Fredeen Blades

Hey there Graham,hope you had a good Christmas and a happy new year. I was wondering about the design of your heat treat furnace, is that a propane cylinder that you modified?

Hey Dan, a belated Happy new year to you as well. Enjoyed some rare "time off" over the holidays, and spent as much of it as I could in the shop which was great.

As for my HT furnace, you are correct, it is done out of an old 100 lb propane cylinder (Safety note, please DO NOT attempt to cut open an old propane cylider without knowing 100% what you are doing and how to do it safely. If you have any doubts or questions in your mind as to the necessary precautions, better to leave it sit and be alive and in one piece, than to make a mistake and have serious injuries or pushing up daisies).

Basically just cut open the cylinder, cut a hole in the bottom for the burner mounting bracket, welded that in, lined the furnace with ceramic blanket, tack welded the top back on (didn't want to fool with hinges, and tack welds are quick to cut if I need inside). Built the burner assembly , wired up the PID controller and it was good to go (done in a weekend).

Its digitally controlled, so the way it works is there is a gas solenoid valve connected to the gas line feeding into the burner. That solenoid valve is controlled by a PID controller, which recieves voltage (temperature) input from a thermocouple. The thermocouple tells the PID controller how hot it is inside the furnace, and you tell the PID controller how hot you want it to be inside the furnace. The controller takes the set value for the temperature and "compares" it against the thermocouple readings, if the temp in the furnace is too low, the PID controller provides voltage to the solenoid valve, which opens it up and fires the burner. When the temp inside reaches the set temp (or a hair before) the PID controller shuts the soleniod, turning off the burner.

It does a pretty decent job, I've actually been running it using relay settings rather than the actual PID controller (fried the PID jack in the back when I accidently crossed some wiring, that sucker is small and its a challenge to keep the nest of wires apart), and even with that I can keep a temp of about +/- 10 F. Keep in mind thats the temperature fluxuations of the thermocouple, which mine is only 1/16" thick, so its super sensitive to heat changes. I'm sure the blades may only change temp by a couple degrees.

I built it with the idea of doing swords in it, which I can. However I discovered that it needs a top burner to keep an even heat throughout the entire length (theres a slight temperature differential bottom to top). Seeing as I haven't messed with any swords for awhile, havent gotten around to upgrading it yet (also might replace the PID controller so I can actually run it on PID settings rather than the relay, which should give even better control over the temp). Also going to throw in some needle valves so I can adjust top to bottom temps... and have considered putting in a dual stage burner arrangement (basically 2 sets of parallel gas lines into the burner, one with needle valve, the other with the solenoid, that way you can keep the burner running really low and then the solenoid would open up more gas when needed, this makes the temp change a bit more gradual which cuts down on over/under shooting by the PID controller).

Also built this with the idea that some day I might convert it into a high temp salt pot. All it would need is a SS tube filled with the salt to be dropped in, and then just move the thermocouple.

Anyway, there's a quick primer on how it works. Happy to answer anymore questions.

hey thanks for getting back to me Graham and I'm glad you had good times over the hollidays.That sounds like one serious heat treat system.Since I'm just getting my feet wet in this I'm not sure what to use as far as heat treatment.Some have suggested to purchase a pottery kiln or to even use an old electric toaster oven that can obtain 500 degrees.I figured to start out doing stock removal before forging,getting used to grinding techniques and all.I know I'll have to harden and then heat treat afterwards but what about annealing as well?I"ll be sure to look through the tutorials page for tech info but i would love some insight on low budget things I can do to get going,sort of chomping on the bit!! Anywho have a great day and I look forward to hearing from you

For heat treatment you have a few different options, some more costly than others.

Pottery kilns are great for HT (so long as they'll reach about 1700 F). Can't go wrong with an electric setup that can give relatively tight temp controls. You can also buy electric heat treat ovens (paragons, surgar creek kilns, etc) which are super great. However, these are usually far from cheap and therefore out of budget for just about all besides serious makers (and even then sometimes).

An old toaster oven works well for tempering, however thats all it will do. It won't get anywhere near the temps you'd need to harden a blade (most critical or "austenizing" temps for blade steels lie between 1450 F-1650 F). You can also temper in the kitchen oven... so long as the wife/lady of the house is out of the house for a good few hours or you get her permission first . Thats why most use toaster ovens in fact .

So your other options are either build yourself some sort of forge/heat treat furnace, or send your blades out to be professionally heat treated until you get a setup of your own.

Personally, if you are wanting to get into forging some day, I'd say might as well get a forge going. If you don't have any other blacksmithing equipment (anvil, hammers, etc.) you can still use the forge for hardening blades until you can get the other equipment going.

A nice little gas forge can be built for somewhere on the order of $100-$150, give or take, depending on how resourceful you are in finding the parts.

You could also build a little coal/charcoal forge for next to nothing (maybe even free if you play your cards right). You can build a simple breakdrum forge, or washtub forge for literally a couple bucks at the scrap yard, or often times free with a little scrounging. You could also dig a "pit" forge in your back yard and use it (all you need is a pipe with some holes and something to provide air to it). This is not the best route to go for high performance heat treatment, but it will let you get blades hot enough to harden and anneal, and thats what you need.

And third option is to pay to have your blade heat treated by someone. There might be a spring shop near you that will do them, or you can send them off to a number of folks who will do them. This of course costs money per blade (not sure how much, never done it myself), and as soon as you do a few blades this way and eventually you will have spent what it would cost to get a little forge going. But this is an option if you are unable to build anything for yourself.

I can get forge building links for you, or you should be able to find a good number online (I know google spits out a ton of them). And as always am happy to answer your questions as they arise.

Hi

I'm new to all this and will be attempting my first pattern welded blade on the coal forge I have just finished building - Just want to say thanks for the vids you posted on youtube - cleared up a lot of questions I had and will save me a lot of valuable time.

Hello Tim and welcome to my website.

Glad my videos were of some help to you and I hope your first pattern welding project goes well. Feel free to ask any questions that may come up along the way and let me know how it goes.

I hope to some day get some more videos up (I have to finish off that tutorial, and would also like to make some other tutorials and videos). I just need some more time in the shop and more time in the day for things like that unfortunately.

Have a good one,

Graham

Thanks - more videos would definatly be good but I know what it's like with trying to find the time to do anything - A taxidernist has just commisioned a gemsbok horn bow and I'll get a whole lot of warthog tusk and girrafe bone in the deal, so gotta do it - need the cash anyhow.