let it sit for a while. But the old blacksmithing books call for "soft rain water" as a quench.

Does it matter?
Which is better?

I know nothing about which is better, but my question is, how can you tell? What kind of tests would you perform?

Yes, it makes no appreciable difference. Brine will quench faster than water, but should only be used in those applications where you need that. With nothing added to the mix, water is water.

Where can I get rain water?

rain dance! :D

Buy an UMBRELLA Rich and, "it will come".

Tap (mains) water is not pure water. Depending upon your locale, it may be 'hard' -- have minerals dissolved in it. This is what makes limescale. In some areas, chlorine, fluoride or other chemicals are added to water for various reasons.

In old times there were a lot of people who had odd beliefs in what would work best for quenching---"Sources for the History Of the Science of Steel" C.S.Smith has a lit of them from the 16th century that includes radish juice and worm water.

Pretty much everything that is drinkable to start with will have the same quenching effect. If you have real hard water you might get a light white deposit on the piece, especially if you take it out of the QT before cold and the water dries on it. Doesn't affect the steel though and a wire brush will take it off with no problem.

Generally I'll fill my bucket from the hose and pour it on the tree shading part of my shop on the west side when I'm done---want to encourage that tree! I've used rain, river, creek, bottled, etc water and never noticed any real difference.

Now Ocean water might make a difference!

My dog says the slack tub is very drinkable! If I let him get too much access, I have to keep refilling it. However, I take no special cares for the quality of the water, just dumping it out and replacing it when it gets disgusting, or frozen. My steel needing a good quench is usually oil-quench steel. For that, I use a mix of corn oil and olive oil, which I also use to blacken any cooking or eating implements that I make. This way I feel better about eating off of them.

we got a big ole well...so thats rain water only filtered!!

Fat Pete

Buy an UMBRELLA Rich and, "it will come".

Actually, it won't but if you plan a day at the beach or wash your car, it will!;)Dan

I was reading The black smith's Craft by Charles McRaven and he mentioned a story about am early settler smith who had some guys who claimed they had the best mixture for quenching quicker and mixed it for him. Gave him the recipe but didn't do any good because he couldn't read it, but somebody did and said it was just salt in the water, is that actually a ways to go about quenching?

Where can I get rain water?

Rich, Ya gotta melt some snow! Oh, wait. Never mind :D

I use rain water because I dont have a tap out by the smithy. That and its free:)

Drogo, according to one website WV was the only state that had less water area than NM---of course we have a LOT more land area than WV.

What is this "rain" you mention? we haven't had a rain that would do any good filling a bucket in a couple of months. (hmmm installing gutters and having them automatically fill the quench tank with automatic overflow protection would be a nice conceit in damper climes...)

As I recall that story from Charles McRaven: a smith had paid another smith for the receipe of his "secret quench solution" that worked a treat but had to be made up at some expense by the local pharmacist (they didn't call them chemists for nothing), and who was also in on the scam.

The formula was "an aquaous solution of sodium chloride" ie saltwater.

Traditional receipes call for disolving salt in it till it would float an egg; probably a fresh laid one and not a factory farmed one.

Here in the Phoenix Metro area we are now getting Colorado River water and it is like thin concrete. Does it make acceptable slack tub water? Yes since it does cool the steel. It is the pits for irrigation though because after a year or so the soil is white around the trees and shrubs. We have to change it daily or leave an oil film on top because of mosquitoes. I used to raise turtles and their shell would be white from the hard water. It may make an excellent quench if you let the water evaporate and the dissolved solids concentrate.

I have rain water in my slack tub.Well, part of the year,the other part of the year it is definitely hard water.I gather it by putting my slack tub right under the leak in the roof.

Where can I get rain water?

Rich ol' buddy i could ship you some . I use rain water and well water. I am not particular as a bladesmith I don't quench in it, I just cool my tongs.

Lorelie Sims has a hint in her book stating that an oldtimer blacksmith said that the water in your slack tub would rid you of poison ivy/oak/sumac when you wet the affected area with it. A friend of hers did this and came back the next day with no rash. She didn't state what kind of water was in the tub....

I use tap water, mainly because it is easy to get and our water is not hard. I do have a galv. tub that I am fixinta set up as my tub. I don't have problems with mosquitoes either. Not sure why, we have them as big a buzzards here. I guess we are too close to Louisiana! :)