Forge burner running town gas?

Cool question and here's mine to go with it... Is that methane? I heard the methane pressure in the US is 4 pounds(?) among other numbers. :/ Is there enough flow in the US from a house sized setup?

Another cool question/can of worms. ;)

That "Whomp-sound" is all methane and air does... in the "powerful expolsion" department. :)

Singe the hair off your arms is all unless you've got your face in there while lighting the dangged thing, then you might singe the heck out of your eye brows too. Every guy needs to do that at least once I guess. ;)

Acetylene and oxygen has more "oomph" to it, but still, for the most part, all that stuff will do is damage your hearing. :)

Alvin in AZ (using propane for heat treating knife blades)

It's "natural gas" - all I know is it is drilled like oil

There's a hole where a house used to be in my mother's street from a natural gas explosion.

-- BigEgg

You can't do this legally, under UK mains gas plumbing laws.

Go for propane.

Somehow, I knew someone would say that :.))

Is that because a homebuilt burner wouldn't be legal, or the entire system? Is it possible to buy a burner, or have one manufactured/inspected by a CORGI plumber?

That's choice number 2.

-- BigEgg

I run natural gas and forced air, works great. Mine is an old Johnson four-burner. It has an 8" impeller driven by a 1.5 hp motor, and a 'no power cutoff valve' interlock on the gas feed, downstream of the flow valve. The gas feed is just a 1/2" pipe that dumps into the blower inlet, with a little round plate threaded on to 'choke' the air inlet on the blower housing. The blower dumps into a cast manifold that looks a lot like an old Jeep exhaust manifold and up to the side of the box where it dumps into four cast-in nozzles that penetrate the side of the box. It has a swing-away lid mounted to one end of the box. The newer models have sensors that detect flameout in the box, some sort of UV light sensor IIRC.

Natural gas and forced air is a lot like an early jet engine; it's cranky when it's cold, don't turn your back on it until the back wall gets up to autoignite temp. Mine has flamed out, compressor stalled, backfired, hung started, and yes, I've lost an eyebrow or three over the years. But it's CLEAN, the fire is completely adjustable in both temp and atmosphere, it stays where you put it, you don't have the EPA breathing down your neck, or complaints from the neighbors about the small mountain of black rock in the yard. Choke the air down and you can suck a lot of gas through the line. I can get 3000 degrees on a cold dry winter day.

I recently rebuilt mine, using the hard firebricks and castable refractory. After the curing in was complete, it worked like new. I expect ot get another decade out of this lining.

Charly

Natural gas is mostly methane and provides about 60,000 BTU's per pound whereas Propane provides about 90,000 BTU's per pound. Point is they both have a lot of energy, well beyond a Whomp if treated poorly. We ran almost all of our heat treating furnaces on natural gas in a large plant. I think "Charly the Bastard" just had a comments about his own natural gas forge for making damascus knife blanks.

I notice that one poster said that you can't do it in the UK and another said that you should use propane. I'd also vote for the propane, just because it makes your setup portable and no worries about "mains" connections, etc.

Pete Stanaitis

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snipped-for-privacy@XX.com wrote:

I forget the details. But it's even beyond the remit of CORGIs and into industrial burner design and supply. There's a _lot_ of paperwork. If you buy a kiln (I've only encountered this in relation to glass working), then you can have it installed by a CORGI. But they're not sufficient to certify a design from scratch as appropriate and safe.

There are also technical problems that natural gas isn't such a good choice of gas as propane. There are plenty of gas / blown air hearths and chip forges around S/H (often ex-schools) because people who've used them found they never got hot enough.

If I had _space_, then I'd go straight for coke. It's easy. I'm using Jarkman's Reil propane in a firebrick box at present, and even that's never really hot enough - especially for Ti.

Yeah yeah yeah, my gramdma's sister died that way, the floor was all that was left standing. :/ A large fire cracker could do that too. Compare the volume of the two.

...just how big is that forge you're making anyway? ;)

The whomp you're going to get lighting it up (if you don't do it right) is the worst you're going to get. If you loosly fashion your forge from sticks and cardboard you might be able to get it to fly to pieces, but the pieces won't hurt you unless they hit you in the eye. I'm talking about getting hurt as opposed to "just spooked", ok? :)

Alvin in AZ

I realised the above, but I need to know details - diameter of feed pipe, air input from fan. "Will it work at all?" , antiflash back valves or whatever - I have no qualms about an "illegal" gas fixture if it does the job.

-- BigEgg

I guess I should have included the starting drill, my bad.

1) clean out the box and visually inspect nozzels for obstruction. 2) prepare kindling, usually a sheet of newsprint wadded up. 3) light kindling, place in box, close lid. 4)power on, impeller to speed. 5) open flow valve until ignition is achieved, adjust to slightly rich mixture to warm box. 6) adjust mixture after autoingnite point is reached, go to work.

Air first, then fuel! Don't get it backwards.

Charly

In the UK any gas appliance has to pass a certification 'type approval' test, and although in theory you could design your own burner and submit it for approval, you'll need deep pockets. The rules for piped gas and propane cylinders are quite different, the later not yet being quite so draconian.

You'll probably find that you can buy a lot of the big 37Kg propane cylinders for what Mr CORGI plumber will charge to pipe your forge. Although I have natural gas in my (home) foundry I use propane for the furnace, as being a long pipe run from the house there would be too great a pressure drop when the furnace is burning (you are only allowed a 1 millibar drop along the pipe)

AWEM

Ever figure up the cost difference between NG and propane? (figuring-in that propane is hotter that is:) (I knowz-it, with NG you don't have to go get it or have it delivered by truck;)

Almost added that to the original but fiNgered I had been windy enough already. ;)

Blacksmithing demo in Marana AZ on Saturn-day, me and my son (the tig welder) is going. :)

Alvin in AZ