Gundog48 Posted August 9, 2012 Share Posted August 9, 2012 As you probably know due to the number of questions I've posted, I'm trying to finish off my new forge. I'm really concerned with the overheating problem, although the fire cement protects most of the bottom, the stainless steel 'nozzle' is still exposed to the full heat which will heat up the rest of the forge through conduction. I'd like to be able to run my forge on full blast and it last for a few years without having to worry about it overheating. I've read a lot about watercooled forges, and I think that may be just what is needed. The pictures below show how my forge is configured with the fire cement chipped away for a better view. As the pipe is directly attached to the grate, I think that would be the easiest location to cool it and would also prevent the heat from spreading to the rest of the forge as this part would be cooler, thereby 'cutting off' the heat before it spreads. So, what I have in mind is some kind of jacket to fit around the top of the air pipe, with an in and an out which go to an open container of water. The water will pump itself through convection. I just don't know how I would construct the jacket. Maybe some sheet steel carefully wrapped and welded? Perhaps I could buy something? Any suggestions? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 9, 2012 Share Posted August 9, 2012 You should be blowing cold air through the grate on a regular basis helping to keep it cool. Personally I think you are making a mountain out of a molehill. Been smithing for over 30 years and never had to "cool" a forge even here in nice and hot New Mexico. The water cooled tue irons are for side blast forges where the tuyere projects into the fire and is completely surrounded by hot coals Quote Link to comment Share on other sites More sharing options...
Gundog48 Posted August 9, 2012 Author Share Posted August 9, 2012 You're probably right, but after the incident of my last forge I've been pretty paranoid, and I'd just love to think that this is idiot proof! After a couple of sessions the only sign of wear I've noticed is a tiny sign of the surface of the stainless 'melting' which you can just about see in the picture. I just figured that if I can get a WC shroud on the top of that pipe, I'd never have to worry about it, and it would require minimal effort to set up and run. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 9, 2012 Share Posted August 9, 2012 Except for steam problems, freezing and breaking, rusting, keeping it topped off---LOTS more effort to set up and run than just doing nothing! Quote Link to comment Share on other sites More sharing options...
VaughnT Posted August 9, 2012 Share Posted August 9, 2012 Yea, Tom's right. You're making way more out of this than there needs to be. The only problem I see is that the very narrow portions between the holes you drilled will not last very long. Of course, those holes appear rather small, so if they open up a bit that would be a problem. You'll have to replace the fire cement long before you have to worry about the stainless steel being ruined. Heat conduction isn't an issue. Quote Link to comment Share on other sites More sharing options...
DennisG Posted August 9, 2012 Share Posted August 9, 2012 I made my own forge, I used 3/16 or 1/4" plate (old and dont remember), my grate on the bottom is 3/16" round and I have been using it for a few yrs now. I have run straight industrial coke in it for many months because thats all I had at the time. As anyone who has run this type of coke knows it gets HOT. I have used it to forge weld as well as just pounding. Now, why all this info? I bent down to look under one day and noticed my fire pot was glowing a nice red. I kinda freaked a bit and shut down to check my pot to see if there was any damage happening. To my surprise there was no damage, no sign of melting or change in the surface. I went back to using my forge with the coke and never gave it another thought and to this day my pot and grate are all fine, not even any show of wear. Now, I am using Met. coal and sometimes the same coke. So don't worry too much of it burning thru. Besides, I am sure over the next yr or so you will be building a new forge or buying an old one, call it "moving up" the blacksmithing chain of "ooOOO! look how cool that forge is, and only 10$....SOLD" LOL Good luck DennisG Quote Link to comment Share on other sites More sharing options...
Gundog48 Posted August 9, 2012 Author Share Posted August 9, 2012 Thanks Dennis, a lot of people use coal here, it's hard to appreciate just how hot coke can get! Was that 3/16" on the bottom of the whole forge? The problem with mine is that the 1/4" grate part is bolted to 4mm thick spring steel sheet. Perhaps some reinforcing to stop it sagging? I just got some 3/4" steel plasma cut to make a rectangular firepot which will drop in above the grate and then the gap will be sealed with fresh fire cement (that's why it was cut away in the picture). Hopefully the extra mass will help a lot with preventing the bottom from heating up. Kindly remind me, is there some special procedure to welding cast iron? I remember hearing something about preheating- I'm pretty new to this. Was thinking of welding some bar to the cast iron drum, but I suppose I'd better check if there's anything special involved! You're not kidding about great deals of forges! I was looking up water-cooled forges and stumbled across an agricultural auction website. They have catalouges from their past auctions and there was a "water-cooled forge" that sold for £2! There were so many incredible deals! I guess people don't know what some things are worth! Next time there is one nearby I'll be paying a visit! I think I may switch back to coal. Although I burn through it a lot quicker I find it nicer to use. It feels wrong coming off the forge without being covered in soot, and I love the smell of coal burning! For me, it is generally nicer to use, although I'm far from used to either fuel! Quote Link to comment Share on other sites More sharing options...
arcc Posted August 10, 2012 Share Posted August 10, 2012 My firepot normally glows red when I'm forge welding, yet I don't see any sign of damage. I did burn the arc welds out that holds my clinker breaker in yesterday though. However, it held up a while and the welds were actually very small and not deeply penetrated. Quote Link to comment Share on other sites More sharing options...
