Daswulf Posted May 8, 2019 Share Posted May 8, 2019 10-12" single wall pipe is fine. No need for double wall pipe. Boilersand woodburners are closed systems and so more heat goes through the exhaust pipe. Also why they can use smaller diameter pipe. A forge stack draws a lot more ambient air and gets nowhere near as hot as a closed system. Also needs to be larger to get more draw. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted May 8, 2019 Author Share Posted May 8, 2019 Is single wall ok even where it passes through the wall or roof? By building regulations in the UK it would seem you'd need twin wall but maybe in practice its not worth worrying about? How hot/cold are we talking? Quote Link to comment Share on other sites More sharing options...
Daswulf Posted May 8, 2019 Share Posted May 8, 2019 The hottest area will be right at the opening. Can't really speak for the side draft openings but my hood doesn't get much over 200-275°f in normal use. It cools as it goes up. I can touch the galvanized pipe above my hood. And my hood is 2/3rds of a 55gal barrel. The original paint hasn't burned off in the 5 years of use. Mine goes up straight through my wooden and shingled roof. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 8, 2019 Share Posted May 8, 2019 Codes are generally written AND enforced by folks who have NO experience with forges and so are based on stuff they do have experience with. I can warm my hands on my 10" single wall forge flue at the same height above the forge that I can melt solder on my smaller diameter wood stove flue. As for what you are missing---it's the extremely large number of posts on this subject going back for years on this site! Including instructions on how to take two pieces of single wall flue that is shipped flat and snapped together for use to make a larger diameter flue at a reasonable cost. I use spiral seamed 10" ductwork as that was what I was able to source under a US dollar a foot. Of course My shop is metal and not anywhere near my house and falls under the "farm rules". Unfortunately if you have to meet local codes; you have to meet local codes! Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 12, 2019 Author Share Posted August 12, 2019 It's been a long while since my last update...... Progress on the forge has been slow, but I've been busy doing lots of other building projects etc. The workshop is all stained, and electrics installed which makes me very happy! I've only been using it for woodworking etc at the moment as I've been waiting for a chance to visit The Iron Dwarf and Geldon Forge (Kettering) to collect a new forge and side sucker hood. I finally made it this weekend. Next step is to sort out the flue. The hood is made for 12" pipe, so I need to order a few more bits. I also need to make some bent sheet metal brackets to be able to wall mount the hood with an air gap behind so as not to cause a fire risk. I'm still concerned about the neighbours (in terms of chimney height). I can't think of a way to make a retractable/removeable chimney so it looks like I'll have to get up a ladder and take the top section of flue off after every forging session! Fortunately/Unfortunately (depening how you look at it) thats not too often. I intend to add some additional beams crosswise between the purlins in the cabin, which I can use as hard points to mount a roof-support for the flue. The flue will only be fixed at that point and where it slots onto the forge. I attached a bonus picture of a bird made of cultlery which I thought some of you might enjoy! This beautiful piece was made for me by my best friend from work. He retired at Christmas (very happy for him, but I miss him every day..... and I have around 40 years to go before I can join him in retirement!). He doesn't weld, so some sections are soldered, and others are drilled, tapped and screwed. He files the heads off every screw and polishes them to be almost invisible. Its a work of art. I would love to hear any thoughts/advice on the flue/hood/forge plans. Quote Link to comment Share on other sites More sharing options...
Daswulf Posted August 12, 2019 Share Posted August 12, 2019 That's a beautiful shop. Hope you got some pointers from Iron Dwarf while you were there. Very cool bird sculpture! Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 12, 2019 Author Share Posted August 12, 2019 Thanks Das! Yes, I did get some pointers from both Iron Dwarf and Copper Elf. Both really friendly blokes. I'm hoping to get back up there ASAP for a tool making lesson with the Elf. Need to focus the cash on getting up and running at home again first. Quote Link to comment Share on other sites More sharing options...
