Forge Options?

[woodwose]

For some time now I've been going back and forth between building or buying a venturi style forge burner. They seem dead simple to make, I know a couple local people who have made them, but they seem to take a bit more trial and error and tuning than I want to bother with right now, so I'd rather just buy one. I've been thinking about a T-Rex burner from Hybrid Burners (http://www.hybridburners.com). Are these guys reputable? Good or bad experiences with them? Is there a better option in that price range? etc...?

[Zanetto]

Hi Woodwose,

I bought a 1" T-Rex burner several years ago when I was building my raising forge. I cannot say enough positive things about it. It is very well made and performs wonderfully right out of the box. Nice adjustable choke design and it gets HOT! You won't go wrong with this burner.

Cheers,
Rob

[Thaddeus]

We used a t-rex burner in a tempering furnace when I was up at NESMhttp://www.newenglandschoolofmetalwork.com/index.php.
It was very adjustable which is awesome. They had it set up with a thermocouple and could dial in the temperature very accurately.

The Burner can be mounted in a smaller chamber and get very hot as Zanetto said.

Get one and you wont go wrong.

It's my next forge related purchase I think.
Sure you could mess around building one and getting the specs right and tuning it for less money, but I would rather spend that time and energy with a hammer in my hand.

If you want to shop around you can also check out:
http://www.zoellerforge.com/zburner.html
and
http://www.chileforge.com/NewDiablomainPage.html
The chili burners are pretty looking. I dont have any comparative performance information at this point and have only seen the t-rex in operation, I was very impressed with that.

[Vermillion]

Thaddeus,

Do you know if they were using a "pulse" method, in other words the temperature controller would turn the burner on and off, or if it actually adjusted fuel flow?

I was looking into this for my little knife forge, and I could find solenoids that would turn the fuel flow on/off, but then you get into ignition/reignition issues I didn't want to deal with on a very small forge.

Solenoids that adjusted fuel flow were available, but extremely expensive. Maybe I was looking in the wrong place. Thanks!

[Thaddeus]

It was constant flow. They had a needle valve in line with the burner and could regulate the pressure from the main line that way. Then adjusting the choke on the burner gave further fine tuning. It was very precise and would set and hold an exact temperature. I resisted the temptation to experiment with it, since it was a class and there was a crew of people who were using it for heat treating. But it didnt look terribly difficult to figure out.
The thing that we struggled with most was the size of the aperture on the oven door. When opened it would drop the temperature pretty dramatically, but this was a 'first go' that Derek the director had built some long time ago in the distant past so there was as he pointed out a lot of room for improvement on the design. (It was made from a large 2' diameter metal drum of some sort and had a hinged stove type door that opened completely to one side.)

For forging I would worry less about temperature control and more about efficient burner and chamber design. A low pressure atmospheric burner as discussed above would be great especially if coupled with a venturi style fire box. A cylindrical fire chamber with the burner inlet offset from center so that the burning gas swirls rather than blasts straight into the floor or the wall.
I have a forgemaster two burner forge.
It is not efficient.
It has two basic settings: immolate and off.
I can crank the regulator down to about 2-3 psi and get a slightly cooler fire, but any errant wind through the door knocks one or the other of the burners out and the thing starts to stutter like a buzz bomb. It also inlets the gas directly down from the top into a large rectangular chamber. It is a fine design for farriers (the actual intended market) but pretty lousy for knife making, and sort of useless for armour.
I am planning on building a much smaller chambered forge using a high temp refractory tube a friend showed me some pictures of. Unfortunately all I have is a phone number and some now sort of indecipherable notes but I recall him saying that it wasnt very expensive to build and heats very quickly, although his is blown rather than atmospheric.

Anyway back to the forge. There is a seax out there taking shape.

[AwP]

Much simplier to make yourself would be a burner with a blower attached. You'd have a bigger pipe attached to an air source, drill a small hole in it and insert a small tube that connects to your gas. It will burn hotter with less gas, be more easily adjustable, and there's nothing tricky about putting it together.

[PatternWeld]

Before you buy, design, build or decide, go here.

http://ronreil.abana.org/design1.shtml

[woodwose]

Before you buy, design, build or decide, go here.

http://ronreil.abana.org/design1.shtml

Done, read, and bookmarked

Much simplier to make yourself would be a burner with a blower attached...

I've considered it, I used one in the sculpture studio in college and in the shop I used to do most of my metalwork out of. In the later shop I also used several home built venturi style burners and they seem a lot more versatile, which is something I want for the first forge in my own shop... gas forges I've seen with electric blowers seem like rather cumbersome things with the burner pretty much built into it; I like the idea of the burner being pretty much a beefed up hand torch that is easy to plug into a brick pile, cylindrical or other sort of chamber.

A cylindrical fire chamber with the burner inlet offset from center...

