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I Forge Iron

Can't get heat in my charcoal forge


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Different alloys have different lower and upper forging temperature limits. I've never worked stainless so I can't give you any guidance there.
I have worked in direct sunlight and in my experience, the steel can appear black and not yet be cold enough to regain magnetism. For the simple steel I work with that means in full sun it is still within forging range when it appears black.
I suggest you find some sort of shade where you can better judge color. If that is unattainable then you'll just have to get good and knowing when to stop hitting by the way the steel moves or doesn't.

ron

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I suggest you find some sort of shade where you can better judge color. If that is unattainable then you'll just have to get good and knowing when to stop hitting by the way the steel moves or doesn't.

ron


I agree. If you can't move your forge to a shaded area, create a little bit of shade next to the forge with a bucket turned on its side, a box that's open on one side, something like that. Stick the work in there to get a better idea of its actual color.

Learning how far you can stretch a heat will take practice. Yeah, you'll make some mistakes and ruin some pieces. Don't worry about it!

And yes, don't be stingy with the charcoal. For the sort of work you're doing, you may want to block off a lot of the holes in your Lively forge with mud to create a shorter, deeper fire. If you're working with hand hammers, you can't work a very great length of steel in one heat, anyway, so you won't really lose anything by shortening the fire. Save the full length fires for heat treating.

Bill, sounds good. Let us know how it goes.
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I use home made charcoal made out of the 2 X 4 from the center of pallets or other 2 x construction lumber scraps. My forge will get hot enough to easily burn any nails I left in the charcoal.

Another way to get less air other than a reostate or air gate is to decreas the intake space ahead of the fan. Use a sliding metal or even duct tape over part of the opening.

BAD Roger in Minnesota

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  • 1 month later...

Ok guys I have an issue. I can't get my brake drum charcoal forge to welding temps. I have a bathroom fan for an air supply, 2 inche pipe connects the air supply to the brake drume, on hi the temps are not hi enough to weld. thinking I might be giving it too much air I turned it back a bit, still nothing. the best I can do is in a dark room I get a bright cherry red, just shy of welding heat, I think. I tried to weld a few pieces old strapping and an old hacksaw blade. I could not get it hot enough. any help would be greatly appreciated.

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Ok guys I have an issue. I can't get my brake drum charcoal forge to welding temps. I have a bathroom fan for an air supply, 2 inche pipe connects the air supply to the brake drume, on hi the temps are not hi enough to weld. thinking I might be giving it too much air I turned it back a bit, still nothing. the best I can do is in a dark room I get a bright cherry red, just shy of welding heat, I think. I tried to weld a few pieces old strapping and an old hacksaw blade. I could not get it hot enough. any help would be greatly appreciated.


The more details you can supply the better answers you'll get.
First, can you get pictures of your set-up?
How deep is your fire? Charcoal likes a deeper fire than coal. (I've gotten to welding temps with a fire 4 to 6 inches deep.)
Is your forge insulated? It is easier to get hot if you don't lose as much heat.
How do you regulate your air supply? Can you cut it back more? Charcoal doesn't need very much air to produce heat and too much air can blow the heat out of your fire and make it colder.
When you've cut it back, how does the fire change; hotter, colder, no noticeable difference?

Anything else you think might be important?

ron
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1.First, can you get pictures of your set-up?
I have pictures in the "show me your forge" thread, I just can't find them on my computer at the moment. It is a brake drum mounted into a 55gallon drum, plumbed in with 2 inch pipe to a standard bathroom fan, plenty of air if it is needed let me see if i can pull them off of there
**edited**post-13874-016516100 1279767061_thumb.jp
this it a picture of my forge you can see the dimmer swith, the back of the fan as well as the forge
post-13874-025441900 1279767072_thumb.jp
this is a picture of what my piping looks like inside of the drum
post-13874-032151800 1279767078_thumb.jp
this is the fan I use

2.How deep is your fire? Charcoal likes a deeper fire than coal. (I've gotten to welding temps with a fire 4 to 6 inches deep.)
My fire stays around 4 inches deep, I keep it piles about 2 inches above the rim of the brake drum,

3.Is your forge insulated? It is easier to get hot if you don't lose as much heat.
No not insulated, I think the only insulation in my entire shop is my welding gloves and the kaowool in the "still not working" propane forge

4.How do you regulate your air supply? Can you cut it back more? Charcoal doesn't need very much air to produce heat and too much air can blow the heat out of your fire and make it colder.
I have the fan regulated with a dimmer switch

5.When you've cut it back, how does the fire change; hotter, colder, no noticeable difference?
when I cut the air, the fire get colder. At full power this fan puts out flames from the coals about 6-8 inches high, cut back the air and the flames die back, with the air supply as low as the fan will allow and still turn the coal smolder brightly, with no flames

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Try taking a piece of *NON-GALVANIZED* sheet metal and bend it around so it will sit in your brake drum touching the sides in a C shape and extend up another 6 inches or so. This will allow you to pile it deep! (When I used a brake drum forge as a billet welder I did this and I cut a "mousehole" across from the opening to be able to slide long billets through the hot spot. Also I liked the gap in the C to be just a bit wider than the largest billet will be so it helps hold the fuel in when I pull the billet out to weld.

Also watch the air, too much is as bad as too little!

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Tey taking a piece of *NON-GALVANIZED* sheet metal and bend it around so it will sit in your brake drum touching the sides in a C shape and extend up another 6 inches or so. This will allow you to pile it deep! (When I used a brake drum forge as a billet welder I did this and I cut a "mousehole" across from the opening to be able to slide long billets through the hot spot. Also I liked the gap in the C to be just a bit wider than the largest billet will be so it helps hold the fuel in when I pull the billet out to weld.

Also watch the air, too much is as bad as too little!


I'm with Thomas. You need a deeper fire. Once you've done that, turn the air waaaay back (as in, turn it down to maybe 25% of max), then slowly turn it up and watch the fire. At a certain point a portion of the fire will be near white and uncomfortable to look at. There you go. You may be very surprised at how little air is actually required.
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I'm with Thomas. You need a deeper fire. Once you've done that, turn the air waaaay back (as in, turn it down to maybe 25% of max), then slowly turn it up and watch the fire. At a certain point a portion of the fire will be near white and uncomfortable to look at. There you go. You may be very surprised at how little air is actually required.


I'll try that, I have a few pieces of sheet metal laying around. I'll let you know how it goes once I get it in place
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  • 2 weeks later...

I;ve recently found the air flow rate for the fan I use...that bathfoom fan has a rate of 50cfm. Is this sufficient to reach welding temps? I think so, but I've not welded with a forge yet.


update*** I finnally got my propane forge going, and now I get to learn to adjust the gas vs air ratios to get a good heat on it. But don't worry the charcoal forge is still my number one.

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I would like to add that in addition to a gentle air flow with charcoal you need a deeper fire than with coal, much deeper in my opinion, and with the nice coal forge shown I would suggest standing a row of firebricks on edge to effectively make a deeper firepit. Then if you switch to coal you can remove the firebricks. A deep fire is good also with coal, in using coal you can push it in from the edges and wet it to keep it from spreading where you don't need it. With charcoal its much easier to form up something to contain the deeper fire to keep the heat concentrated.

Anvillain

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