- Joined
- Nov 4, 2015
- Messages
- 30
Forgive the long post, I'm trying to get as much of the story and as many of the details as I can right up front.
I'm a hobbyist and just starting out with bladesmithing. I've made a few stock removal knives from files, a few crude punches / wood chisels and a pair of rebar tongs from forging, and am now getting into making blades from scratch. For the time being, I'll be doing stock removal primarily. I've read through the stickies as well as countless other threads on several forms to collect as much info as I can process. Now I just need more hands-on practice.
I have a small 50 cal ammo can propane forge with a venturi burner that does well at getting things hot, but doesn't have much for temperature control. I'm using a 50 cal ammo can with about 1.5-2 gallons of canola oil for quenching, always heated to around 130F (+/- 10F, tested with a meat thermometer). Finally, I just picked up a small used kiln (Thermolyne 1300), and have a larger one on the way. I'm using 3/16 1084 bar stock purchased from two different reputable sellers on a major auction site.
My first several trial runs were using the forge exclusively. I heated several pieces of 1084 well past magnetic (oops) and quenched them in the warm oil, moving them back and forth from point to tang while submerged. The oil flared up quite a bit during the quench. After about 10-15 seconds, I'd remove them from the oil and allow them to finish cooling in still air. I tempered two of the pieces at 450F for an hour, cooled, and then another hour at 450F. Three other smaller test pieces were left untempered. After removing the decarb, I noticed that a file easily bit into one knife, and bit decently into the second one. I recall quenching the second knife several shades lower than the first, but still non-magnetic. Would the higher temperature (1600-1700F guestimated by shade) before quench on the first knife cause the low hardness? I shelved the first knife, and will be completing the second (harder) one to see how it ends up performing.
Ok, so a few failures at temperature control; whatever, life goes on, right? Here's where I'm stuck: the small test pieces that I didn't temper are also very tough, not brittle like I was expecting. Like the first knife mentioned above, they were most likely quenched well above the ideal temp (guestimating medium orange) and into 130F canola oil. I was able to put each one into a vise and smack them with a hand sledge until they were bent at a 90+ degree angle. Though they were more difficult to bend than similarly sized mild steel, none of them showed any cracks or other signs of stress. It's almost like they were annealed instead of hardened, despite being oil quenched very hot. I left them to sit, untempered, on my work bench for a few days, and no cracks have formed.
A few days later, my kiln showed up. I cranked it up to 1100C (~2000F) with a piece of mild steel inside as a baseline test, primarily to make sure it would reach the max temperature without blowing a fuse or tripping a breaker. Unfortunately I don't have a pyrometer, but I can say that the piece was at least a very bright orange, perhaps slightly brighter than the 1600-1700F pieces I had previously heated in the forge, perhaps dull yellow at most. The piece did start to stick to the bottom of the kiln (major pucker moment), which I didn't experience with any other samples after lowering the kiln temp. I reset the kiln for 815C / ~1500F and allowed it to cool down to the target temp, and then put two new pieces of ~2" x 2" x 3/16" 1084 in for testing. They were allowed them to soak for about 10 minutes, just to be sure, and then taken out one at a time for quench. Stupidly, I didn't test them on a magnet, but noted that both were a dull to medium red color (cloudy evening). I noticed that the oil didn't flare up with either piece, unlike the higher temp trials with the forge. Once again, without tempering, I put them into the vise and smacked them with a sledge. Both of them were able to bend at 90 degree angles with no cracks, though they took a significant amount of force to do so. I also noticed that a file skated decently well on both pieces. I was under the impression that if they were hard enough to skate a file, they should break rather than bend to that degree.
So that's where I'm at. I'm sure my temperature control needs the most work, but I was hoping to be able to break some of the sample pieces to check out the grain. So far, I haven't been able to do that. Perhaps I've been ~100-200 degrees too high in the forge, and ~100-200 degrees too low in the kiln (faulty thermocouple?). Maybe I'm taking too long getting them into the oil, or not moving them around enough during the quench. Maybe I'm taking them out of the oil too quickly. Maybe I bought questionable steel. Either way, I figured I'd have some luck by now - or perhaps I have, and I'm just expecting the untempered samples to shatter too easily.