That sounds pretty much like what a blacksmith I went to school with gave me. He was a grad student who hung around the sculpture studio a lot, was sort of the professors pet blacksmith, and I was like his pet smith; then at the end of the semester he gave me a rusty old forge chamber. It's probably eight or so inch inside diameter, maybe 1/4" thick walls, hope that is big enough once its all insulated... gotta go back and read up on forge designs some more. I might have to track him down later and let him know I'm getting some use out of it.

I bought a 1" T-Rex burner several years ago when I was building my raising forge. I cannot say enough positive things about it. It is very well made and performs wonderfully right out of the box. Nice adjustable choke design and it gets HOT! You won't go wrong with this burner.

well, based on what I've read here and elsewhere I decided to go ahead and order the T-Rex. I'm really looking forward to this, been wanting to set up a forge for years. Over the last few months to help motivate me to stop thinking about it and actually do it I have been working on projects that I can start but not finish without a forge... got a nice pile of trammel hooks in progress, and a couple repoused face plates that need annealing before I can make more progress.

[Darius von Tannenberg]

With all the talk of burners did anyone tell you about backfires? There is a
kind of one way valve you "WILL NEED" for your forge. It keeps your gas meter
in your yard and not in orbit. Even if you use propane you still need the "flashback"
arrestor. Bombs are not cool in the garage. It's another reason I burn charcoal.

[PatternWeld]

Darius,

While I agree an arrestor is a good safety idea. You should be aware that most Venturi burners don't have the negative atmosphere / forge bomb issue.

I address this with a ball valve on the burner distribution bar.

Tank on... check redhead pressure... crack ball valve... Push the ignitor a couple times... forge lights up. OR I stick a lil bit of oily rag/paper towel into the forge, lit before I crack the ball valve.

Off? Turn redhead down to 4-5 lbs. close ball valve... turn off tank... release line pressure into hot forge.

Its only with the forced air or oil injected types where you get the "forge bomb" conditions.

[Thomas Powers]

Acetylene will exothermically disassociate even with no oxygen present---meaning it can blow up in the cylinder or hose and so a flashback arrestor is MANDATORY!

Oxy-fuel gas systems have the possibility that high pressure O2 can work it's way "upstream" on the fuel gas side so a flashback arrestor is MANDATORY.

Propane air will NOT blow up in the hose or tank as there is no oxidizer present and propane is a stable gas so a flashback arrestor is *NOT* MANDATORY!

Find whoever told you otherwise and find out why they are misinformed and what else they may have told you wrong!

[Thaddeus]

Anyone want a Forgemaster two burner forge?
It has the virtue of.... well its big.

I agree that the t-rex is the way to go.
I just went through most of 40lbs of propane on two knives and some assorted futzing about with hot metal.
I now dont have enough static pressure in the tank to run the forge so it flames out and backfires.
So the 40 pounder goes on to the grill and a couple of 25 pounders get ganged together.

Grumble grumble, shoulda built my own and saved the money.
Well its a good flame thrower for architectural stuff. It is just hugely overkill for a knife making forge.
Which sort of goes to prove the question on the other thread about a forge that is good for everything.
The answer to which is a coal forge, because you can purpose build your fire, but then there are the maintenance and environmental issues.

[PatternWeld]

I have a 3 burner forge and reach high welding temps at 8 lbs of pressure.

I use a 100# tank and it lasts me a week of the forge running 8 hour days.

Something isn't right here.

[woodwose]

Thank you all very much for the advice on forges and everything. The T-Rex came in the mail last week, followed by a crazy hunt around town for the right regulator (ended up ordering on from amazon , where I do not need a propane/gas license to by a damn propane regulator)
"I'm looking for a high pressure propane regulator"
---"what are you setting up?"
"a propane forge"
---" uhhhhmm.... a what?"
"a forge that burns propane"
---" "
"you know, heat the metal, smack it with a hammer... make some... horseshoes, or maybe..."
---"do you have a propane license?"

yeah, those were a fun couple of days, but its over now and I got to spend today working on a bunch of projects that had been set aside because I needed a forge to continue work on them... got to anneal some repousse projects, and have a couple nice trammel hooks started.

[Krag]

I use a Goss 0-60 psi regulator with gauge. I typically run it in the 5-12 psi range through a homebuilt 3/4" single burner. I wanted a 0-30 psi one, but couldn't find one.

Every now and then when I host a forge-making weekend I chuck up a burner in a vise to demonstrate tuning and run it at about 30 psi. Don't be within 10 feet of the front of it!

[Thomas Powers]

So did you try asking them for a "red Hat" regulator for your turkey fryer? (that you plan to use to deep fry some catfish and hushpuppies in this summer...)

[Krag]

Couldn't find one with an integral gauge for a price I was willing to pay!

I'm on the coast now, no more catfish...the blacktip sharks are in, though!

[Thomas Powers]

Yes but all the small turkey fryers that have been so popular use a propane regulator that is quite sufficient for the typical propane forge. I keep an eye out for them at the fleamarket and buy them cheap just for the regulators when they show up.