What do you wish you knew before using a Gas Forge?

SpankySmith · May 12, 2014

So I've been all over the web researching gas forges, my new one is ordered and will arrive tomorrow. I've seen lots of postings about propane tanks freezing up, the proper way to ignite the thing, figuring out why yours is leaking gas, etc. But there's no substitute for experience. So my serious question - what do you know now that you only learned from actually USING a gas forge, that you wish you'd known before hand? Any tips/tricks will be appreciated. I'm not "failing to do the research" here, I've done that rather extensively. I just want to lean on some of your wisdom. If you had to pass down a few tips to a newbie Gas Forger, what might they be?

Viking · May 12, 2014

Which forge did you get? From where and why? I'm looking for a gas forge right now as well. It seems the good ones are about $100 above my budget and I am not capable enough to trust myself making one. Cheers, Viking

SpankySmith · May 12, 2014

I am in exactly that same boat! Everything was at least $100-200 over my budget, finally found one online at a price I could afford, it got good reviews when I researched it, but best I can tell it's some guy in NC making them himself as a side hobby. Wilder's Forges. I just did not want to build one myself, though I am quite capable of doing so. Maybe down the road, but for now I wanted one I could just hook gas to and go. Also I was leery of the cheap ebay forges because they seem to all be China made and the opening size on them isn't very impressive. I wanted something flexible enough to do small work AND some larger work (think scrolls, gate pieces, etc). But the pickin's are slim on a limited budget. Gave serious consideration to Diamondback, but again a bit beyond my budget, which has been severely stretched already in just setting up my tiny shop.

I looked at local Forge Councils, but at one time the one nearest to me WAS making them (not anymore) and the one second nearest to me is GOING to make them someday soon but not yet! agggh!

swedefiddle · May 12, 2014

Good Morning,

There is a good book available that covers a lot of the safety and explanation of what is going on. I have it at home, but I can't remember the title.

Propane that we use is ONLY the gas, not the liquid. The gas draw is related to the surface area of the liquid. Residential or industrial propane tanks lie on their sides, so the surface area is greater. We CAN'T lie our bottles on their sides, without picking up the liquid (VERY DANGEROUS). What we can do is to use a T-fitting on one tank and couple 2 or 3 tanks together, to create more surface area. If we use one tank and draw off more than that surface is comfortable with, the temperature of the liquid propane lowers. Liquid propane becomes solid at -40f. If we see the propane tank freeze line on the outside of the tank, put the propane tank in a garbage can or larger pail, that has water in it. The water creates a HEAT-SINK and draws away some of the cold, until it freezes up. Might be a place to keep your soda-pop cold. :) When it is frozen, it is past time for you to take a break. STOP!!

Purchase the book, it is worth GOLD!! :) :)

Neil

SpankySmith · May 12, 2014

What book?! LOL, ya' gotta tell me the title!

Jacob Nothstine · May 12, 2014

Make sure you forge away from the forge. I did a hot cut one day and almost drop a piece of hot metal on the forge gas line. It would have been real bad.

Look up, almost melted a light that was hanging over my forge.

Make sure you wear a leather glove when you start it, mine shoots flames out the front at start up.

It also take my brick forge about 30 - 1 hr to cool down to the touch, fire bricks get hot and stay hot for a long time.

A lot of good safety information on this web site, I would look it over, even if it's for a coal forge.

Good luck.

John McPherson · May 12, 2014

"Gas Burners for Forges, Furnaces & Kilns" by Michael Porter, usually about $20 and up on Amazon.

For the price of one BBQ propane tank fill-up, a wealth of information.

Don't put it on a wooden table or painted metal table, unless you cover the table with brick, and then put a couple more bricks under it for a stand-off if it does not have 4" feet. The bottom gets HOT.

Flexible wire conduit over the rubber hose is a good barrier to dropped tongs, projects, etc. that **want** to melt thru.

Put your forge up about chest to eye level to keep the 'dragon's breath' away from you when doing small items. Easier to keep an eye on your projects, too.

And yes, heat rises. Keep away from rafters, low limbs, tarps, etc.

SpankySmith · May 12, 2014

I have a metal cart that has a wood/press board top, on top of which I've placed 12"x12" tiles, on top of which I plan to place several fire bricks to support the forge. Is that sufficient protection or do I risk the press board combusting?

Jacob Nothstine · May 12, 2014

Make sure you check for gas leaks in all the fittings. Here is a link that shows how.

http://www.propane101.com/checkingforgasleaks.htm

John I like the Flexible wire conduit idea will have to pick some up.

SJS · May 13, 2014

Spanky that should be sufficient;-)

swedefiddle · May 13, 2014

Spanky, Why would you want to use wood or press-board????? I know, the Vikings did!!!!!

Why push the envelope?????

$0.02 :) :)

Neil

SpankySmith · May 13, 2014

Utilizing what I have, a small tool stand that's all metal except the top. Thats why I lined the top with thick tile and fire bricks. Put wheels on one end, a handle on the other so I can move it around as needed.

Chinobi · May 13, 2014

Position your anvil and tools in such a way that allows you to pull items out and get to work on them without keeping your body too close to the dragons breath, you don't want to be in close quarters with it, especially if you have to bend over to grab a dropped tool or a hammer stashed on the floor. Makes it a lot more pleasant to work when you don't have a huge fireball right next to you while you are already hot and hammering!

