Ray Rogers Handcrafted Knives

How to Build Your Own Forced Air System from Scrap!

Now it's time to put our home made blower together with our home made gate valve and a couple of pieces of pipe to make a functioning forced air burner. The picture above is my finished burner. The blower and gate valve are connected by a piece of 2" PVC pipe. The fuel/air mixing chamber is also PVC but, of course, the burner tube itseld is a section of 1" black iron pipe. Everything is held together with duct tape, the handy man's friend.

This unit is fully functional and will get about as hot as any single burner you can build. That said, the purpose here is to illustrate just how little it actually takes to build one of these things. Obviously, I do not recommend using PVC pipe if you can get steel pipe and duct tape isn't as good as welding or even a good epoxy. Use the best materials and methods at your disposal. The most important things are to not have any gas leaks and to keep plastic parts and electrical wires as far away from hot things as possible. The forced air itself acts as an air conditioner for the burner tube so the PVC pipe never even gets warm but that doesn't help much if you drop a red hot billet on a plastic part!

My regulator is the one from my Big Kahuna BBQ burner. It's a 10 psi regulator with a needle valve that can be used for gas flow adjustment. A fancier regulator would be better but this is all you need. Note the fire extinguisher and make sure you have several. Honestly, I have so many fire extinguishers around here I've lost count!

The gate valve attached to the blower and the fuel/air chamber. The gas line from the regulator is inserted into the fuel/air chamber just above the gate valve.

One end of the burner tube is threaded into the forced air chamber and the other enters into the forge body. The burner tube is just a straight piece of 1" black iron pipe in any convenient length. There are no flares or orifices or any other complex crap - it's just a tube, period.

That's it, that's all there is. As you can see, it really, really works!


A forge is not a toy and messing around with large quantites of flammable gas can be very dangerous! It is YOUR responsibility to exercise due caution and care if you chose to build a forge. Be sure to comply with all local regulations and restrictions. This web page is not intended as a guide for you to use when building a forge. It is merely intended as a record of what I did and as a way of illustrating the basic fundamentals of how a forge works. I am not responsible for what you choose to do with this information.

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Ray Rogers Handcrafted Knives