Fredeen Blades

You have a great tutorial on pattern welded blades.  I was watching you draw out the billet in the video and trying to see your forge in the background.

I was wondering about your forge design.  Do you use multiple burners  without a blower or the simple blower design?  I set up my gas forge with a blower and the geometry to make the fire spin. It uniformly heats the forge and does not use much propane.  

ernie

My gas forge was made from an old 20 lb propane cylinder for the body. It uses two Reil styled atmospheric burners, set at an angle to spiral the flame. I built it a good few years ago before I really knew all that much, it has its short commings and isn't quiet as efficient as it could be, but it still works well, so I havent felt the need to get around to building another. Someday maybe.

Here is a picture of it

It has the hinged front door for easy access for relining and lighting the forge, etc. It has a pass through in the back for long work. I'll plug this up with some extra insulation when only working shorter blades to make it more efficient. It has a sacrificial fire brick floor for welding, the rest of the insulation is ceramic blanket that is coated with some satanite (on hard use areas) and a bit of ITC-100 on the rest of the upper interrior. It will reach welding temperatures without issue, proably at about 5 psi (usually run 10 psi to warm it up faster, then chop down to about 5 psi once up to heat). Forging temps at 3 psi. These are pretty good for atmosphereic burners. It will eat a bit more propane than a blown burner, but at that time I didn't feel like fooling around with blowers, and the atmospherics work well enough that I havent seen the need to switch over.

thanks, That looks like a great forge.  Mine was easy to build but difficult to light,  I am redesigning the nozzle to make it retain the flame.  Right now it burns like a pulse jet and is not stable until it gets quite hot.  I have been thinking about adding electric ignition like an oil burner uses.

ernie

Sounds like a burner flare issue. A lot of burner designs overlook burner flares. The burner flare is designed to create a bit of an expansion, slowing the speed of the exiting gasses. Otherwise the unburnt fuel exits at a speed greater than the rate of combustion, and your flame is essentially blown out.

How do you light your forge? Do you open just gas, air and gas? I don't know if electric ignition would be all that necessary unless you were going for something automated like a digitally controlled HT forge. But I guess it would be handy. You could probably just drill a hole in by where the gas jet is inside the burner body and thread in one of of those push button barbacue grill spark lighters, or rig up a spark plug.

If you need any help with burners or forges, don't hesitate, I've got some decent experience with building them (got a pic of my new digitally controlled vertical HT furnace on the home page) and some college course work in fluid mechanics.

I had a 3/4 pipe with a reduced opening which would make the gas flow faster and blow out the forge as you mentioned.   Now I changed to a 1 in pipe with a straight pipe that ends partway through the refractory.  This pipe now fills the hole entering the forge so outside air is not being pulled in and I have a built in refractory flare.  I think this will keep the end of the pipe from getting burnt off.  

The second change is that I put a 2" water pipe gate valve in the air supply so I have a fine control over the air to match the gate valve on the gas input.  

Lighting and controlling the flame is now easy.  I can turn down the air to a minimum, spray a paper towel with WD40 and roll it up.  I light it and put it in the forge with tongs.  When I turn on the gas, it lights right off and I have no problem getting a neutral flame that is stable.

thanks for the help

ernie

Glad you've got it running better. Always glad to help where I can