Just bought a very cheap paragon sc2: question about viable as a heat treat oven.

[Smurf masher]

This is the model:

Paragon SC2 Glass Kiln - FREE MAINLAND UK DELIVERY

A value tabletop kiln for glass fusing and slumping. Great for jewellery and smaller glass work. Built by Paragon Kilns in the USA. A good looking design with a simple programmer full of pre-programmed schedules to get you going, the Paragon SC2 is a good choice if you are looking for a...

warm-glass.co.uk

I got it very cheap on Ebay. So cheap that worst case it can be used as a toaster oven for tempering or for cooking my stablized wood.

But I really got it as I'm only going to be making sub 12" knives and the max temp on it is 2000F or 1093c. Which appears to be good enough for annealing stainless steel.

I know I'm trying to run before I can crawl (i've made 2 knives) but I plan to try stainless damascus with stainless foil/argon and heat treat it with this little kiln. Diagonally I can just about fit a 11 inch blade, add an angle upward and I can get 14 inches. (yeah its tight... 20cmx 20cmx 14cmH.

Will this work as an early tryout unit? One that I may well replace once I get more funds. And yeah... I erm... bought a load of M390 super clean direct from Boehler.

Which has the following heat treat guidance.


Heat treatment recommendation
1.030 °C/–80 °C/2 x 250-350°C
for best corrosion resistance and toughness;
goal hardness 56 – 58 HRc
1.030 °C/–80 °C/2 x 495-525°C
for balanced wear resistance,
hardness & toughness;
goal hardness 58 – 60 HRc

I've also got a load of AEB-l, elmax, 1095, 15n20, and 403 stainless. I was going to try a san mai in AEB-l 403 damascus with the m390 as the core. (yes I know it is hard, but I'm happy to fail 20 times before I get it right) I'm also going to build a mcdonald rolling mill using an old slow geared winch motor.

Do I need to do the cryo stage? And if so How the heck do I get liquid nitrogen, and avoid freezing my face off. Pics of my first knives are below.

 

[Brad Anderson]

This is the model:

Paragon SC2 Glass Kiln - FREE MAINLAND UK DELIVERY

A value tabletop kiln for glass fusing and slumping. Great for jewellery and smaller glass work. Built by Paragon Kilns in the USA. A good looking design with a simple programmer full of pre-programmed schedules to get you going, the Paragon SC2 is a good choice if you are looking for a...

warm-glass.co.uk

I got it very cheap on Ebay. So cheap that worst case it can be used as a toaster oven for tempering or for cooking my stablized wood.

But I really got it as I'm only going to be making sub 12" knives and the max temp on it is 2000F or 1093c. Which appears to be good enough for annealing stainless steel.

I know I'm trying to run before I can crawl (i've made 2 knives) but I plan to try stainless damascus with stainless foil/argon and heat treat it with this little kiln. Diagonally I can just about fit a 11 inch blade, add an angle upward and I can get 14 inches. (yeah its tight... 20cmx 20cmx 14cmH.

Will this work as an early tryout unit? One that I may well replace once I get more funds. And yeah... I erm... bought a load of M390 super clean direct from Boehler.

Which has the following heat treat guidance.


Heat treatment recommendation
1.030 °C/–80 °C/2 x 250-350°C
for best corrosion resistance and toughness;
goal hardness 56 – 58 HRc
1.030 °C/–80 °C/2 x 495-525°C
for balanced wear resistance,
hardness & toughness;
goal hardness 58 – 60 HRc

I've also got a load of AEB-l, elmax, 1095, 15n20, and 403 stainless. I was going to try a san mai in AEB-l 403 damascus with the m390 as the core. (yes I know it is hard, but I'm happy to fail 20 times before I get it right) I'm also going to build a mcdonald rolling mill using an old slow geared winch motor.

Do I need to do the cryo stage? And if so How the heck do I get liquid nitrogen, and avoid freezing my face off. Pics of my first knives are below.

LOL. Just dive right into the murky waters, from the high board, at 90 MPH with your hair on fire!

-The oven looks fine for heat treating stainless blades as long as it works and the temps are accurate.
-I would stick to a blade length that you can center in the oven (10"). Don't forget you will need a foil envelope on them as well, which adds to the length.
-I doubt you will be forge welding stainless in it as I think you will need to get the steel much hotter than 2000F to do it (2400-2500F area??). (although I've never researched/attempted to forge weld stainless and I'm just taking an educated guess).
-Although not absolutely necessary, LN2 when used properly as an extension of the quench, helps to eliminate retained austenite in stainless blade steels and usually results in a few extra initial points of hardness on the RC scale.
-To deal with LN2 properly, you need a dewar (not cheap, especially the ones with a large mouth that are desirable for a bladesmith).
-Ln2 can be obtained from most major welding gas suppliers. I'm sure there are other sources but that is where I get mine.
-To avoid freezing your face off, don't stick your face in the dewar I would recommend safety glasses, a face shield, and a pair of welding gloves, as well as common sense when handling it. LN2 is roughly -320 degrees so handle it appropriately.

My advise would be to forget the stainless damascus/san mai/rolling mills/gigantic swords stuff for now and concentrate on getting excellent single composition stainless blades to start off with. Fit, finish, and proper heat treatment is what makes a nice knife. Concentrate on those things first and you will be ahead of the game. Your first 2 knives look pretty good for just starting out, keep going and post your progress.

 

[CDHumiston]

LOL. Just dive right into the murky waters, from the high board, at 90 MPH with your hair on fire!

