Subject: Hard Data from Robb Gunters Magic Quench

From: "Franklyn Garland" <[email-masked]>
Date: Fri, 12 Jul 1996 17:01:34 +0000

Greetings all!!

I may be able to shed a little light on the super quench debate (does 
it work or not?)

I dug up my letter from Robb Gunter about his super quench solution.  
It makes a pretty interesting read.  There are several tables etc 
that I need to scan in, but this data ought to be of some interest 
to many of you.  It is a comparison of 1018 steel, 1" round stock,
4" long  heated and quenched at various temperatures in cold brine,
NaOH and super quench.  I have included only the data from
 quenching  at 1500 degrees farenheit.  Hardness listed is in the 
Rockwell "C" scale, three samples per cycle.

Cold Brine (10% brine frozen to a slush)
     44.0 +/- 1.6
     44.0 +/- 1.7
     45.0 +/- 0.3

10% NaOH Solution (room temp)
     43.0 +/- 2.8
     44.0 +/- 3.0
     45.7 +/- 1.4

Super Quench (room temp)
     44.7 +/- 1.7
     43.9 +/- 1.9
     43.8 +/- 1.3

As you can see, the brine slush actually did better, hardness wise, 
than superquench or NaOH.  The only test (not shown) where super 
quench finished out on top was in tensile strength.  Robb said that 
under a microscope the crystals were all "racked".  Interesting Eh?  
The Super quench, at room temperature, performs well without the 
hazards of NaOH solution or the hassels of frozen-slushy-brine.

Make of this what you will, but this was supplied by Robb Gunter 
himself.  He says, "I am most interested in the fact that the correct 
and accurate information is disiminated."

=================================================
Franklyn D. Garland                         
The Celtic Knot Forge                       
[email-masked]                                 
http://www.mcs.net/~frnklyn/homepage/
For Public PGP key, finger [email-masked]
=================================================

---

From: [email-masked] (Dan Hughes)
Date: Mon, 15 Jul 1996 10:54:48 -0400

>>Cold Brine (10% brine frozen to a slush)
What was the hardness before the heating and quench and what was the
hardness with a water or oil quench?

---

From: "Franklyn Garland" <[email-masked]>
Date: Tue, 16 Jul 1996 18:08:41 +0000

On 13 Jul 96 at 11:34, MR WILLIAM A HOCHELLA wrote <snip-snip>

> To All,
> Please read "Tool Steel - Seriously" first.
> Being a Metallographer by first love, I have not come across the
> term "racked"

Sorry about that.  "Racked" is my term because I couldn't remember 
the name of the geometrical shape he called it.  Racked comes from a 
construction term, as in, "That building is racked," or 
tilted/twisted off to one side.  Sort of a parralellogram, I guess.

>. 10% brine is not supposed to be used in a state
> resembling a slush puppie.

I think you may have missed my point.  Wether someone uses this 
superquench stuff or not is entirely up to them.  The testing was to 
see how hard, via how fast a quench, mild steel could get.  10% brine 
slushy may be unorthodox but it did produce some appreciable 
hardness. A Rockwell of mid-40ish is pretty good for many short run 
tools.  If you use the tool a lot, make it out of good steel.  If you 
need a fuller or even a simple stamp for a particular job, it is much 
nicer to pull a piece of scrap 1018 out of the bin, shape it and 
harden it to the 40ish Rockwell.  Then go do the job.

The whole idea for a lye quench or superquench came from a turn of 
the century blacksmithin book that Robb had found.  It was comparing 
mild steel to the old wrought stuff and pointed out this advantage 
for use in short run tooling.

Does anyone besides me feel we have beat this topic to death yet?

wishing you all well

---

From: [email-masked]
Date: Wed, 17 Jul 1996 18:43:30 -0400

To All,
The hardness of the 1018 1" round stock has no relation to the hardness after
hardening. 1018 HRS should test out in the middle Rb's. (memory only)

Hochewa