alternitive to salt bath ?

[paul harm]

if oil has a flash point of 450 deg.-couldn't a tank of heated oil be used instead of salt for a low temp. bath ? seems it would be cheaper, and less problems. another question, how would one heat the oil ? it seems you could go right from non-magnetic in the forge, to the headed oil. if left long enough, would it be martempering ? my understanding is that this would give a very tuff blade. Ed, your thoughts please [ and anyone else] paul

[Laredo7mm]

I think low temp salt set ups are relatively cheap compared to high temp ones. I think most people just use a plain low carbon steel tank for their low temp salts and heat it with a burner or electric.

I do believe there are oils for marquenching and austempering, but I would be scared of having a fire with that much hot oil around.

Just my $0.02, I am sure the others can shed more light.



Edited to add:

Here is a link to Heat Bath, they sell salts and oils for HT. If I am not mistaken, I think Kevin Cashen is now a distributor for them. It is either Kevin or Tim Z.

Heat Bath

If ordering from Heat Bath directly they have a min purchase of 400 pounds. That is why I have never bought any of their stuff, eventhough they are located in Michigan.

[Sethhoward]

I was thinking like you and ordered some of the Marquenching oil from Heatbath as well as there Parks # 50 ( which is awesome ) . I found not much difference in the Low temp salts or the oil in heating time as the oil is very thivk at room temp. The oil was faster however. The big difference was the smell. My Whole shop smelled like burnt motor oil for a while.

You can order smaller amounts from Heatbath ($100 min ) if you have the right contact person. If anyone wishes the contact name post here and I will look it up. I am not on my PC right now or I would go ahead and post it.

Seth
SethHowardKnives.com

[Ed Caffrey]

Using oils would not be my first choice, for the reasons that Laredo mentioned. That's not to say they can't be used, I just have visions of 3-5 gallons of oil buning my shop to the ground. I'm sure there are safe oils out there for use, but I've never researched or tried them. Nitre blue is so easy and safe to use.......I've not considered anything else.

[paul harm]

thanks for the replys- what is nite blue, and are there any older threads on low temp. salt baths ? paul

[Sethhoward]

Nite Blue are I believe the bluing salts from Brownells. Even if they are not the salts from Brownells will work perfectly. That is what I use. One bucket was all I needed BTW.

Just get a pan or tube, ( I use a stainless 4X4X18" pan I picked up at a resturant supply ) and heat it to 400f or so with a propane burner or electric hot plates and presto, low temp salts.


Seth

[Ed Caffrey]

Nitre blue is what Brownell's sells as a low temp bluing salt. It comes in a bucket, in granular form. You simply put it into a sturdy container and heat it. It melts at 300F and has a working range from there to 900F.
Here's a link to it...... Nitre Blue

I like it becasue it can pull double duty as a low temp salt bath, and bluing.

[paul harm]

sounds good- i'll contact them- thanks paul

[foxfyre841]

This is an old thread but thought i should mention this for anyone searching for this subject: Nitre Blue salts are the same as a certain brand of stump remover. Many gunsmiths just find the stump remover, it's a bit cheaper and may be available locally. Google the two terms for more info.

[jdm61]

I have never used salts because I can't right now, but remember this. if you are using steel that needs Parks #50 to quench quickly enough, then you are not going to be able to use low temp salts for the quench. However, with that said, it looks like Howard Clark heats his clay coated 1086m blades in high temp salt (making sure to "bake" the clay at 600F in the oven to dry it out first...his recipe..I e-mailed him) then quenches them in some kind of fast quenching solution, (water or polymer i think) and then puts them in the low temp salts. Don't know whether he is tempering in the salt. I'll have to ask next e-mail. I am anxious to check out this new Crucible forging steel because it sounds like it combines the best features of W2 and 52100 into one steel....the fine carbides and resistance to grain growth of vanadium and the ease of quench, etc from the chromium.