Slysmith

Guys that is great advice. Like someone said earlier about making a forge/furnace, you can't have one thing do all jobs safely. I think I am going to use something utterly different for glass and something else for metals. Now, I suspect that clear polycarbonate should be all that one EVER needs for IR light. It really just can't get through a thick layer of plastic as I understand it. That is why greenhouses work. Well perhaps SOME gets through, but most IR should be stopped with just a bit of thick plastic. Frosty, I was going to get by with a welders mask I have, but I think I'm going to go with a full face shield instead. Safety is just too important to let something not be protected on the face. I mean really... skimp on safety equipment... that is just stupid. A face shield with a pair of IR/UV wrap arounds sounds like the right set up. Now, as a science teacher, I have a lot of aprons, but they are really only good for something like hot exploding test tubes. I can't imagine molten metal not just pushing right through it. As I mentioned, a friend has a jacket that is used by the guys with the flashlights that direct airplanes and THAT comes with a warning that it insulates enough that you wouldn't notice the jacket as being on fire. That would be for my chest area with SOME apron over the front. Then I'm thinking welders gloves and for shoes, I was thinking hiking boots (that have laces). Now someone said you cannot have exposed laces no matter what, so I was thinking of making some kind of dorky leather cover over the parts of the boots that have laces. Any opinion on that folks? Feel free to chime in on safety. I'm planning on melting over sand/dirt in the back yard. Nothing but Al ingots at first. Tomorrow I am off, but taking care of my son. I expect that I may get the chance to take pictures of what I have so far and possibly post pics. Then in a day or two get started with the furnace. Though it may be boring to all of you helping a noob get up to speed, I really appreciate the expert help folks!

Ok well Frosty, now that you have brought up eye protection.... I'm going to hope folks will chime in here. I clearly want to protect my eyes and I do not want to let dangerous radiation in. NOW, I am considering also working glass at some point and clearly would need some Didymium glasses with protection in other wavelengths. I do not want to skimp at all, but I also want exactly what I need. I was thinking of getting THESE lenses for both looking at the interior of the furnace when needed and if I ever did lampworking with borasilicate glass. I really want to get this right the first time. Mosaics Unlimited Didymium Safety Glasses - Fusing Stained Glass Supplies I have been looking for several hours over many days trying to educate myself on the eye damage issue. Many folks say that unless I'm going to try and use borax to try and clean up the metal, then I don't really need to worry about sodium flare... OK but there are many other issues as well such as getting just too much visible light in your eyes as well. My wife has crappy night vision and mine seems to be superior to at least hers. I really don't want to screw that up. Found a good article on the whole issue with the EM radiation thing HERE: Visible Light Hazards and the Glassworker

Char, so if I form my furnace with the mix and then line the center with just fireplace cement, then I'll be OK? I have seen quite a few "slumped" furnace images and I guess that was pearlite that was in contact with the fire. --thank you, I was considering mixing and making today. I'll keep the pearlite out of direct contact. What did you mean by back up insulation? I don't have access to any rockwool or fancy insulation. Hmm... so give Pieh Tool company a try. Thanks a lot. Does anyone know what happens to eyes that are overexposed to the EM radiation of a forge or furnace?

Bent, Let me ask this about forced draft. Your propane was about WHAT PSI coming out of the tank. If I read this when you say "forced draft" you are NOT just allowing a tiny hole to venturi in outside air, but you are actually forcing air into the mix WITH the propane and this is creating a hotter flame. Although this creates a temperature higher than anything I need, I am curious about this configuration. One NEEDS to force air into a propane burner and cannot expect a tiny hole to pull sufficient air from the outside? I am not interested in these extreme temperatures at all until I feel very comfortable with not only melting Al, but in pouring, greensand casting and eventually lost wax casting. When I was in college, I was around a fair bit of bronze casting, but did not have the class. My sculpture class was not quite at that level, so I didn't get to do my own casting, but I'm about as experienced as you can get without doing the casting. I wonder if you have any images of your fancier, higher temp, furnace and the setup you have used. I only thought a blower was really necessary for waste oil furnaces and when you used coal in a forge. Once I have a source of firebrick (they ARE about an hour away from me) I am interested in forging my own tools to handle my simple crucibles (steel pipe). St.John, I'm just trying to get comfortable with melting/casting and then at some point I'll even try some potassium chloride once I have a good mask and protective gear. Folks seem to mis-interpret my future desire to melt things like iron as something I'll be doing tomorrow. When you say "lead pot" don't you mean that small scoop that is iron or steel that is used to melt lead? You don't actually mean that you are melting aluminum IN a lead pot. Sorry if I am off on the terminology there. Anyway, thanks folks for adding info. The books that are the tried and true for metal casters is also very welcome. I do wish someone that is familiar with and has used and built the perlite / fireplace cement type refractory would chime in and offer opinions or personal pitfalls. I know those of you that melt iron poo-poo at the wimpy capacity of such a furnace, but really folks, I am just trying to melt aluminum as a path for greater things to come. Just cause I ask about a coupela, doesn't mean I'm gonna build one tomorrow... ------------------------------------------ Can anyone that truly knows what they are talking about offer advice on how I might avoid burning my eyeballs (via EM radiation). I know that folks that work glass use some form of ruby lenses, but is the danger the same from melting glass as it is for heated metals? What is the wavelength of light that is the problem for the eyes (is it infrared?) and how does one SEE clearly when pouring or looking at the metal? -please don't answer that one without really BEING an expert on the EM radiation hazards. I certainly am not.