John McPherson Posted August 11, 2012 Share Posted August 11, 2012 Here is a picture of a thin carbon steel (not stainless) firepot glowing with charcoal 'fire fleas' coming out. No damage after years of occasional use in a museum setting. Quote Link to comment Share on other sites More sharing options...
tomhw Posted August 12, 2012 Share Posted August 12, 2012 I don't think that a fire pot should get hotter than a black heat. A properly managed fire should have the heat focused above the touyer and fire pit. In a properly managed fire the recently introduced fuel insulates the touyer and fire pot from the the burning fuel. Using coke or charcoal requires more attention than coal because of the speed with which the fire spreads through the more pure carbon fuel. Though I am using charcoal now, I prefer coal to coke or charcoal because the smith has the most control of the fire with a good, high quality, bituminous coal. Quote Link to comment Share on other sites More sharing options...
John McPherson Posted August 12, 2012 Share Posted August 12, 2012 "In a properly managed fire the recently introduced fuel insulates the touyer and fire pot from the the burning fuel." ??????????? How's that again? I add fuel to to the top and edges of the fire, green coal becomes coke, which burns up as it settles into the firepot, releasing radiant energy to heat the metal that I place in the burning embers. Some of that radiant energy heats other things, including the firepot. The unburnt ash and clinker settles to the bottom, but not enough to insulate the firepot. The recently added fuel serves to keep some of that radiant energy off of me, but I don't think it is helping the firepot. Claying the bottom of the pan would keep some off the heat off the twyer, and certainly keep the cast iron pan from cracking. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 12, 2012 Share Posted August 12, 2012 Whats wrong with a real cast iron fire pot. What you have built may or may not work properly. More likely it will produce an anemic little fire that will frustrate your attempts to forge efficiently. This frustration may result in giving up before you really even start. Don't reinvent the wheel as a beginner you need everything working in your favor. I have had my fire pots glowing hot I have used up about 3 or 4 so far in 20 years of forging so what. You have to crack an egg to make an omelet. About 2 years I got a real thick cast iron fire pot it shows no signs of wear. I built a forge like what you built when I was first starting out it was almost useless. If I knew what I know now I would have bought good tools right off the bat and not messed around making things of poor quality I could have bought better versions of. I thought I could not afford it at the time but when I look back at how much money and time I wasted things I thought I needed the forge was cheep. Your time is worth something even if this is just a hobby. If you don't have the ready cash sell something you don't use. You may think I am being harsh but it is the truth. Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted August 12, 2012 Share Posted August 12, 2012 I wish to second what Thomas, John and Timothy have typed. Here in the states, we have access to commercial firepots. Perhaps you will find them in the UK. I started forging roughly 25 years ago in a wood stove with a piece of rail for an anvil. As Timothy has stated perhaps the real issue is finding proper equipment. Please don't misunderstand me. I had to be shown my own self. Continue as you wish. These comments from me are just that. Comments. You will find folks here that have indeed experience and perhaps some of have a bit more than others. Please don't put me in group with the experts. I've torn up my share of stuff. I DO have a fair bit of experience. Good luck my friend. Keep us posted. By the way, I have a shop built forge in my shop. 3/16 plate with 2x2 square legs. This forge has a commercial firepod (Roger Lorrance) dropped in the space cut for it. Shop built tuyere and ash dump. Shop built airgate and commercial electric blower. I have shop built forges otherwise as well. Sometimes the thing is, you just need the right stuff to go along with what you have built. Coal and charcoal are my choices for solid fuel but I own gas forges too. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 13, 2012 Share Posted August 13, 2012 As said several times already, you're making WAY too much out of this. The air grate will get hot, no way around it BUT the cold air blowing through it will keep it from melting. On the other hand if you stack several pieces of sheet or plate on the air grate there is too much there to be cooled very well. I'd lose all but a single piece of 1/4" or a little less for the forge bottom. drilling holes as you've done works as laying short pieces of 1/2" +/- with a gap between them for the air grate. One trick that will help cool the bottom of the fire pot as your pic shows it, is to enlarge the air pipe so it covers a larger part of the pot's bottom, the air grate opening will control the final air flow. and blowing into a larger volume will have zero effect on how much air gets to the fire as the air grate opening is that control. And again, enough opining from a gas forge guy. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gundog48 Posted August 13, 2012 Author Share Posted August 13, 2012 I've been reading your comments and have decided I'm massively overreacting! I've never had Quote Link to comment Share on other sites More sharing options...
Gundog48 Posted August 13, 2012 Author Share Posted August 13, 2012 I've been reading your comments and have decided I'm massively overreacting! I've never had it glow red, so I have nothing to worry about! I built my firepot Friday and tested it yesterday, I'm incredibly happy with the results, I'll get some pictures on here. It's made of 3/4" steel plate, so it has a huge mass to absorb heat too! Quote Link to comment Share on other sites More sharing options...
tomhw Posted August 15, 2012 Share Posted August 15, 2012 "In a properly managed fire the recently introduced fuel insulates the touyer and fire pot from the the burning fuel." ??????????? How's that again? I add fuel to to the top and edges of the fire, green coal becomes coke, which burns up as it settles into the firepot, releasing radiant energy to heat the metal that I place in the burning embers. Some of that radiant energy heats other things, including the firepot. The unburnt ash and clinker settles to the bottom, but not enough to insulate the firepot. The recently added fuel serves to keep some of that radiant energy off of me, but I don't think it is helping the firepot. Claying the bottom of the pan would keep some off the heat off the twyer, and certainly keep the cast iron pan from cracking. John, I use a poker with a flat tip about five inches long and about two inches wide, angled at about twenty degrees. I slide it down the side of the fire pot to make an opening for the introduction of fresh coal. Move the green coal into the pot from the sides, compressing the coke and moving it into the hot spot. The fire stays concentrated and clear. Pressing the green coal in from the sided also permits you to raise or lower the hot spot, and move it around in the fire pot for focusing the heat and blast. Quote Link to comment Share on other sites More sharing options...
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