Simple trick to keep long rods cool enough to handle is to put them in the forge at as much of an angle as possible (while still heating where you need it heated). This keeps more of the rod out of the direct path of the dragon and out of the 'line of sight' of reflected IR radiation from the interior. You can also look up 'air curtains' or use a wet rag and a dipper to keep it in check. Of course if your forge doesn't throw much of a dragon then you don't need to bother :)

SpankySmith · May 13, 2014

Chinobi, nice tip about the angle into the forge. Thanks. Like the flexible wire conduit cover idea too. See?! These are the kinds of "been there, done that" tips I can't find by looking up "forge safety" - they come from experience. Thanks.

Michael · May 13, 2014

Longer tongs, especially longer pickup tongs to get small pieces out of the forge before transferring them to tongs that grip the work better.

Knowing where the fastest, cheapest place to get your propane tank refilled/replaced

SpankySmith · May 13, 2014

We have a local Ace Hardware that fills up 20lb tanks for $16.29. I have no reference point for knowing if that is a good price? I'd rather support my local small business owner than the huge big box locations that would fill it.

Jacob Nothstine · May 13, 2014

That is a good price for tank fill ups.

I would add a stand for supporting long stock.

http://www.homedepot.com/p/PORTAMATE-Adjustable-Pedestal-Roller-Stand-2-Pack-PM-5080T/205037750

SpankySmith · May 13, 2014

Hey, for once something I already have! I've got one of those stands, used it for woodworking for years, it won't mind being re-assigned to the Forge.

ThomasPowers · May 13, 2014

As both my currently in use propane forges use firebrick stacked to provide the front wall/working opening making a set of "Hot Brick Tongs" was a big help to reconfigure on the fly or to close up the opening when annealing, or to pick up bricks knocked to the floor, etc.

I also forged a set of Ti tongs as the heat doesn't transfer up the reins as fast as with steel ones.

Frosty · May 13, 2014

If you don't have flammable stuff around the shop floor lighting without losing eyebrows and arm hair is easy enough. Light a small wad of paper, toss it into the forge and SLOWLY crack the valve open. You will get paper ashes blowing out of the forge mouth but if your shop is reasonably fire resistant it's easy to take care of.

Long handled light tongs are a good thing as are helpers. Placing work at angles to keep the dragon's breath from heating the whole shebang is a must. That is a fact of gas forges, anything even close tot he opening will get hot, anything.

I made a floor extension for mine so there is a fire brick "porch" in front of the openings it wasn't a lot of help holding long work so I made a telescoping helper that extends maybe 18". The helper is also really handy as a tong rack. The "porch" thing works best for holding pieces of fire brick to help redirect the dragon's breath away from the stock I don't want hot.

Your cart as described will be fine, that's plenty of heat shielding. A piece of concrete backer board on spacers is usually plenty unless the forge doesn't have legs at all.

You've read about adjusting the flame right? I'll just repeat myself much as I hate to.<snicker> One of the biggest complaints about gas forges is you can't weld in them because they scale up the steel/iron. That is an issue of improper fuel air adjustment. This is where one of the MAIN the safety warnings will come in.

Ideally you want a stoichometric burn, that means the air and fuel are balanced so all the fuel and oxygen are consumed in the fire, neutral is the common term. Unfortunately it's not an ideal world, the flame will cause all sorts of strong flows in the forge chamber and will entrain fresh air from the door making oxidizing conditions in places. The way we counter this simple fact is by adjusting the fuel air ratio to be a LITTLE rich. The easy way to judge is by gauging the "dragon's breath" coming out of the forge door. You want a little orange flame, sometimes it'll have a pinkish tinge I don't know why but it's usually an indication it's bordering on too rich but that isn't written in stone. Yellow fluttery flames is bad anywhere in the system, WAY too rich. Blue dragon's breath is bordering too lean and is likely to scale your work IN the forge.

Okay, here's the safety part. These forges WILL generate exhaust gasses not the least of which is CO, Carbon Monoxide, while not toxic as such, it bonds much more strongly to hemoglobin than O2 so we tend to suffocate by breathing enough and enough isn't all that much. Good ventilation and good burner adjustment is a MUST. The richer the flame the more CO is generated, excess CO is what keeps the steel from oxidizing in the forge. So, yes we the noble blacksmith are deliberately generating CO in the shop. CO2 generation is also occurring but isn't nearly so dangerous, simply getting some fresh air will flush CO2 from our blood, not so CO. Another dangerous exhaust gas is NO2 though in limited quantities a hot enough forge will generate some.

By far the most common exhaust component is water. Extra water in the air isn't going to poison anybody but it sure isn't good for tools. A good aspect of all the water generated by combustion is it tends to scavenge some of the other noxious gasses, that unfortunately tends to form acids, carbolic and nitric. More badness for things like machine tools but not a health hazard.

Check for gas leaks with soapy water, if you use a match we're going to make fun of you forE-V-E-R.

Don't use teflon tape in the plumbing, if there are leaks use the paste. Quality brass and tapered pipe works just dandy, mine hasn't leaked at all in a good 20 years. Propane isn't a small molecule so keeping it trapped isn't a magic trick, I find moderate tightness does the trick.

Valving, do NOT rely on the tank valve in an emergency, put a 1/4 turn ball valve between the regulator and the forge, mount it right behind the gauge so you can shut the gas off with a thrown rag or a fast slap. I prefer the 1/4 turn ball valves with the stop on the handle so no matter which way you turn it it will stop in the OFF position. I've never had an emergency I've needed to do a FAST shut down but safety is a place where my basic philosophy rules. "It's better to have it and not need it than need it and not have it."

Frosty · May 13, 2014

Propane is heavier than air, WILL collect in low places and wait for a source of ignition. I've never seen it but have heard of an occasion where propane collected in the grease trap in the shop drain. The bang just lifted the cap a foot or so and scared the crap out of everybody. Lesson learned though, I sure keep my eyes open for low laying gas traps.