Forge from freon tank

[Blueberry]

My first proper forge i made from a freon tank. I made it with the idea that it should have a nice U shape and provide some steel to help conduct heat with the aid of dirt as insulation to keep it from radiating that heat. I also decided to keep the other half of the lid to futher that idea of traping heat, whether it actually helps or not im not sure. 

Im using a hair dryer and charcoal. So far ive used it for a day its working well and its seems more efficient than the hole in the ground i used before it. Just not sure if it will reach weld temps yet or if it will eventually burn through the thin steel.

 

[Jasent]

Lids not needed.  Won’t hold enough heat to make any difference.  Charcoal will straight melt steel no problem, if your not able to you may have too much air which will cool your stock.   Lid looks cool though 

[Irondragon Forge ClayWorks]

Like Jasent said too much air will actually cool a charcoal fire. What are you using to control the air blast?  I can't tell from the picture but what type of charcoal are you using. BBQ briquets are not the best, lump charcoal broken into pieces no bigger than a pecan are what I recommend.

[Frosty]

Welcome aboard Blueberry, glad to have you. Do you have an easier to remember handle we can use? Blueberry is kind of awkward to me but if there's significance for you we LOVE a good story. 

I love the way your forge looks but the lid serves no purpose as a forge. Take a look in the solid fuel forge section, there are all kinds of efficient and inexpensive forges posted. As it sits and burns I'm thinking it'd be an outstanding chiminea for the yard or deck. A number of guys are making chiminea from old propane tanks to look like Minions and they're pretty darn marketable. Sell a few and buy something nice for the shop, hmmmm?  

Check out the JABOD (Just A Box Of Dirt) forge, the basic design is as old as humans have been hammering metal and the current version is actually darned nice.

Frosty The Lucky.

[Blueberry]

Im using lump charcoal. The pipe is 2 inchs in diameter and no control other than low setting on the hair dryer. Would it be best to just use a smaller pipe or a rheostat. Or both? I guess i never realized the blower could also cool the stock.

 

As for the name its just a gamer tag i use. Also that sounds like a good idea since i have a pretty much unlimited access to empy freon tanks.

 

[Jasent]

My charcoal forge the low setting is a bit too much air.  I use a j box to waste some air.  Also using 2” pipe

yes galvie until the vertical pipe going in the forge

[Blueberry]

Good idea guess ill get something figured out to control airflow. 

[Irondragon Forge ClayWorks]

That air gate Jasent came up with is about the best I've seen. One way to controll the air is to detach the hair dryer from the pipe, then just aim it at the open pipe from about an inch away and rotate the blower to only put about half the air into the pipe or aim it straight at the opening for more air. Charcoal takes very little air.

[ThomasPowers]

And profits from greater depth. If I was doing blades in that forge I would put a row of hard firebrick down both sides against the walls, (or adobe!) and fill it to close to the cut line for the lid and use as little air as makes a great hotspot.  (So more charcoal because of depth and less charcoal because of adding a liner.)

You may want to track down some pictures of the Tim Lively Washtub forges used by the neotribals to get some ideas.

[Blueberry]

I put a rheostat to control the blower and I experimented last night trying to forge weld i was able to get the steel to a very bright orange or yellow color. I tried folding a file its kinda sticking on the end thats it. Ill try it with borax next.

Either way i  guess it should get up to temp if i throw a bunch of charcoal in, id assume it all comes down to efficency after that.

[Ramsberg]

There are zones in a fire, closest to where the air comes in, it's oxidizing, that is, there's an excess of oxygen, higher up, it's neutral, where there's just enough and at the top it's reducing, where there isn't enough. In general you want the steel in the neutral part of the fire, if it's in the oxidizing it'll not heat up enough and will develop scale very quickly.

For there to be a neutral and reducing part of the fire, the fuel must be deep enough. Coal can be relatively shallow and give a neutral fire, charcoal must be deeper.

Efficiency doesn't really come into play with a solid fuel forge. For them, the primary heat transfer is via radiation, the heat transfer coefficient from that being determined by the temperature differential between the steel and the charcoal and the emissivity of both of them, secondary heat transfer is via conduction between the charcoal and steel, the heat transfer from the heated are is almost totally irrelevant in a solid fuel forge.

For a gas forge, the convection of the fire to the inner parts of the furnace heat it, then, that heated furnace heats the steel via primarily radiation and conduction, with some, depending on the position of the flame and work to be heated, there will be direct convection between the flame and work.

Basically, with a solid fuel forge, the effective fire that heats the work is pure carbon, and it's temperature potential is hot enough to melt any metal you can get your hands on. The key for it, is having a fire of proper depth for the fuel being used in conjunction with a proper airflow for that fire depth.

[Irondragon Forge ClayWorks]

Couldn't have said it better. There are several threads that illustrate that.

https://www.iforgeiron.com/topic/30887-forges-and-fires/