Cold weather interfering with my forge work

Well, it's getting cold and wet here in DC and I'm beginning to realize
I've got a problem (I'm not known for thinking ahead). I've built my
blacksmith shop in my single family home garage, and when the weather is
like this, I find it very difficult to motivate myself to go out and work
in the cold. But seeming I'm actually trying to get a blacksmith business
off the ground, not working for the winter isn't an option.
I'm using a gas forge with no sort of external ventilation in the garage.
So I just keep the garage door open. But now that it's getting cold, I've
been shutting it partially - and haven't died yet. :) But as it gets
colder, that's not going to work - and it sucks having to wait hours for
the heat of the forge to warm up the garage.
The wife won't allow me to actually close off the garage and convert it to
a closed shop - she believes she's going to get her car back in there this
winter! :) But I could keep it closed most the time and add some electric
heating to take the chill out - like in the 50's. But I have to figure out
how to use the gas forge without filling the garage, (or worse - the house)
with deadly gasses.
Have any of you found solutions for making a garage a nice place to work
when it's cold outside (and cold in the garage)? Have you added some type
of heater? What do you do with your gas forge in the winter?
Have you found a way to deal with the exhaust gasses of a gas forge in a
closed shop? Would a small ventilation fan like for a bathroom provide
enough air circulation to solve the problem (assuming there was some path
for fresh outside air to get into the garage)? Anyone have a clue about
BTW, the garage is part of my two story house and though there is no living
space above the garage, its attic space does connect to the attic of the
I do already have a CO monitor in the garage as one safety measure and it
has not yet gone off while I've been using the forge.
Reply to
Curt Welch
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I wish I could have cold and wet, it's testicle frying time in Australia most of the year.
I find that when it's cold-ish the forge heats me up real quick.
As to gas, they should be burnt up, if you have unburned gas that could be a problem... what kind of forge are you playing with (photo?).
I don't think you'll have a problem.
Regards Charles
Curt Welch wrote:
Reply to
Hi, Curt. I think a mahjor problem will be rust! A major biproduct of the gas forge is water vapor, and I think that you will rust everything in sight if you don't vent the forge well. I am glad that you have a CO detector. But, you still have to deal with CO2, so you DO need a vent of some sort. How about a kitchen wall type of powered ventilator? Put it in an outside wall as close as you can get to the gas forge. Unfortunately, this will take a lot of the forge's heat with the exhaust gases. Maybe use an radiant electric heater at floor level to put some warmth at leg-level. Maybe that's only an issue for us old guys. Up here in Wisconsin, everyone just puts on their Car-Hartts
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; the bib overall kind is real popular, and their snowmobile boots.
Pete Stanaitis ------------------
Curt Welch wrote:
Reply to
Yeah, and swinging the hammer warms me up as well. It's not long before I have to start taking layers of cloths off. But that's been true when it was just in the 40's outside. When it starts to get down below freezing, I'll be looking at a different level of comfort.
It's a single burner forge I made out of Sears Craftsman Air tank and parts from Larry Zoeller including his zburnner
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. Pictures of my forge and garage shop here..
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Well, the question is how much CO2 (and reduced O2) can build up after hours of use if I don't install some ventilation and what dangers do I face not realizing what's happening until I pass out?
If I just get light headed or develop a headache and then have to open the door to get some fresh air, that's fine. But if I risk passing out before I realize what's happening, then that's not so good. :) I don't really fully understand the health risks I'm looking at here. But a healthy forge fire burning in a closed building for hours doesn't sound very wise to me.
The garage ceiling does have an access panel to get into the attic area above the garage, and that attic area is vented to the outside with roof vents (I think). Maybe just installing a fan in that access panel along with some vents in the garage door to let air in will create enough circulation without wasting too much heat?
Reply to
Curt Welch
Interesting point.
The outside wall is brick veneer and I'm not sure I want to put a hole though it for ventilation. But maybe I really need to...
