I would like to run a gas-fired forge using the house gas line (UK) - does
anyone know of any links/resources?
I assume that I will need a forced air burner rather than venturi (Reill
type) - is there anything else I need to take into account?
I will be getting the connection to the smithy run by a registered gas
fitter/plumber with 3/4" gas pipe (or equivalent -22mm?). Will I need an
"anti-flashback" valve type thing?
I am intending to make the burner myself, based on the Reill burner +
centrifugal fan - the "smithy" is three-wall + roof, sheet metal (old garage
doors) and 3"x9" beam "building" about 100 yards from the nearest other
structure, so I'm only worried about myself in the event of explosive self
Any advice/information would be appreciated.
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
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)
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
That's choice number 2.
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.
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"
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
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",
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.
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
6) adjust mixture after autoingnite point is reached, go to work.
Air first, then fuel! Don't get it backwards.
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)
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