Heat Treat on a 71 camaro leaf spring knife video

[Kevster]

Originally Posted by WBE

Non-magnetic is only step A 2 in austenitizing simple steels. You won't reach A 3, full austenitization, until you come to at least 1450?. Non-magnetic is 1414?, and not enough to get a good solution with well dispersed carbides. 1475? to 1500? is the more ideal heat range, and is roughly one shade of red beyond non-magnetic. Austentization begins at about 1333?, but does not complete until above at least the 1450? range. If you worry about grain growth, it won't be significant unless you go above 1500? for a length of time. Think of an A 1 solution as thick mud, A 2 as soupy sticky mud, and A 3 as brown slushy water. Not a perfect analogy, but close enough. Another point is that allowing the blade to cool to ambient slowly in air after a temper cycle does nothing to help it, and only allows you to burn unnecessary energy in your oven waiting for the blade to cool down. Quench in water and you can put it right back in for another cycle. This process also helps convert any retained austenite that may be present.

I agree, I also normalize the blade twice, I bring it to red hot and let it air cool to black, then I put the blade in a stainless tube in my forge, I get the forge up to temp. And put the blade in and hold the temp at 1500, when I think I'm there I'll pull the blade and check it with a magnet, if it's good I'll put it back in the forge at 1500 for a few minutes and the go straight into heated quench oil.

Thanks for the tip on tempering I'll try the water quench next time.

[racjarrett88]

I do one 2 hour cycle at 425 is this bad?

[racjarrett88]

When tempering use an oven thermometer or 2 next to blade never trust oven setting.

[WBE]

Originally Posted by racjarrett88

I do one 2 hour cycle at 425 is this bad?

2 1 hour tempers would be better. Some believe 3 is better yet, but after 2 tempers you reach a point of diminshed return in all areas. 3 does no harm, but really only helps the power companys, or fuel suppliers pockets. Quench in water after both. This is actually good for increasing martensite. Only maybe 1 or 2 percent, but you will be saving fuel and time also. 425? is usually a good compromise between hardness, strength, and toughness with most common carbon blade steels. If primarily a slicer, you might like 400? a tad better. Some might like a bit less, but the edge may be prone to chipping, and should be tested. You can re-temper higher if it is.

[Imakethings]

Originally Posted by Hurley

Yeah Ray and I have discussed extensively about how I need to get kaowool and satanite coating, he keeps telling me until he's blue in the keyboard............lol, I really need to order some very soon. I don't know of any refractories in South GA, so yes I prolly need some help. Or I could just order some firebricks from home depot. I really like this propane, now that I'm over the inital cost of a tank. I have a small MAPP torch, but ray was telling me there was a way to feed propane into the forge.

Good!
I'm lucky enough to have a couple pottery supply places near me that keep firebrick and kaowool in stock. They usually cut me a good deal since I wander in and buy em by the case.

Right, now I've discovered that pottery supply companies are more common than blacksmith supply companies. Googling 'pottery supply georgia' supplied me with two places in Atlanta that look like they will have what you will need, and many others.
First:
http://www.davensceramiccenter.com/Catalog.html
A quick dig through their catalog and I found that they carry soft and hard firebrick and inswool. No luck on ITC or Satanite though, they probably do have it, just not in their catalog.

Second:
http://www.atlanticpotterysupply.com...rt/pc/home.asp
Didn't find it on their site, but considering the selection they probably have it. Call and ask, they're just across the border in Florida.

The other one in Atlanta didn't look like they would have the right stuff, but I think these two are your best bets. If you get tired or frustrated with trying to do it yourself I'll be happy to build you a propane forge.

Marc

[Bowman]

A good effort Hurley, I commend you for that effort. You will learn quickly from this forum. My knife making is painfully slow and with a lot of sweat equity in each blade, I want to get it right. To do that I have studied much and asked questions. You obviously put some time into that knife so I wouldn't hit anymore with a hammer unless you are testing to destruction. As you might know already, start with known materials and build a simple forge. Part of what I have enjoyed in my very limited knife making has been making the tools to make a knife. These tools will also help in your success to produce a quality knife. Best of luck!

[Hurley]

Thank you Bowman, actually I am not sure what I was doing with it, not sure if I was going all out destruction or not. I suppose I was but I never too it to the point of totally destructing it. Oh well, live and learn!

[DanCom]

Hurley,

I made a super-simple firebrick forge from a swirl tip MAPP/Propane torch. It will certainly get carbon steel up to temperature. Add a second torch and you can get steel yellow hot.

Google "fire brick forge" and you'll see a dozen variations. Basically a few insulating fire bricks and a swirl-tip torch. Mine is a combination of several designs.

http://dcknives.blogspot.ca/p/blog-page.html


A good initial test of hardness is the "file skate." When a file is pressed across the blade it makes a very glassy sound as the file fails to bite. That's a satisfying sound!

However fun the fire brick forge is, ultimately it is difficult to control and maintain desired temperatures. With my appetite for stainless varieties, the electric forge with a PID temperature controller is the way to go.

Dan

[Hurley]

I'm going to build one of those "simple forges" I already have a 2' x 4' piece of kaowool coming. gonna get some 8" stovepipe, some satanite to coat it and maybe a firebrick gor a bottom. But hey, I am always looking at things to help improve on the idea, so I'll go check out your link.......thanks for taking the time to post it for me! It's much appreciated, one can never learn too much about this!