It's an issue for me. :)
Yeah, it's not hard to dress up and stay warm. And we have it a lot easier than you guys must have it up there in the winter. But working in a shop fully dressed for winter cold is not really my idea of how to make a good creative environment for fine blacksmith work. I want to be able to work in a T-shirt and not freeze my fingers picking up cold tools.
Thanks for the ideas.
Reply to
Curt Welch
Looking at those pictures (nice by the way).
With the garage door open you'd have no problems.
With the door closed you definitely need a window. It doesn't have to be a picture window, maybe a way to keep the door half open?
The problem with roof fans is that they really only work if there's air flow, otherwise you cause negative pressure. Maybe in conjunction with the door being half open?
Regards Charles
Reply to
IMHO, whether you choose to actually do so being up to you...
You should have an exhaust hood down to a few inches above your height, or 6 foot 6 inches if you want to pick a "standard" floor clearance value (like in a restaurant kitchen - rather similar in some ways over a big stove and over a forge - lots of fuel exhaust gas - you at least have less grease buildup than they do). You also need fresh air intake adequate for both the exhaust and the fuel gas being burned.
The good engineering - not too cheap (but perhaps not so bad if you cobble something yourself) would be to have the exhaust air and the intake air running through an air to air heat exchanger (such as a long duct inside another long duct - or read up on the way direct-vent gas heater pipe works, which is very similar - twin-wall pipe with air flowing in the annular space, and exhaust flowing out the center). This probably more than you intend to do, but you should think about it, because it's really the way to get what you want.
At the outside, you need to run more duct/pipe to keep the intake air from sucking in the exhaust gas - ie, run the exhaust pipe up and the intake pipe down or sideways. Best results for the heat exchange are from the airstreams going in opposite directions. Also best if the intake air is being blown in and the exhaust gas is being sucked out - reduces the likelihood of any leaks recirculating exhaust gas. At the inside of the building, run the intake air away form the vent hood and distribute it - your setup would appear to suggest a hood in the center, and distributing intake air around the walls. It won't exactly be hot, but it will at least be warmed, to a greater or lesser extent depending on the effectiveness of the heat exchange.
IMHO, you want to avoid the "typical" household air to air heat exchangers, as they often have paper or plastic cores. Metal seems best in this application.
A different DIY approach would be to run the exhaust air though a series of car radiators from the junkyard, and the intake air though another series of car radiators from the junkyard, and pump antifreeze through the radiators to move the heat from the exhaust to the intake. Air to water (antifreeze) to water to air. Or you can get real HVAC heat exchangers with your lottery winnings.
If you don't do something like this, you are inevitably blowing a lot of heat out of the building to get adequate ventilation. Ultimately you will probably also want decent insulation all around, and adding a few inches of concrete to the slab with embedded radiant floor heating tubing is the best solution to the cold feet issue, short of moving further south. Of course, if the slab isn't starting with adequate insulation underneath, the radiant heat in the slab will eat more fuel than it should, but ripping it up to "do it right" is generally too expensive. You certainly sound like you want a heated shop, and if that is the case and your business can support the bills, you should consider going there. Even if the thermostat is only set to 45 or 50F, it makes a big difference when it's cold out.
Not that it will apply to your current situation, but my present ironclad rule is that if there is the remotest possibility that I will ever retrofit (to heat) the building (or add a building to) a slab I'm pouring, it should have the tubing and underside insulation put in - just as "more reinforcing steel is better" - you can't add it later, or not easily. But it's very easy (and not too costly) to put it in place before the concrete is poured.
Reply to
If you close it off, be sure the house is closed tight! Then positive pressure the shop - and have the forge stack take the outflow - and not invade the shop. The fan can be across the room where you can get outside air to compress in the room - e.g. more volume in put than the forge stack and walls leak.
