So I just read through Mythtaken's primer on heat treating. Very informative, but I had a couple questions on the practical side of the whole process. As a beginner, what's everyone's opinion on the best way to go? I'm just about to order myself some 1084 or 1095 to get started out. Would the small brick forge forge I've seen instructions for in the forums here work? I've also got an old BBQ kicking around somewhere that would probably do well for that purpose if that would be better. Or what about the route of making up a few blades and then sending them away or maybe seeing if there's a place close by to get them professionally done? Thanks! winchester
Sorry, I should specify: I'm looking for options to both harden and temper. Doesn't need to be with the same apparatus/device either.
Some good questions. The simple answer to them is "it depends". Really, it comes down to space, ability, and interest. There are plenty of really good knifemakers who always send their blades out for heat treating. A lot of us hobbyists enjoy the learning process as much as the making, and heat treating is just another educational hill to climb. As a beginning maker, you may not want to add to the learning curve all at once. There's good reason to learn one part at a time; focus on designing and making your knives and leave the heat treat to someone else until you decide to tackle it. If you decide to do it yourself and have the space in your shop area, carbon steels like 1084 and 1095 are pretty easy to heat-treat. That leaves you the choice of gas, coal, or electric. A small two-brick forge will do the job (for larger blades you might consider Mapp gas instead of LP and perhaps a slightly larger burner to speed up the process). If you go with coal, an old Hibachi barbecue forge or a simple brake drum forge are easy to build (You can use a regular old barbecue too, but you don't need anything that big). You do need to do it outside or have a chimney for the fumes, if you go with coal. Or you can ask Mr. Visa to get you a new Paragon or EvenHeat electric kiln. Tempering carbon steel can be done in a cheap toaster oven (or the one in the kitchen, if you sand the blades first and your spouse is out of town....:moony I'm not sure if that answers your questions or adds to the confusion. Oh, and if it helps with the decision, Rob at Knifemaker.ca in Alberta offers a heat treating service.
Thanks so much Myth! Very informative once again, it helps a lot. I think I'd go with gas in the small brick forge if I decided to do it myself, and then possible the toaster oven method outside. You figure if I sand the blades before I put them in the oven, I can do them inside? If I did manage to catch a weekend where the lady of the house had vacated the premises for a little while, they wouldn't stink up the place irreparably so she'd notice when she came back? I'm already allowed to work with my files, etc. in the kitchen and I'd like not to have those privileges revoked, seeing as it would end up with me working outside in all likelihood (basement and garage space are a tad limited at the moment, but I'm working on that too). I'd love a Paragon or Evenheat, but I'd feel a tad unworthy given my skill level. I'll try it the barebones way first and see if I can get any good at it and then maybe start saving my pennies to upgrade if I do. Sending to Bob at knifemaker.ca is tempting but I'll have to think about it.
Yes, you can safely do the tempering in your kitchen oven, as the temperature you need is only 400-450F. I suggest sanding the blades first because when you harden them they'll get a black coating. Some of it is just the carbon coming out of the steel, but a lot of it is from your quenching oil. If you use something like canola oil, it's not so bad. When you temper, there'll be a little smoke and your house will smell like you're cooking something almost edible. If you choose another quenchant, such as used motor oil or transmission fluid.... You don't want that smoke and smell coming out of your kitchen stove. I have a cheap toaster oven set up in my shop (i.e., corner of the garage). It works just fine. The two-brick forge is dead easy to make. If you decide to go with that and need any additional information, just ask.
I believe I will go with the 2-brick method Myth followed by the out-of-the-house toaster oven temper, thanks. I looked up your tutorial on the small brick forge and it looks perfect for me. I did have a couple questions, though. I don't have anything like screen-door mesh lying around like you did, could you suggest an alternative? Maybe just some wire or something to hold the bricks together? And I think I know what you mean by refractory cement but I'm not sure, is there another name for it? And last, any recommendations on a torch? Also, kinda off-topic I know, but I haven't for the life of me been able to find someone who could answer this: I have a 4.5" angle grinder and a hacksaw and am going to get some 1084 or 1095 for my first project. Will either of those be sufficient for cutting 10xx? If I graduate to 440c eventually, will they work for that as well?
Hey man, I strongly STRONGLY do not recommend getting 1095 if you are planning on doing the heat treat yourself. At least not until your very comfortable with heat treatment. Don't get me wrong 1095 is good stuff but 1084 is better for home heat treatments and will still make an outstanding blade. You can use the tools you have to cut out the blades and you can even use that angle grinder to rough out the bevels if you have a good hand. Then finish them up with files and sandpaper. You can also use them on 440c all the "normal" knife steel you get is very soft and cuts fairly easy.
You can use wire or metal strapping to hold the bricks together. I just happened to have some screen that worked fine for mine. You also don't have to coat it with refractory. Again, that was just something I did because I had it around. It will work just fine with nothing but the two bricks and some wire (NOT galvanized) to hold them together. If I make another, I would coat the inside with a little ITC-100 to help raise the heat a bit, but it isn't necessary. As for the torch, you can start simple with the basic torch head that comes with the small gas cylinders, or use one on a hose like this. You can get an adapter that lets you attach the hose to a regular barbecue type LP tank. Of course, you can also build your own burner to give you just the heat you want.
