Many of the features of this website use JavaScript. Your browser either doesn't support Javascript, or you have it disabled. You will need Javascript enabled to view our complete class descriptions or use our otherwise convenient registration and email links.

If you'd rather, you can reach us directly by phone:
Mike - 617 230 9572 or Carl - 781 608 0900

Super Quench

This is a mixture that'll cost you about $7 at the grocery store and will last for years.
With it you can achieve surprising hardness AND still retain decent toughness in mild steel.
I've read old references to "slippery brine", and I suspect this idea isn't actually NEW.

This mixture was invented by Rob Gunter.


  • 5 Gallons of water in a bucket that has a lid that seals well.
  • 5 pounds of salt (these three containers came up 2oz short, the mix still works just fine.)
  • A bottle of dishwasher rinse-agent. (Jet-Dry works too, in the original recipe it was Shaklee Basic #1)
  • A bottle of Blue Dawn Dish Detergent (the blue dye turns green when the mixture finally wears out a few years from now, other colors don't help in this way.)
Mix it up well, keep the lid on it.

To use:
Give the mixture a good stir.
Get the work up to a full orange (hardening temperature for 1020 is noticeable higher than for higher-carbon steels).
Quench quickly and actively.

It won't be glass-hard, but you should find that a file does not bite well, and it'll still be plenty tough. I like this stuff for corkscrews, hardy tools, short-term specialty chisels, RR Spike knives (If you're gonna do it, y'gotta at least try to make it a decent knife), short-term or low-use marking punches.

Caution:
DO NOT USE THIS STUFF ON HIGHER-CARBON STEELS.
It will end in tears...

...and lots of cracks.