Les L Posted August 12, 2019 Share Posted August 12, 2019 Jon, Very nice shop. I don't know how tall you have to make your chimney, but would it be possible to have it hinged so you could lay it on it's side, into a cradle to store it, when not in use. That would keep you off the ladder and eliminate a possible fall. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 12, 2019 Author Share Posted August 12, 2019 Good idea thanks Les. I'll have a think about whether thats possible. Quick update- balanced the forge hood in place to get an idea of where the flue will end up. I also bent up a very quick tong rack. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 20, 2019 Author Share Posted August 20, 2019 Picked up a new vice. It needs some work as its pretty rusty and almost seized. I'll get it cleaned up and back into service. Does anyone know if the jaws look to be original? I've havent seen a blacksmithing vice with removeable jaw plates like that before. Doesn't seem like a great feature for a heavy duty vice, and the bolts holding the jaws in are loose so the threads probably need recutting. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 21, 2019 Share Posted August 21, 2019 You might want to put a reflective shield between the flue and wall with an air gap between both. Are you familiar with cement backer board, used as a wall board to hang tile or back wood stoves? There are spacers made from the same material you can buy in packages, you just drive a screw through the backer board and a spacer to provide 1/2" dead air space. Cement backer board should be all the heat shield you need, even if you get crazy with the fire. Or, if you have a little stainless steel sheet you salvaged, scrounged, etc. mounting it with a space between the flue, SS and wall works really well. I used a printer's tin heat shield in a log cabin and with the temperature so warm we were opening the door there was ice on the logs behind the tin. Bear in mind those work in Alaska, USA I have NO idea what's legal in Essex, UK. I highly recommend you ask a professional in the business. I doubt any, here or there would like the thought of a telescoping or hinged stove pipe but the final say would be your insurance agent. Would you like to bet a couple pennies on his/er answer? Yes, I have a leg vise with replaceable jaws like your's has. Mine are seized so tight I don't know how I'd bet the screws out if I had to. If you can remove the screws and chase the threads out nice and clean. Buy new counter sunk screws that do NOT reach the bottom of the tapped holes. Install them with a dab of "LockTite" thread locking compound on them so they don't work loose again. However if the do start to loosen up take care of the issue before the threads are damaged. You won't be sorry you did, it's a pain chasing old damaged threads, better to avoid it with a little diligence. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 21, 2019 Author Share Posted August 21, 2019 Thanks for the advice as always frosty. I think my telescoping/hinged flue idea was just too whacky. I'll have to see how it looks but I think I'll just have to get up a ladder to throw the top section on when I want to forge. No big deal. I've mounted the hood now with a 200mm air gap to the wall. I will look for some shielding also. (The bench in the photo will be moving away.) As for the leg vice, glad to hear others have removeabke jaws and its not a problem. I took it all apart last night and the jaws are almost definitely original from what I can tell. I'll clean it all up and get it nice then post photos. Quote Link to comment Share on other sites More sharing options...
Neal the smith Posted August 21, 2019 Share Posted August 21, 2019 Hi Jon. I’ve just seen where you are based. I’m just round the corner on the Benfleet side of Basildon. We should meet up and beat some metal together. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 21, 2019 Author Share Posted August 21, 2019 That would be great Neal! Lets catch up via. PM. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 22, 2019 Author Share Posted August 22, 2019 I've finished making up a flue wall support collar. This is the last piece I needed so I now have everything to install my new flue. Unfortunately.... I just need a clear day to do the job and unfortunately I can't see that happenening for at least another week! The suspense is killing me. I can't wait to be able to actually forge again. In the mean time, I've been working on the new vice. It took a bit of effort over a few days to get the thing to pieces as the bolt was badly siezed. I've been gently wire brushing the surface and is coming up beautiful. Should have it back together again and working perfectly soon. If anyone is interested.... from what I can tell, the removeable jaws plates ARE an original feature. I cant see any evidence of modification, cutting or grinding. Perhaps that means this wasnt originally a blacksmith vice and might have been intended for another trade? Either way I'll get it fixed up. Someone suggested I could, in future, make other plates to fit in like a "Step Vise" for specific jobs. Thats an interesting idea. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 22, 2019 Share Posted August 22, 2019 Could be a new feature to make it patentable? When you said the bolt was badly seized did you mean the screw and screwbox or the pivot bolt down at the lower end of the moving arm of the vise? I've replaced and redrilled several pivot bolts, going a step up when the hole was badly worn; or one time I heat shrunk and bradded in a plug and redrilled the hole in the moving arm to get the jaws to align. (As I'm cheap I tend to pick up vises that need repairs that are simple to me. I draw the line at worn out or damaged screw and screwboxes though!) Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted August 23, 2019 Author Share Posted August 23, 2019 I meant the pivot bolt but it came free after a bit of effort. The scree and box is perfect. The only issue is the scewed in jaw plates which I cant decide what to do with... Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted September 2, 2019 Author Share Posted September 2, 2019 (edited) Finally finished installing my forge! Thanks again to The Iron Dwarf for the fantastic forge and hood. For anyone reading this in the future and considering doing anything similar..... (for what its worth, this was just what I deemed to be cheapest/easiest for me): The roof of the cabin is 12mm thick wood, with 50mm foam insulation and felt shingle tiles. The total cost of a 12" (300mm) flue (pipe, supports, flashing and rain cap) was approx. £400. To keep costs down, I decided to buy only the 12" pipe and flashing (£210 total) and make the rest from scrap. The wall support was made from a sheet of scrap steel and is way over the top (missing some bolts in the pictures but will be rectified). This is necessary, however, because the flashing provides no support. I've kept a 50mm air gap between the flue and any "combustible materials". This is not strictly to UK building regulations, as the flue would be required to be double wall and this is only single wall. However, I was assured that the flue pipe wouldn't get hot in the same way as a log burner would, and after a few hours forging I can confirm this to be true. The pipe is quite warm to touch but you can comfortably hold your hands against it without discomfort. As such I'm not concerned about safety, but I don't know what this means in terms of insurance etc. The building is many meters away from any other structures so no risk there. I can imagine a situation in future where the cabin burns down from some unrelated electrical fire, and the insurance company somehow worm their way out of it due to my flue clearance!!!!......... In the photo of the cabin below you can see the height of the flue- just over 1m above the highest point of the building. I want to keep my neighbours happy, so I remove this each time I forge in order to keep the chimney from being an eye-sore. The remaining stub by little chimney isn't likely to bother anyone. Unfortunately that means walking onto the roof before and after I forge every time! If I suddenly stop posting updates on IFI, I've probably fallen off and broken my neck. Nothing else I can do, unfortunately. I have a carbon monoxide detector in the cabin, and with the double doors open I had no issues with smoke or CO. The new hood draws beautifully. This officially means I can finally forge again at home! I only had a few hours this weekend but I managed to draw out and round off the reins on a pair of tongs which is a good start. The forge works beautifully, although I'm getting some air leakage out of the intake on my forge blower (essentially blowing back out of the fan the wrong way) which I assume is due to the resistance in the long hose. Planning to cut the hose shorter and see if this helps. The change from charcoal to coke is a dream- it seems so much easier. I think this is in large part due to the coke being smaller- its easier to rake around and fire management is generally so much easier. No more frustrations with the fire itself, I was able to work on two pieces of stock simultaneously, one in the anvil and one in the fire almost all the time. Edited September 2, 2019 by Mod30 Change the size of the font's Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted September 4, 2019 Author Share Posted September 4, 2019 Quick evening session tonight- just a couple of hours, but the first time I've ever been able to do so thanks to the dedicated indoor workshop. Everything is set up ready to go and it doesnt bother the neighbours. It was brilliant. I'm planning to forge a hammer rack using mortise and tenon joints for assembly. Perhaps a bit over ambitious but it will be a good way to learn. To start with, I need a square punch, so thats what I made tonight. The steel is EN19 which I believe is similar to 1040. It turned out well, although its not perfectly square so I'll have to cheat with a grinder to finish it off. I took advice from one of JPL's comments somewhere here and went for 9" in length. I heat treated using a residual heat method. Do people sometimes use a punch as a drift in the same tool? Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted September 9, 2019 Author Share Posted September 9, 2019 I tried to tidy up my square punch with a grinder this weekend, and discovered..... a big crack. Doh. I worked away at it a bit to see if it was just at the surface, but it goes deep enough to be problematic. Obviously the punch is scrap, then. I performed the heat treatment wrong, in hindsight. I forgot about "critical heat" when quenching, and I believe it might have been way too hot during the quench. Is this the likely cause of such a crack? If not the above, then any suggestions what could have caused this? (EN19 steel, aka 4140) Should I have used oil for the quench? Or perhaps the core wasn't hot enough when forging? Or a bad job when tempering? Also- any tips for NOT burning steel....!? Quote Link to comment Share on other sites More sharing options...
pnut Posted September 9, 2019 Share Posted September 9, 2019 Cut it off and turn it into a rodded punch. Pnut Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 9, 2019 Share Posted September 9, 2019 Tips on not burning your steel. Learn your forge! You will get till you know about how long/how much air it takes to heat a piece to forging temp===also if you are using an electric blower---get a hand crank one to use till you get good at forging. Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted September 9, 2019 Author Share Posted September 9, 2019 Hah- thanks Thomas. I'm definitely still getting used to the new forge (and new fuel!). Its much easier in many ways..... but perhaps a little too easy to overheat. As you say, I'm currently using an electric blower. Hand crank blowers- aren't these incredibly expensive everywhere? I've been looking on eBay in the UK and they seem very difficult to find and very expensive. Unless I'm looking in the wrong places? Quote Link to comment Share on other sites More sharing options...
pnut Posted September 9, 2019 Share Posted September 9, 2019 (edited) Did the crack happen at the spot where the quenchant ended and the air began when you were hardening it? It being a hot punch/drift it doesn't need to be really hard anyway. Pnut Edited September 9, 2019 by pnut Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted September 9, 2019 Author Share Posted September 9, 2019 Certainly in that region yes (I was agitating it). Quote Link to comment Share on other sites More sharing options...
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