sfDuck Posted August 31, 2007 Share Posted August 31, 2007 I have been puzzling the possibilities of making a gas forge in my cellar. I have 8 ft clearance cement floor and 2 ft thick stone walls. Since I'm putting in propane anyway and I have a 7 in chimney just stairing at me, what size vent do you use for a gas forge. Its warmer in winter than the wood barn. But my concerns are the dust in the house and fumes. Coal forge in the barn in winter aein't warm nuff.......Duck Quote Link to comment Share on other sites More sharing options...
Blacksmith Jim Posted August 31, 2007 Share Posted August 31, 2007 From what I hear, propane gas is heavier then the general air around us. So it will settle into low spots. I've heard a lot of people caution against using propane in basements or other below ground areas... Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 31, 2007 Share Posted August 31, 2007 There are a number of risk factors you need to consider before putting a propane forge in a basement. As said, propane is heavier than air, will settle in low spots and launch portions of the house if ignited. The other really serious danger is CO. (carbon monoxide) A propane forge produced prodigious amounts of CO gas, it is odorless, colorless and toxic in the sense that CO attaches itself to the hemoglobin in your blood displacing oxy. It's also pretty insidious and will creep out of the basement and into the rest of the house. At the very least you'll need a serious ventilation system to remove unburned propane and the CO. Co isn't as much heavier than air as propane so it'll rise if heated as in the forge. When it cools it will settle but not before finding it's way into upper floors. CO detectors are a must. If I were in a position to have to use a propane forge in a basement I'd build it a booth with exhaust system above and below the openings. I'd plumb the propane in from outside directly through the wall into the booth. I'd have so many CO detectors visitors'd think I was decorating with them and a propane sniffer. (whatever they're called) You can find the gas sniffers at boat suppliers or call the local propane guys. Given any choice I wouldn't do it. I'd rather borrow money and insulate the shop or build a big honkin wood stove. Frosty Quote Link to comment Share on other sites More sharing options...
Dodge Posted August 31, 2007 Share Posted August 31, 2007 Certainly going to get dust! I have considered this question (about fumes) inside my garage. I live in a split-entry where the garage is under bedrooms. Right now, my forge is on wheels and I roll it outside, but If I didn't rent I would build a stove hood like in a commercial kitchen with perhaps an exhaust fan in the hood. And yes, I forgot about the co detectors. I have one, I just take it for granted as it's never gone off :) Quote Link to comment Share on other sites More sharing options...
sphughes Posted August 31, 2007 Share Posted August 31, 2007 I ordered myself a Chile Forge Tabasco yesterday. After speaking with Dave there, I felt it was the right move for me. I'll post some pics after I get it. -Scott Quote Link to comment Share on other sites More sharing options...
sfDuck Posted September 1, 2007 Author Share Posted September 1, 2007 Thanks for all the comments guys. First off propane is only as safe as you make it. Pressure test it to what ever pressure you can achieve with air then leave it for an hour or more,(use a pressure installed on the line) and see if the pressure drops if it does check for a leak with water and a little dish soap using a small paint brush. If the pressure does NOT drop you did it right. From what I can guess from the comments, gas forges do not have any venting or chimney. So most gas forges should only be used outside. That being the case I'm thinking of building it like a boiler or pool heater with a chimney on the top. What is the usual pressure used on the propane and the size of hole on the burner? That will determine the right size of venting. Since I have a 7 in. chimney I will work backwards from chimney to the size of the burner and then see if that is big enough to heat the steel. Thats a lot of research and I still have not decided if it is workable. Your input on these ideas will really help, thanks guys.........Duck Quote Link to comment Share on other sites More sharing options...
sfDuck Posted September 1, 2007 Author Share Posted September 1, 2007 Oh, I'll have to find my old regs book to find to the right tables for btu's and sizing. I also still have my CO2 & CO tester at $10. a test. ..........Duck Quote Link to comment Share on other sites More sharing options...
Daryl Posted September 1, 2007 Share Posted September 1, 2007 I also work in the 'patch. My repairs frequently include stuff with liquid Nitrogen, liquid CO2 and other stuff where CO and H2S detectors are a must! While at first, these detectors seem quite sensitive until one has an understanding as to how dangerous gases are. If you are going to set up in your basement, I urge you to buy a permanent CO2 detector for that airspace. Mistakes of that nature are not habit-forming. Quote Link to comment Share on other sites More sharing options...
sfDuck Posted September 2, 2007 Author Share Posted September 2, 2007 Already have one just waiting to install it. ........Duck Quote Link to comment Share on other sites More sharing options...
