Propane Forge Inside Shop

MBB

MBB

Joined
Apr 18, 2014
Messages
244
Hi!

I've been lurking on this forum for a several years and have made a few of my knives for myself. I built my own propane forge a few years ago which worked well but have since moved more towards stock removal because of the setup time of having to forge outside my shop. I would like to start doing more forging, but rarely have the time to lug my forge/anvil/paraphernalia outside. For those of you using propane forges inside your shops (as I've seen in multiple videos), how do you avoid burning/sooting the roof of your shop? Also, what do you do for ventilation? Box fans in windows? How about sparks/hot metal flying about during forging?

I'm about to expand my shop about 20' in length (fully enclosed, HVAC, slab floor), so I'm thinking about the option of forging indoors if I can do so safely.

Thanks,

Mike
 
Hi Mike. I don't have an issue of sooting the roof. If you're getting soot, you don't have enough air in the mix. Propane should burn very clean. I have a box fan by the door blowing in fresh air, and as far as burning my roof, I have another hanging fan that blows the hot air rising off the opening of my forge, but I also work in a make shift building with a tarp as a roof. I'll be moving into a 40' sea container in the next few weeks as I get it set up. Taking delivery hopefully Monday. My plan is to set my forge on a steel rolling cart during the hot months so I can roll it outside. My anvil will be sitting right inside the main doors. I'll be able to move it out with a hand truck. When I get a real anvil hopefully in the 250# range I'm going to build a jib crane I can lift it with and swing it out side with, set it down, and then be able to close the doors back up. I won't be able to move it with a hand truck once I get a real one as the pecan stump I have is already close to 350#.

shipping container jib crane.jpg
 
My forge and anvil are in the front of my shop near the double doors, first to be near open air and second because that portion doesn't have a ceiling, it goes up to the roof.

I have a fan in the window in the other end of the building when there's no breeze.

I however wouldn't even be able to tell if I was getting soot up there.
 
In my last shop I would just open the man door usually the great diffrence in tempature from outside to inside would circulate the air but it was a very small shop (12'x22'). My new shop is 20'x40' and the forging area is going next to the roll up door. One thing you need to remember is burning propane creates a lot of moisture in the air so any steel that is cold will sweat and rust. But one question for you is how low is your ceiling?
 
You shouldn't get soot, that's a problem.

You will however create huge amounts of CO2, which isn't itself poisonous, but you need to be careful in a sealed shop, because it displaces oxygen, and can kill you under the wrong circumstances. Even with my windows open, and a couple of roof blowers, CO2 will hold at 5k PPM in my shop, when I'm running my big ribbon burner forge, making damascus. Typical ambient levels are around 400.


Course, we're talking about a huge welding forge, it also is around 120 degrees F after the first couple of hours, even with all the doors open, fans blowing, etc. A small single burner 2-brick forge or something like that, I wouldn't be concerned about very much, just crack a window. It's similar to running an unvented propane heater.
 
Our primary building is fairly tight, 1200sq/ft. gabelroof, open rafters. 6-7' directly over the big forge (what has no dedicated ventilation) rafters never get over 150°f. And thats after several hours running. A squirrelcage exhausts in the peak. Enough leakage thru the gaps & leave a door ajar when running. CO / CO2 is no problem.
Sometimes, burn coal inside also, the hood is good but wont catch it all.
Walls are sheetrock & firetaped, caulked baseboards. Its tight against errant sparks hiding in any gaps.
Soot/dust, Ha!! Its a freeking Smithy...
If you grind, forge or weld, its going to get dirty.
 
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Thanks for all the great replies!

I understand the mess forging makes (to a degree), I just like to ask experts their experiences especially where fire is concerned. I'm working in a residential shop that's a detached garage from my house, so burning that down would not make my wife happy.

BTW, I moderately overbuilt my forge (oversized mailbox, three venturi burners, kaowool/soft firebrick insulation, satanite/bubble alumina lined) which is why I am concerned about heat issues.

Mike
 
My forge is in my detached garage. I have no issues with soot. My forge is a 3 burner Majestic. I keep the garage door open as well as a side door when the forge is running. Do not run a forge with the doors closed. If you plan to forge inside a closed shop, plan to have a robust ventilation system. When I thermal cycle or quench I do it in a tank located by the garage door or just outside on nicer days. The floor is concrete but I am still very careful to avoid any situation that can result in a fire. I have several fire extinguishers withing arms reach and the garden hose is a few steps away. The quench tanks have lids to smother any flare ups which are not usually too dramatic anyway. My forging does not generally result in hot sparks or scale flying everywhere.
 
i use my propane forge at the front of my garage, open the door halfway or so
use a fan from the back about 8 feet or so blowing air across the top of the forge, blowing air out
never had any problem
like Marc said - I also have several fire extinguishers within arms reach and the garden hose is a few steps away.
 
It should not be an issue with proper ventilation andf a properly running forge..

Some things rarely mentioned are:
Have two or three 20# fire extinguishers.
Install a smoke detector that can be enabled when the shop is unoccupied, and turned off when the forge is running.
Installing a CO detector is a must in a closed shop that runs a forge. Installing a CO detector that also has an oxygen depletion alarm is even better. There are units that also monitor the CO2. The extra money for the better units is money well spent.

Dehydration is a far greater risk than suffocation or CO poisoning. Good air flow to keep you cooled helps. Drinking a liter of water or more for every hour at the forge is important. When the shop hits 100F, you are in a superheated environment, which means your body can not regulate its temperature anymore by heating it. After a while your core temp will start to climb. Wearing a cotton tee-shirt is better than being bare chested. Drinking lots of water allows perspiration and the airflow over your wet shirt will create a drop in temperature due to evaporation. When you notice you stop sweating .... get out of the shop and into a cooler environment immediately. Yo are in the early stage of heat stroke, which can be fatal. Same thing for suddenly feeling cold and lightheaded in a hot shop.

I don't know why this didn't post yesterday when I added it????
 
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Thanks! I really appreciate the experience you guys share on here. It has helped me tremendously.
 
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