Curt Welch wrote:
Reply to
Martin H. Eastburn
Yeah, the forge puts out very hot air (a few hundred degrees no doubt) and if I use a hood to catch that directly above the forge it could end up with some very hot air in the exhaust tubes. Paper or plastic near that hot air would not be wise.
Lots of great ideas. Thanks. I really like the heat exchanger ideas because I suspect you are right that without them, to get enough ventilation I will be sucking all the heat out of the garage and filling it with the cold air I'm trying to escape from.
I was running the forge for about an hour today with the garage door open about 6 inches. That not only creates the gap in the bottom, but opens a gap at the top of the door as well. It wasn't all that cold outside, but inside the garage, the temp started at about 50, and was about to around 57 in an hour (measured about 3ft off the floor). It was clearly warmer higher up. But though the air didn't seem too bad in terms of gasses, it was clearly developing a smell that made me suspicious of the health quality. The garage has an 11 ft ceiling and I didn't attempt to climb up a ladder to smell/test the air higher up which no doubt was where more of the warm/bad air was accumulating.
I've very limited in what I'm willing to invest because my goal is no to keep my shop in the garage. If I can make the business generate enough income, I want to set up a real shop somewhere else. I don't have enough land to build a shop at home (the zoning set back lines run near to the house all around), not to mention trying to get real zoning for full on metalshop business would never fly. I'll probably not try to make this work as a real business for more than a year, so I'm really only talking making the garage work for this winter - another 3 or 4 months or so. So I'm clearly not going to tear up the slab and rebuild a shop that only has to keep me warm for the next three months. Though I might have a similar issue to deal with whether I end up moving to. :)
But if I can rig up some type of heat exchanger using pipes inside pipes with some sort of hood over the forge that might do the trick of adding enough ventilation while not having to spend a fortune heating all the dead cold air I would be sucking in. And I also have done a bit of welding in the garage over time, so if the same system could help ventilate welding fumes that could be a double win. I tend to do a lot of my welding with the garage door mostly closed simply to protect my neighbors from the arc flash - but I have to pause and air out the fumes on a regular basis when I do that. With heat-exchanged ventilation, at minimal, I would be able to run longer before pausing to air out the garage.
The other option of course is just keep the garage door open enough to get circulation and grin and bear the cold until the warm weather returns! After all, no one said being a blacksmith was going to be an easy life! :)
Reply to
Curt Welch
Yeah, sounds wise. Don't want a set up that could end up leaking exhaust gas into the house!
Reply to
Curt Welch
Yeah, that's how I've been using it for the past month or so since I built the forge. So far, I've kept it near the open front of the garage to help it ventilate out the wide open door.
The door is controlled by an electric opener and it works fine to stop it at any point in the cycle. That's what I've been doing so far as it's been getting colder - just running it with the door about half way open. But as it gets down to freezing and below, that's going to make for a very cold workshop. When I'm standing in front of the hot forge, or hammering on the anvil, that's not really so bad. But I also spend time away from the forge and anvil either doing welding, or fab work, or cleaning and organizing, or design work - none of which is too fun in freezing weather. The more clothes you have to wear, the harder it becomes to work.
Yeah, if I add exhaust ventilation, I have to create a path for fresh air to get in as well. The simple way would be to crack the garage door open a bit.
There's a side door to the outside in the garage as well I could open.
But the heat exchanger idea posted by Ecnerwal is far more interesting and I think it will be required if I want to get both adequate ventilation and not spend a fortune heating all the cold air I would be sucking into the shop.
It would be a shame to be burning up all that propane and having all the heat pumped outside while having to spend a fortune on electric heat to warm up the freezing air I was sucking into the shop.
Thanks for your comments!
Reply to
Curt Welch
I forge outdoors, where my gas forge and anvil are located. Right now we have a beautiful brisk weather, 23 degrees F or so. Did some blacksmithing today with kids playing around. I like not having this stuff in my garage shop.
Reply to
You are more of a man than I am! :)
Reply to
Curt Welch

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