welder19 Posted September 2, 2007 Share Posted September 2, 2007 If done properly, chimney, co detectors, and making sure your not going to start a fire by being too close to anything flamable, including getting your floor joist too hot. I would recomend a hood over top then into the chimney from that. If it was that dangerous then there wouldn't be propane heaters and hot water heaters, dryers ovens/ranges. It just needs to be done properly. If I wanted or needed a forge in my basement I wouldn't hesitate to do it. welder19 Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 4, 2007 Share Posted September 4, 2007 One other point---where is the makeup air going to come from? Good hood will require quite a bit of replacement air to come into the area or it won't work properly. If you are drawing from the rest of the house and the rest of the house is drawing it from outside your chilling of the house may not be cost effective or appreciated. I'd think of having a forge "enclosure" with a connection to the outside to try to keep from having to use inside air---you will still get radiated heat so your forge may end up as a net heat producer for the house. Quote Link to comment Share on other sites More sharing options...
solvarr Posted September 6, 2007 Share Posted September 6, 2007 Hate to be a twit. In alot of areas your home owners insurance will only insure a house that has 1/2 - 2 PSI devices in a house. Friend of mine had to go through Loyds of London to get his house insured that has an armory in the garage. You may want to look into this. Quote Link to comment Share on other sites More sharing options...
sfDuck Posted September 8, 2007 Author Share Posted September 8, 2007 Thanks for the encouragement welder19, haven't given up just yet; just mulling things around some more. Where i come from theres' two counts to answer at this point, 1. I am manufacturing an uncertified appliance (forge) and 2. will my insurance company still give me house coverage if something happens? I've witnessed a couple of instant combustions, one was 3,000,000 Btu boiler burp and shake a ten storey building. We had to replace a chimney top for a 18" ten storey chimney an some splannin to the local fire dept. There was a fault in a new boiler and we had to have it go through its sequence to find the fault. The foreman and I were sitting astride it at the time. any way the point was I have waltzed with gas before. Thats why I am asking lots of questions and checking tables. What pressure do you run your LP gas on and what size burner oriface? Thanks ...........Duck Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted September 12, 2007 Share Posted September 12, 2007 First question... Do you live alone in the building? If not, what gives you the right to put others at risk? I would not, under any conditions, run a gas forge in a basement. I don't believe any amateur could assure safety, and a professionally installed environment would not include a homemade forge. Even if you live alone, it isn't worth the risk. Also, don't get comfortable because there are propane appliances. The ones that are in general use in homes do not pump high amounts gases into the air (regardless of what they are). Those that might (costruction heaters, etc), are only supposed to be used in non-living environments and with extraordinary venting, and NOT for general heating purposes. It isn't worth the risk! Quote Link to comment Share on other sites More sharing options...
welder19 Posted September 12, 2007 Share Posted September 12, 2007 What pressure do you run your LP gas on and what size burner oriface? My gas burner in my melting furnace has a .023" orifice and I run around 25-28 psi, but I have another one with a #57 drill bit orifice (not sure of the decimal size right off the top of my head) and I run that one around 20-22 psi. The .023 orifice I have is a mig welder tip, which can be bought in most hardware stores or Home Depot and Lowes. Trying to remember off hand, I think they have a 10-32 thread on them, so there easy to use by drilling and tapping a hole and then just threading the tip in, for those who don't have a # drill bit set. There are all kinds of variations of homemade gas burners out there, I will try and post some links tomorrow, also one to a calculator. welder19 Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 12, 2007 Share Posted September 12, 2007 Mig tips are 1/4" - 28. Frosty Quote Link to comment Share on other sites More sharing options...
patrick Posted September 12, 2007 Share Posted September 12, 2007 I have a large home built propane forge that I use in my garage (it just looks like a garage, it really is a dedicated blacksmith shop). My forge is a 2 burner forced air model that can heat up to 300lb of steel at once. It is connected to a dedicated 100 gallon propane tank. I do have a regulator on the line coming in from the tank, but I don't pay attention to what pressure I run. I can tell you that when I asked the propane company about running a seperate line from my existing tank, which feeds the house, to the shop they said it could not be done since I needed much higher pressures at the forge than in the house. That may be a limitation of my set-up and not true for all propane arrangements. From a "catch things on fire" point of view, the ceiling above the forge is 8' tall. I have yet to burn the cieling, but I can melt the sap out of the trusses. I do have Kaowool on the wall behind the forge since it has a rear port. I would be extremely reluctant to run any but the smallest forge in a residence for all of the reasons mentioned above. My forge is not small at all, but I have run mini-forges built from soup cans and a plumber's torch indoors. This will handle stock at least 1/2x1/2, but they are not convienent for large or long work. Also be aware that leaking propane has caused housed to explode. We just had one blow up near me yesterday morning. Our house shook from the blast and we are several miles away. The local authorities did not have a cuase of the explosion as of yesterday morning, but I have heard rumors that someone attempted to light a propane furnace, had trouble and left the house without shutting off the propane. No one was hurt since the house was empty when it exploded. I suspect that given the right precautions and attention to detail you could safely run a propane forge in the basement. But the risk of an accident is real and it only takes one mistake to have a serious accident. Patrick Quote Link to comment Share on other sites More sharing options...
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