Low pressure natural gas burner success
by
Ronald E. Thompson
12/22/2010


Not too long ago this was bandied around quite a bit on Castinghobby (yahoo group). Now I have something good to report!





I was able to use the natural gas piped to my gas grill through a quick disconnect to fuel my furnace.


I bought a replacement 10' hose kit with the quick disconnect and plumbed it to a ball valve at the burner. The burner is nothing more than a short length of steel tubing that started life as a swing set.

One end was oval shaped and almost fit the hair dryer I was using. One tap with a hammer and it slipped right in.
I drilled a 7/16” hole near the blower end and threaded it for the "-pipe thread of the ball valve. A pipe thread to 3/8” flare adapter mated this to the stock flare on the hose. Sweet!





Since the tubing fit the hair dryer so well, a few wraps of blue masking tape was enough to make the seal.

The moment of truth. Could something this simple and easy to throw together actually work?

I turned the hair dryer on low, no heat. I turned on the gas and held the flame of a butane lighter to the business end of the tube. It burned as long as I held the flame to it, but it was obvious the fuel air mixture was moving too fast. Time for a flare.

Wait a minute! A lot of burners do fine in the furnace when they won’t do much in open air. I drug the furnace over and inserted the new burner.
How to light it? I tore off a small piece of paper towel, lit it and tossed it in the furnace. Woosh! It was burning!
Not very well, though. It was still getting too much air. But it stayed lit. I held my hand over the air inlet and could make it burn well if I covered half of it. Time for more blue masking tape!
I went and got my old I-phone to take these photos. My wife is out of town visiting relatives and my good camera went too.




This is the natural gas line and the quick disconect. The furnace is plugged in and the gas grill hose is laying loose.



This is the small ball valve.



And the other side...



A little closer...



Plenty hot. The light blue flame doesn't show up, but it's there.



You can see the pipe crucible starting to glow.

I think the ball valve is somewhat restrictive because it is only 1/4" where everything else is 3/8". If I need more heat, I'll try replacing it. But for now, no more lugging propane tanks or running out just before the pour!

The only bad thing is I am limited to just outside the back door of the house. I need about 75 feet of hose to get me back to the casting area.