So, use the brick that are used in a fireplace. Interestingly I have never heard that suggested in all the time I have spent lerking about thinking of melting metals and casting. Pipes for chimney flues... sure, but not the BRICK that are used in fireplaces.... Very smart. There is a brick company about an hour away and I did not think about just getting brick for a fireplace and not actual firebrick (I forget what firebrick are made of, does anyone recall what the elements are?) Oh and yes, the pipe I got and made the burner out of is in the ball park of what you mentioned. The pricey bit was the xxxx regulator to get the right pressure. I may really have to have something that allows me to move the furnace around and I can't see the wife letting me build a brick furnace in the back yard. BUT I might could use my in-laws place... they have a ton of land. Hmmmm... something to really consider. By the way, I have heard many folks talk about one form of refractory adsorbing heat and others reflecting heat. Can anyone comment on this? Clearly I'd much prefer to reflect heat and conserve energy. About Crucibles, once I step above using a steel pipe, I have the art teacher down the hall that will craft me all the crucibles I want.... That is if ordinary redware clay is up to the task? Is there a different clay from the ordinary pottery clay that would need to be used? I know the shapes are different, and walls pretty thick, but will ordinary clay work for aluminum ok? How about iron and steel one day? Ceramics pretty much withstand heat far above ordinary melting points right? (I'm not planning to melt tungsten). For tools I was probably going to just get by for now with my own custom crafted junk and then if I made a forge, I'd bend some metals and craft the fancy clamps etc. needed to actually grasp crucibles evenly. Moving up to ceramic crucibles would give me a reason to make a forge and craft some tools. Oh and Charlotte, I have a friend's coat that is used by the guys that direct airplanes in the cold and it warns that the coat can catch fire and you wouldn't' be aware of it. I figure that and welders gloves will work till I can fashion a heavy leather apron. I have an old welders mask but I guess I'll use plain glass so I can see. I have one question no one has mentioned about safety. I have heard that long term exposure to the infrared spectrum can be damaging to the eyes. Is that in fact the case and do any of you use anything that filters that part of the spectrum out? Thanks again folks for all the help.

Bloom furnace... Like to hear what a bloom furnace is. Yes, I'd love to hear what you friend has to say about all his techniques. What works, what doesn't. I'm not poor, but I can't really afford to create expensive fancy furnaces etc. Besides the making my own stuff out of "trash" is kind of fun too. so Sonotubes? Are those the yellow cardboard things I see at home depot for casting concrete INSIDE them. Never thought about using them the other way around. VERY smart. So can someone tell me really what a cupola is? Is it a furnace that HOLDS your iron inside and then you somehow TILT it to pour out the molten metal? When casting iron, how much of dealing with slag do you need to do? Wouldn't Iron oxide be a real problem unless you used something like the Bessimer process? I'm a long way from casting iron, but I'd love to hear about the process and what I want to work toward. I currently have a post at: http://www.iforgeiron.com/forum/f86/first-forge-seeking-criticism-12053/ If anyone wants to weigh in. Thanks.