Any suggestions?
I'm a hobbyist and just starting out with bladesmithing. I've made a few stock removal knives from files, a few crude punches / wood chisels and a pair of rebar tongs from forging, and am now getting into making blades from scratch. For the time being, I'll be doing stock removal primarily. I've read through the stickies as well as countless other threads on several forms to collect as much info as I can process. Now I just need more hands-on practice.
I have a small 50 cal ammo can propane forge with a venturi burner that does well at getting things hot, but doesn't have much for temperature control. I'm using a 50 cal ammo can with about 1.5-2 gallons of canola oil for quenching, always heated to around 130F (+/- 10F, tested with a meat thermometer). Finally, I just picked up a small used kiln (Thermolyne 1300), and have a larger one on the way. I'm using 3/16 1084 bar stock purchased from two different reputable sellers on a major auction site.
My first several trial runs were using the forge exclusively. I heated several pieces of 1084 well past magnetic (oops) and quenched them in the warm oil, moving them back and forth from point to tang while submerged. The oil flared up quite a bit during the quench. After about 10-15 seconds, I'd remove them from the oil and allow them to finish cooling in still air. I tempered two of the pieces at 450F for an hour, cooled, and then another hour at 450F. Three other smaller test pieces were left untempered. After removing the decarb, I noticed that a file easily bit into one knife, and bit decently into the second one. I recall quenching the second knife several shades lower than the first, but still non-magnetic. Would the higher temperature (1600-1700F guestimated by shade) before quench on the first knife cause the low hardness? I shelved the first knife, and will be completing the second (harder) one to see how it ends up performing.
Ok, so a few failures at temperature control; whatever, life goes on, right? Here's where I'm stuck: the small test pieces that I didn't temper are also very tough, not brittle like I was expecting. Like the first knife mentioned above, they were most likely quenched well above the ideal temp (guestimating medium orange) and into 130F canola oil. I was able to put each one into a vise and smack them with a hand sledge until they were bent at a 90+ degree angle. Though they were more difficult to bend than similarly sized mild steel, none of them showed any cracks or other signs of stress. It's almost like they were annealed instead of hardened, despite being oil quenched very hot. I left them to sit, untempered, on my work bench for a few days, and no cracks have formed.
A few days later, my kiln showed up. I cranked it up to 1100C (~2000F) with a piece of mild steel inside as a baseline test, primarily to make sure it would reach the max temperature without blowing a fuse or tripping a breaker. Unfortunately I don't have a pyrometer, but I can say that the piece was at least a very bright orange, perhaps slightly brighter than the 1600-1700F pieces I had previously heated in the forge, perhaps dull yellow at most. The piece did start to stick to the bottom of the kiln (major pucker moment), which I didn't experience with any other samples after lowering the kiln temp. I reset the kiln for 815C / ~1500F and allowed it to cool down to the target temp, and then put two new pieces of ~2" x 2" x 3/16" 1084 in for testing. They were allowed them to soak for about 10 minutes, just to be sure, and then taken out one at a time for quench. Stupidly, I didn't test them on a magnet, but noted that both were a dull to medium red color (cloudy evening). I noticed that the oil didn't flare up with either piece, unlike the higher temp trials with the forge. Once again, without tempering, I put them into the vise and smacked them with a sledge. Both of them were able to bend at 90 degree angles with no cracks, though they took a significant amount of force to do so. I also noticed that a file skated decently well on both pieces. I was under the impression that if they were hard enough to skate a file, they should break rather than bend to that degree.
So that's where I'm at. I'm sure my temperature control needs the most work, but I was hoping to be able to break some of the sample pieces to check out the grain. So far, I haven't been able to do that. Perhaps I've been ~100-200 degrees too high in the forge, and ~100-200 degrees too low in the kiln (faulty thermocouple?). Maybe I'm taking too long getting them into the oil, or not moving them around enough during the quench. Maybe I'm taking them out of the oil too quickly. Maybe I bought questionable steel. Either way, I figured I'd have some luck by now - or perhaps I have, and I'm just expecting the untempered samples to shatter too easily.
Any suggestions?
Last edited:
