Thread: Gas forge for heat treating?

Originally Posted by jfk742

Man I sure hope I can make it. It would be nice to be a little more social than I was. I couldn’t have asked for more. Great company and awesome instruction.

That was worth saying twice and then having it repeated.

For a burner lookup ron reil and read his info.
The basics are a pipe with and end cap.
Drill a wire gauge 60 hole into the end cap. 3/4" pipe will be fine. This will be your burner.
You will take another piece of pipe large enough to slide over the 3/4" burner. In one end you will drill out numerous holes about 3/8" diameter. These will be your venturi where the air will be sucked in and mixed with the gas.
You will also need a short piece of pipe to fit over the venturi pipe. This will function as a "choke" to control the amount of air being mixed with the propane. It will help in setting a neutral
flame.
This just a rough outline.

The heat treating forge was copied from one that Howard Clark built at one of his workshops on metalurgy.
His was a 30 gallon water tank.
Yes, the idea is to have enough volume in the tank to make it slower heating.
The other requirement is to have a burner with a small enough orfice to allow only a small amount of gas to enter. A wire gauge 60 was almost to large.

Ignorant question time....I can see I should have paid more attention. I was pretty much staying out of the way.
I had assumed the kiln was being used for heat treating, but perhaps only tempering at Charlie's?
If a toaster oven is adequate for tempering, seems a kiln is a bit overkill for that?
Is the pipe inside of Vic's forge a 'muffler'?

Would it be possible to make a forge that could be used for forging and heat treating as well?

Tom, I would think one would be better served with two different sized forges, one for forging the other for ht. That’s why Victor changes his set up with the bricks. Smaller is easier to heat up for forging or welding while the larger volume for heat treat is easier to keep temps low and more consistent.

People were using the kiln for heat treating as well. It takes longer to get to temp and costs around $1500. For simple carbon steels you don’t need any crazy heating profiles, generally, as I understand it, get it to critical and quench. The cross sections of knives and razors don’t require extended soak times.

Tempering can be done in anything that will hold temp relatively flat, wife’s oven, toaster, etc... The flatter you can hold temps though the easier it would be to get repeatable results. I really liked Charlie’s salt bath for tempering, both his ht forge and salt bath held really flat temps not to mention I can find the parts for either cheaply or for free.

Originally Posted by sharptonn

Is the pipe inside of Vic's forge a 'muffler'?

Yes. Muffler, muffle, muffel, or whatever. It helps get even heat and a small piece of charcoal in the pipe makes a CO atmosphere which prevents scaling and decarburization, Though the decarburization is not much of a problem over such short soak times.

Lots to learn!

A forge and a muffle are a great way to heat treat. Victors pile of bricks and muffle is one of the most versatile and adaptable ways to make a forge. A more standard forge will also work. A propane forge with a muffle is a great option, there are lots of ways to get the job the done, it is technique that matters not so much which tool you use.

I mostly made my heat treat for the meet and because I like to tinker.

Here is how I build my burners, https://youtu.be/9u5URUHZhGs When I am sticking the burner in a forge I omit the flare. when I am using outside the forge I add the flare.

An ebay meter and a thermocouple will work for the temp it does not have to be installed like mine. The more important thing is to learn to see the transformation of the steel as it becomes critical. https://www.google.com/url?sa=t&rct=...FiDd60Sz_eXtRl

So, is the muffle a sort of container inside the forge (like a piece of pipe) that the blade is place into to eliminate hot spots?

Chunk of pipe, to even out heat