Borax Salt Bath?

galadduin

galadduin

Joined
Dec 25, 2004
Messages
1,363
Here is another stupid question:
I want to HT my D2 properly and heat it perfectly even. As borax in my country is very very cheap I have tons of anhydrous borax. If I fill a SS cup with borax and let it melt in my propane forge then preheat my knives I forged then dunk them in, does it sound good? Does anyone HT their blades that way? :confused:
As I didnt heard this, I may be wrong but I couldnt see any reason not to try. It would make my life pretty easier...

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Borax : melting point 742 C
boiling point : 1575 C

D2 :
Preheat 650-750 C
hardening temprature 1000 - 1040 C
 
Emre , you are very , very strange. I have never heard of heat treating that way. The only use I can think of is a flux for making damascus.
 
I don't think I understand ,Are you planning on using the Borax for the quenchent or as a medium to bring the blade up to critical. If its a medium to bring the blade up to critical, I believe your going to have a messy bunch of quenchent when your done, but what do I know. Sounds interesting to say the least.

Bill
 
I think he's talking about using the borax as a salt pot for austenitizing and it should work if he can control the temp well enough. No decarb, plus he can use an oil quench, and if that's messy then D2 is air hardening anyway. A little unconvention but many of the best knifemakers are.
 
Just remember that borax at high temps is very corrosive. I know it will eat away 1095, but I am not sure about D2. Just something to keep in mind.
 
Thanks fo comments. I will use it today as a salt bath and I will post the results soon. Wish me luck... :D
 
I think I thought he was asking about using it as flux. My first glance was as a atmosphere control and that is what attracted me to look.

RL
 
My take on this is that it won't work.Besides that it will be very dangerous.The hot borax will eat up the blade and probably mess up the forge.Liquids at those temperatures require very different handling.A salt pot is far more complex than heating up a container of salt.My advise to anyone who does not have extensive heat treating experience ,and is considering a salt treatment,would be to send it to an expert.Dead or maimed is a bad way to be. - Stacy Apelt
 
Ok,
Thats how it happened.
2 days ago I put one pound borax in a Stainless cup and let it all melt in my forge. Borax didnt spill or anything dangerous happened. The whole borax melted almost in 15 mins. Then I pre-heated the blade and put in the cup. I realized the borax doesnt have enough viscosity to use it as a salt bath. The blade didnt sink :grumpy: . But no problem, I then covered all the blade with borax, let it soak at around 1000 C. When the soak time finished I scraped borax from the blade with a chisel. Quenched in forced air. It went ok and no scale.

OK. I admit, the borax bath idea wasnt so bright, but was worth a try. If it had enough viscosity that would be very simple solution to my HT problems.
I think all of us are somekind of scientists. I am sure you all experimented some in the past. So I am not regretful. I experiment everyday something new, with chemicals, methods, safety, HT etc..

Thats the only way you can make a difference.
 
galadduin said:
Ok,
Thats how it happened.
2 days ago I put one pound borax in a Stainless cup and let it all melt in my forge. Borax didnt spill or anything dangerous happened. The whole borax melted almost in 15 mins. Then I pre-heated the blade and put in the cup. I realized the borax doesnt have enough viscosity to use it as a salt bath. The blade didnt sink :grumpy: . But no problem, I then covered all the blade with borax, let it soak at around 1000 C. When the soak time finished I scraped borax from the blade with a chisel. Quenched in forced air. It went ok and no scale.

OK. I admit, the borax bath idea wasnt so bright, but was worth a try. If it had enough viscosity that would be very simple solution to my HT problems.
I think all of us are somekind of scientists. I am sure you all experimented some in the past. So I am not regretful. I experiment everyday something new, with chemicals, methods, safety, HT etc..

Thats the only way you can make a difference.
Click to expand...
........................ ;)
 
galadduin said:
The blade didnt sink :grumpy:
Click to expand...

Interesting... if it melted that supposes it went to liquid, if liquid and the blade didn't sink, that makes it heavier than steel, which I'm pretty sure borax isn't, Just how thick a liquid is melted borax?


galadduin said:
I experiment everyday something new, with chemicals, methods, safety, HT etc..

Thats the only way you can make a difference.
Click to expand...

I agree with this, most Breakthroughs weren't invented by ppl following a step by step plan but rather by ppl playign around in a lab following tangential thoughts...
 
It didnt sink because It was like a jelly not so liquid at all.
I'll keep on experimenting. You'll hear when I explode or poison myself :D .
 
Though borax starts to melt around 800 C, it boills at over 1500C. I'm guessing the viscosity may decrease enough with temperature to let your blade sink if you went a bit over 1000 C. But, I melt metal all the time under borax at around 1000C ad it doesn't have any trouble sinking. Would it be so hard to hold your object under the borax, either with force or some kind of weighting mechanism, maybe its more trouble than its worth. At any rate, a hot bath of dilute acid like sodium bisulfate (used for pH adjustment of swimming pools) will take off solidified borax glass in a jiffy.
 
Guido, thanks for the advice. Yes it is more trouble than its worth i think. May be I will try to force it with a piece of iron. More possibly I wont. But borax doesn't harm D2 or SS (at least in the soak time). This was a valuable experience for me. I figured that I can use borax for any reason (coating to prevent scale, bath, etc) safely with this steel.

Also the floor of my forge is covered with cat-litter. For forge welding I plan to put a sheet of SS between Cat-litter and kaowool to protect the forge. You know, I couldnt find any ITC 100 or any similar to coat my forge lining in my country.

Wish me luck. I will try to make some damascus billets for the first time as soon as I finish the Reed-Knives, out of L6 and 1085.
 
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