-The oven looks fine for heat treating stainless blades as long as it works and the temps are accurate.
-I would stick to a blade length that you can center in the oven (10"). Don't forget you will need a foil envelope on them as well, which adds to the length.
-I doubt you will be forge welding stainless in it as I think you will need to get the steel much hotter than 2000F to do it (2400-2500F area??). (although I've never researched/attempted to forge weld stainless and I'm just taking an educated guess).
-Although not absolutely necessary, LN2 when used properly as an extension of the quench, helps to eliminate retained austenite in stainless blade steels and usually results in a few extra initial points of hardness on the RC scale.
-To deal with LN2 properly, you need a dewar (not cheap, especially the ones with a large mouth that are desirable for a bladesmith).
-Ln2 can be obtained from most major welding gas suppliers. I'm sure there are other sources but that is where I get mine.
-To avoid freezing your face off, don't stick your face in the dewar I would recommend safety glasses, a face shield, and a pair of welding gloves, as well as common sense when handling it. LN2 is roughly -320 degrees so handle it appropriately.

My advise would be to forget the stainless damascus/san mai/rolling mills/gigantic swords stuff for now and concentrate on getting excellent single composition stainless blades to start off with. Fit, finish, and proper heat treatment is what makes a nice knife. Concentrate on those things first and you will be ahead of the game. Your first 2 knives look pretty good for just starting out, keep going and post your progress.

Very well thought out reply and wise advice.

As for the kiln, I think it will be a good starter for heat treating blades under 10"

When you heat treat a blade throw a coupon of the same steel in so you have something you can break and look at grain structure.

 

[Smurf masher]

LOL. Just dive right into the murky waters, from the high board, at 90 MPH with your hair on fire!

-The oven looks fine for heat treating stainless blades as long as it works and the temps are accurate.
-I would stick to a blade length that you can center in the oven (10"). Don't forget you will need a foil envelope on them as well, which adds to the length.
-I doubt you will be forge welding stainless in it as I think you will need to get the steel much hotter than 2000F to do it (2400-2500F area??). (although I've never researched/attempted to forge weld stainless and I'm just taking an educated guess).
-Although not absolutely necessary, LN2 when used properly as an extension of the quench, helps to eliminate retained austenite in stainless blade steels and usually results in a few extra initial points of hardness on the RC scale.
-To deal with LN2 properly, you need a dewar (not cheap, especially the ones with a large mouth that are desirable for a bladesmith).
-Ln2 can be obtained from most major welding gas suppliers. I'm sure there are other sources but that is where I get mine.
-To avoid freezing your face off, don't stick your face in the dewar I would recommend safety glasses, a face shield, and a pair of welding gloves, as well as common sense when handling it. LN2 is roughly -320 degrees so handle it appropriately.

My advise would be to forget the stainless damascus/san mai/rolling mills/gigantic swords stuff for now and concentrate on getting excellent single composition stainless blades to start off with. Fit, finish, and proper heat treatment is what makes a nice knife. Concentrate on those things first and you will be ahead of the game. Your first 2 knives look pretty good for just starting out, keep going and post your progress.

Thank you! And yes... I do tend to take the big dives. I like the challenge. But for sure I will be practicing with standard carbon blades, fittings and handle perfection, for a good few months. Your detailed advice is highly appreciated, thank you for taking the time to give such a detailed and expert reply. I'll definitaly be using stainless foil, argon in the packet, and tig welding the billet so it is air tight after careful clean grinding the contact points. (may also dip the welded billet in kerosine before putting in the foil) and yes, keeping the knives small. If I can make some decent locking knives, I think that would test my skills a lot.

Holding back on the rolling mill I disagree with. I was a mechanic for 2 years working under my dad, I'm highly practical, (built a house) did an engineering degree, and I'll be following these plans. https://www.anvilfire.com/AnvilCAM-II/index.php?video=McDonald_mill I know I can do it, and I have the time. I'll be aiming for somthing like what this guy made:

(amazing simple machine)

However I'll be simplifying the motor section by using a pre geared low speed motor from a winch, with some belts on larger gears to adjust to the final required speed. I'll also be modifying it a bit to add a counter weight so it has a bit of a reverse rolling fly press aspect to it as well, removing the lever that adjust the gap to simplify it, and instead using just the vice dial. I think the rolling mill will be pretty vital for decent damascus and for quieter production in a large suburban garden. (with countryside at the back) as for a power hammer, I've bought a 5 ton newton fly press from these guys https://www.usedflypress.com

Thank you again. any feedback and correction of anything I wrote above is appreciated and most likely needed.

 

[Smurf masher]

Very well thought out reply and wise advice.

As for the kiln, I think it will be a good starter for heat treating blades under 10"

When you heat treat a blade throw a coupon of the same steel in so you have something you can break and look at grain structure.

Noted and thanks! Wish me luck.

 

[Smurf masher]

Also. I've investigated (I googled a lot) that I can use dry ice to get a temp below 80 degrees c. From bohlers heat treatment formula, this is just about the perfect temp for m390 micro clean cryo treatment. (I bought 600mm by 1000mm sheet direct from bohler) Do you guys think this will work ok rather than using liquid nitrogen?

I think I want to try to perfect each skill separately, and work on some test knives from the m390, doing pure grinds and cuts to get the tang and blade length, with some blade shaping on the forge. No stainless damascus, no san mai just just yet. just mono stainless steel, and checking the rockwell hardness results to figure out the best steps. Once I have that cracked, and improved my other skills on the carbon steels, I might have a bash at some san mai.