Ok, Yes I did do poor job on the descriptions. My burner is easy to see if you google "Oliver upwind burner" (first hit). I drilled a #57 hole in a brass tube and it ejects gas to the side and into an 3/4 inch steel tube. I made a flare out of the same kind of pipe but it was an adapter that goes up to 1 inch. IF you see the 3 holes on the side, the third hole has the blue propane flame just visible and that means that I have burning propane for about 4 inches INSIDE the tube. That kind of bothered me even if steel is not the best conductor. For the er... tweer (tyuver? whatever the place for the burner) I have a steel pipe I will put inside my popcorn tin and set the burner inside of. This of course has no blower since the propane does the job. I have a single setting (unadjustable) 20 PSI adapter for the propane. Kind of regret not spending the extra for the ajustable. I wasn't planning to USE this as a forge, but perhaps if the mood struck me and I had not found firebrick. For a forge I planned to use a stainless steel sink with one side water and the other with a blower, refractory and grog lined sink (as seen in pop sci recently). THAT is still some time down the road (gotta find some kinda anvil if I'm gonna pound metal). HEY, is it possible to buy crumbled up grog (broken firebrick)? I could use a bag of that stuff. I just can not track down any freekin refractory other than the fireplace repair cement stuff from a hardware store (not Portland). I know there is a place about an hour away where I should be able to buy firebrick, so I'll go visit there this summer. I will use good refractory for a good furnace once I have gotten the low temp (relatively) of aluminum down pat. I certainly won't be melting brass in this thing. Maybe lead and aluminum (zinc if I get the breathing mask working), but not much higher than that. Oh and of course I'd never burn this inside. What kind of a nutjob (I'm sure there are many newbies) would do this inside unless it was in a warehouse. I'm planning to create a sand pit once I get started. I did not know the Potassium Chloride trick. I'll be certain I make my charcoal filter mask first to avoid the chlorine gas. BTW, where can one FIND activated charcoal? Oh and I know all to well about the gas laws.... Yeah too moist a casting would be terrifying. Anyway, I was just wondering if there was any glaring stupid errors before I got started. Is two inches enough insulation? I'll try to get some pictures up and running... Maybe even tonight. The lid will be a bit tricky it seems. Dodge, if you would look at the oliver upwind burner, and if you think the burning of the flame is taking place too deep in the burner, please give me an idea how I might slow the mixing down. I mean I guess I could try to cap the end so that less air is sucked in and perhaps form some kind of sleeve of steel to reduce the air from the sides. I made it pretty exactly as the design calls for, so I was surprised that I had the burning IN the tube and not at the flare. Thanks for the help. I really need to be prepared for the possibility of steam. I was not worrying about that, so I appreciate the warning Quench. Thanks guys for looking over my ideas. I'll try to show where I am in my progress as soon as possible.

I am trying to make my first furnace. I'm sorry if I mangle the proper words, so please correct me if I use terms improperly. I'm using a 5 gallon popcorn tin and giving it about a 2 inch refractory around the furnace of 5 to 1 Perlite to furnace cement. I cannot find fire clay locally, but since I am planning to melt only aluminum in this furnace and I'll start with a steel pipe crucible, I am imagining it is alright. I cannot find much aluminum locally, so I'm afraid I will have to deal with the massive amounts of dross from aluminum cans. I was able to melt a can with just some charcoal, and I estimate over half was dross. I made my own Oliver-upwind burner from steel tubing, but when I tested it, the flame seemed to be burning INSIDE the burner about 2 inches from the place the propane is injected. I thought the majority of burning was supposed to take place at the end of the pipe. End of the pipe got seriously hot in just a minute of burning. I'm going to have a steel pipe that holds the burner (whats that name of that? Tweer...?) and the flame AUGHT to coil around my crucible. The center open area will be formed as I squish my refractory around a sheet of duct taped aluminum sheeting. The bottom of the furnace will have a slight funnel dip if my plastic tub bottom holds its shape as I squish refractory around it. I'll have about a pinky sized hole in the bottom too and any spills aught to pour out the bottom in theory anyway. Is there any design flaw in what I am trying to do? Is 2 inches thick good enough? Am I in danger of slumping with these materials? Have any of you built a propane furnace out of these materials? I aught to be ready to mix a touch of water with the furnace cement soon and then I'll try to get the moisture out over several days. I saw somewhere that I want the furnace to dry SLOWLY? I understand that I don't want to fire it up after 48 hours drying time (except maybe in short bursts) but do I really WANT the refractory to dry slow with plastic wrapped around it? Is there a danger of cracking if the inside dries to fast or what? Anyway, for you folks that are more experienced than me, please offer some advice on where I might screw up or if I need to change anything. Thanks for your time.

If anyone wants to comment on those questions above, I'd welcome any answers. I'll be searching the forums of course in time, but I thought some of you might be able to show a link that you were familiar with.

I'm a 42 year high school science teacher. I'm buddies with the art teacher in our school, so I can likely get him to craft crucibles for us since he is also interested in casting in metal. I have a aluminum furnace I am crafting for now and eventually I want to get fireclay and craft something that can melt copper / bronze with no problem. In time I will probably try to create something like Lindsey's furnace that lifts from above and can melt iron / steel. I am curious about several items and I have not searched the forums yet. My curiosity includes: --What is the melting point of firebrick? fireclay? silica sand (or slumping point)? All this verses the metals one might be melting. Would hate to have a slumping furnace. --What compound HAS the highest melting point? --For those that use propane furnaces, do you find the propane to be expensive in the quantities you use it? My ultimate question here is IS A WASTE OIL furnace actually worth it in effort? Most waste oil gets recycled now in my area, so I don't know how I might easily obtain it. --Is a Coupela (sp?) actually worth it? Can you get clean metals, or does it just keep mixing in the old metals from before? --Lost wax or greensand? --And where the devil do you folks get nice clean ores at a decent price? I can try to recycle scrap sure... but unless it is iron, most metals I'd like to have are hard to find (Al and Cu). Anyway, I look forward to being a part of your community and learning from the pros since I am way down the row in experience.... as in I have no personal experience.