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Quenching in denatured alcohol


#1

Hi all.

A few years ago a friend suggested that, when annealing silver,
quenching in denatured alcohol rather than water produces better
results. I’ve been doing it ever since, but he didn’t know why or
how it worked. The quenching process is much slower than with water
and leaves a pink sheen behind. Can anyone explain what’s happening
and whether there is, in fact, a real advantage?

Thanks!
Allan Mason
Silvermason.com


#2

I’ve never quenched in alcohol but I do remember past posts about
very tragic burn incidents with the alcohol catching fire.

J. S. Ellington


#3
    I've never quenched in alcohol but I do remember past posts
about very tragic burn incidents with the alcohol catching fire. 

Useful stuff but, 2 other things.
Alcohol can burn with no visible flame
Regular (rubbing) alcohol when burned produces carbon monoxide

Tim…


#4

Quenching in alcohol sounds like a VERY bad idea…I only quench in
water, and even then after it has cooled down a bit. A very violent
reaction could (and often does) occur when quenching hot. I see no
advantage, but I could be wrong.

d-


#5
Quenching in alcohol sounds like a VERY bad idea....

I quench in water and some oils depending on the metal, alcohol is a
really bad idea. You could loose your eye browses in a sudden flash
or worse. I do ornamental metals and Damascus steel, if I don’t
quench in water, I use a mixture of oils and ATF, which on occasion
you have a flash from the vapors. Dangerous work if you haven’t had
the right training.

Jerry


#6

The only reason to quench in alcohol is to have a slower cooling rate
than water offers. This can be useful if you are quenching alloys
that are prone to cracking if they cool too fast. Typically this is
really only necessary for some white gold alloys and some tool
steels. For silver it will actually give you a slightly harder
material than you would get if you quench in water but it probably
would not be noticeable in working it.

Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160


@James_Binnion
Member of the Better Business Bureau


#7

Hi Gang,

Quenching in alcohol sounds like a VERY bad idea....I only quench
in water, and even then after it has cooled down a bit.

The main reason for quenching in alcohol is to get a slower cooling
rate. The heat transfer rate is slower in alcohol than in water so
the thermal shock to the item being quench isn’t as great. I’ve
never delved into it’s effect on grain growth.

If the proper container is used for the alcohol there’s very little,
if any danger. I use a glass dish about 2 1/2" deep x 4" in
diameter. The dish has a glass lid that overlaps the sides of the
bowl. I’ve had the alcohol catch on fire a time or 2 but not from
the item being quenched, but because I got the torch too close.
It’s a simple matter to but out the fire, just put the lid on the
jar. It’s actually called a ‘glass alcohol cup’. They’re available
in several sizes. I got mine from Progress Tools in LA,
progresstools.com . Usual disclaimers, just a satisfied customer.

Really all it takes is a little forethought, & knowing what you’re
going to do if the alcohol catches fire. As one of my old manager
from a previous life used to say, ’ Plan your work & work your
plan’. It works for me!

Dave


#8
Quenching in alcohol sounds like a VERY bad idea ... 

Not really. Unless the item is RED hot (which is improper quenching
anyway), it’s in no danger of setting the alcohol aflame. And you
should always quench both fast and deep to avoid splash.

As for whether or not it’s better to quench in alcohol than water
… I’m pretty sure there was a previous discussion about this on
Orchid, though it was a few years ago. If I remember correctly, the
most knowledgeable responders said that the efficacy of quenching in
alcohol depends on the metal being quenched. Apparently, it is more
effective than water for yellow gold, but less effective for white
gold. I don’t remember if silver was ever discussed. Maybe someone
else will have a clearer recollection of this thread than I do, or
perhaps you can find it in the Orchid archives.

Beth


#9
    The main reason for quenching in alcohol is to get a slower
cooling rate.  The heat transfer rate is slower in alcohol than in
water so the thermal shock to the item being quench isn't as great.
I've never delved into it's effect on grain growth. 

Grain growth occurs on while heating up or while holding the item at
annealing temperatures. Once you begin to cool, the grain growth
stops unless the cooling rate is very slow (think furnace cooling)
if you were not at the peak temperature long enough. Grain size is
mostly a temperature issue, once you get an item to a given
temperature the grains will only grow to a size permitted by that
temperature. The time that it takes for the grains to reach maximum
size for that temperature is determined by the physical
characteristics of the metals and the temperature you are holding it
at. The higher the temperature the faster the grains will grow and
the larger they will be. This is why annealing at too high a
temperature is a problem, the grains get so large that the working
characteristics of the metal are affected. It loses strength because
of the large grain boundaries and can crack or fail during forming
operations. Grains are made smaller only by cold working of the
metal.

Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160


@James_Binnion
Member of the Better Business Bureau


#10
   The only reason to quench in alcohol is to have a slower cooling
rate than water offers. This can be useful if you are quenching
alloys that are prone to cracking if they cool too fast. 

Hi all. Thanks for the responses. Would this then be beneficial in
quenching a mixed-metal piece, silver with copper or brass? As to
safety, I always let the piece cool a little, and have never had a
fire problem. And since the quenching process is less explosive than
in water, it almost seems safer in some way. But Jim Binnion seems to
be saying it’s not worth the trouble in general for silver. I’m
rethinking…

Allan Mason
silvermason.com


#11
  The only reason to quench in alcohol is to have a slower cooling
rate than water offers. This can be useful if you are quenching
alloys that are prone to cracking if they cool too fast. Typically
this is really only necessary for some white gold alloys and some
tool steels. For silver it will actually give you a slightly
harder material than you would get if you quench in water but it
probably would not be noticeable in working it. 

The alcohol quench is also traditionally recommended with rose golds,
especially those with only gold and copper, which are otherwise prone
to forming ordered array structures, and which can sometimes crack if
quenched in water. Failing to quench can be even worse, so the
alcohol quench is useful. Plus, the thin film of alcohol vapor that
surrounds the work as it chills during quenching is a highly reducing
atmosphere, so surface oxidation is reduced. That seems especially
useful with the aformentioned nickel white golds. At least that’s
been my experience with it. Be sure, if quenching in alcohol, to have
enough liquid that you can plunge the metal entirely below the liquid
surface. That provents hot metal from being in contact with air and
it’s oxygen at the same time it’s in contact with the alcohol vapor.
quenching too slowly is how you occasionally can manage to set the
alchol on fire, especially if you are in so much of a hurry that you
quench before the metal has quite cooled enough to just loose the red
glow… And be sure that your container is on a solid footing, and
cannot be tipped over by accident. setting the jar’s alcohol on fire
is not generally a problem, as it burns lazily enough while you reach
for the lid, cap it, and put the fire out. Being startled by a flame
up, tipping over the jar into your bench pan, while it’s burning, is
a whole new level of excitement indeed. Not recommended for amateur
pyromaniacs… :slight_smile:

Peter


#12

Experienced enamelists who do “torch” enameling find that quenching
in alcohol saves them time and work. After the enamel piece has been
fired from beneath and the torch turned off, the piece is lifted with
a spatula and carefully flipped (enamel side down) into a glass dish
filled with an inch or two of denatured alcohol and a lid placed on
it. The piece bubbles and cools–AND the alcohol cleans all the fire
scale off the copper! Amazingly the enamel stays fused. You wipe off
your piece and get it ready for the next firing. You can accomplish 4
or more layers, add decorations and do schrollwork and never need to
pickle the enameled copper piece by using this method. Of course, you
must use safety measures like avoiding splashing the alcohol and
having lots of ventilation where you are torch enameling.

Vi Jones in the beautiful Pacific Northwest