dragonorb13

I actually moved a couple years ago, I'm in Alabama, in a little spit of nothing just outside of Dadeville. If I were still in NM, it'd be a little easier, I knew a few fireplace shops there that sold high temp fire bricks and such, and could probably get castable refractory. Frosty. Thank you for that explicit differentiation. I did *not* know there was a difference, and I'm very happy my tired brain remembered to pop over here and check this thread while I was looking through stuff. Water setting castable refractory. Not that I'm going to pay this guy for it, but is this the *kind* of thing you're refering to? (I'm sure I can find it somewhere else, but 94% alumina seems like a good "high alumina") while I look for other things, your suggestion of kastolite among them. Links to commercial sites is a violation of the TOS.

Exactly as you say, I didn't want to have to spend a couple hundred dollars just to get one bag of refractory cement. Le sigh.

So, I'm trying to find a recipe to make some homemade refractory cement to replace my old refractory plaster stuff, and I've found a few, all of which involve Portland Cement as their base. But I've also found a few places that unequivocally say not to use Portland Cement, because it will spald. But none of these explain if this is universally true, of if it's only true of straight portland cement. So, I was hoping I might be able to find some people who use a similar recipe to what I've found, who can tell me how hot you can get it before you run in to issues. Mostly I just want to cast aluminum and forge iron, but my roommate and I had been talking about trying to cast copper and sliver jewelry, as well. Formula is as follows: 1.5 parts Portland cement + 2 parts Perlite + 2 parts silica sand + 2 parts fire clay Thanks, guys!

I meant that the forced air introduction was optional, assuming of course that you have sufficient air being introduced naturally. For clarification, are you saying that the air inlet itself isn't optional, as in I'll need SOMETHING in the line to mix in air, or just that air itself isn't optional? I want to be certain I've got a proper understanding of the system before I start, so I don't do something wrong and, best case, have to start from scratch or, worst case, blow something up. My landlord doesn't mind a forge, but I'm pretty sure he wont' appreciate the "new, glamorous crater" in the back yard.

Alright, questions, then: 1) Choke would go on the burner itself, at the start right after the fuel supply goes into the burner? 2) The regulater and hose are parts of the fuel assembly? 3) Is the 'shaft pipe' the part between the fuel assembly/choke and the expansion chamber? 4) If 3 is yes, would the bell reducer be the attachment point between the 'shaft pipe' and the expansion chamber? 5) What, precisely, do you mean by 'pipe with orifice? Do you mean the pipe I'm using as my forge chamber needs entry into it for the burners, or is there something special with the pipes I use as my burner?

So, I just dropped way more on the shell, the insulation, etc, than I'd wanted to for my first forge... since my funds are a a little... let's say lacking, I was wanting to possibly build my own burners for it. The problem is that, while I've found several HUNDRED pictures here and just on google of the end product, a several hour dive into google didn't provide me a list of parts or an explination as to how they work. So, I'm going to list what I could figure out from pics and videos, and if I'm missing anything, I'd like it if someone stopped me from blowing myself up. 1) fuel assembly (copper tubing, with with pressure regulators, shut off valves, etc) - supplies fuel to burner 2) assembly attachment point - attaches fuel assembly to (yeah, i know, seems obvious, but if someone else uses this in the future, i want the list as complete as possible) 3) supply tube - moves the fuel away from the fuel assembly, so it doesn't overheat and kersplode and kill me 4) expansion chamber - allows fuel and air to mix, if air is supplied... not sure, if no air is supplied 5) air inlet (optional, seemingly) - I've only actually seen a few models that include this, but they supply constant air flow to increase temp of fuel burn, or to optimize it depending on the explination, usually with a fan (one guy actually used a hair dryer)... attaches to the expansion chamber. I haven't seen anything that has specified you need any 'special hardware', as in the burners on my stove look different, but i assume that's for dispersion of heat and fuel. Most of them I've seen just use some kind of threaded steel piping, though a few have been welded together. Am I missing anything? Am I wrong about any of the parts? I'll gladly edit and update (with notes) anything I've screwed up, becuase I'll probabably use it as reference material on future, larger forges. Thanks!

Upon further investigation, the only issue with the graphite crucibles is that, while they are cheap on their own... getting one with a lid, however, is... less cheap. And I'm willing to go through the effort of redoing the crucible every time :D

Awesome! Thanks, both of you! And everyone else that's given me information thus far.

As a side note, Thomas, no, the 13 is NOT age, or even age I started using the account name. It's a reference to something out of a DnD manual. I'm 28, so no need to worry about that. Also, any iron, wrought or otherwise, you're willing to spare next time you're in the area, I'm more than willing to take off your hands. (Just read through the thread a little more in depth, grabbing names from the various posts to look up)

Looking at the pictures and designs, this looks fairly close to the model I was planing to use. The only difference I see is that the one I was originally planning to use had the 'chimney' somewhat more closed off (not completely, but fairly close) to retain the heat better, and used two sets of bellows to force-feed oxygen. I say it this way, because the half dozen pictures and the couple of explinations of the theory I found readily all indicated the chimney to be fairly open to allow the (char)coal or other fuels to draw in oxygen by means of convection... air in forge gets hot, expands, goes up, cools, contracts, draws in cooler air from the bottom, lather, rinse, repeat. I am a complete amature at this, only having produces a couple of low quality items, so please feel free to correct me if my understanding is flawed, I'm always willing to learn. Infact, I'm more than willing to absorb all knowledge your'e willing to hand out. I haven't had a chance to read the previous articles and authors you directed me to (colledge > hobby, sadly), but I have a 5 day weekend starting tomorrow, so after the programming and troubleshooting homework is completed, those are at the top of the list.

Actually, either the Norse or some group the Norse were trading with (or raiding occasionally) were producing crucible steel around 800-100 AD (http://en.wikipedia.org/wiki/Ulfberht). And while I'm not looking to reproduce the blades, necessarily, I do want to reproduce the system for making the steel, though I'm more than happy to use somewhat more modern materials in constructing the stages leading to it. I'm also willing, until I can get my own furnace system operational (yes, fire hazard IS my primary concern with this particular issue... I have no way to contain temps in the range of 3K at the moment), someone else more modern furnace. If you wouldn't mind directing me to information on how to do it, I'm always open to new ideas. Especially since I haven't started this process yet. I've found plenty of things on "what" it is, but I tend to understand something better when I know how it works than just what the process does.

Actually, the plan was to use a semi-sealed container (the lid fits down fairly firmly, but isn't actually sealed on so that gasses get out, but limits how much gets in) for the melting process. The slag migrates down, with the addition of silicons as flux. I was originally hoping for some kind of ceramics, but the high temp ceramics require industrial equipment. I'd planned a narrow cylinder, so that it comes out similar to round bar stock, and just lop the slag end off. I was planning it this way so as to avoid the necessity of worrying about 1) casting it (as pointed out, exceedingly dangerous) or gasses permeating the metal (annoying). I know it will take longer to heat, due to the need to let everything settle, but the advantage being that it can simply leave it in the oven until it cools completely, negating a lot of the danger to body. The reason for wanting something at least semi-disposable is to allow it to be destroyed and (preferably) reused, such as fire-brick, which I know is made with chunks of firebrick (I wonder where the first firebrick came from, if firebrick is made from firebrick fragments o.o). Mr. Newman, would you happen to know the composition, in roughish proportions, of the firebrick they used to line the arc furnace? (not expecting it, just inquiring) Also, what does teeming mean, in this context? I doubt you mean in the same why you would with, say, trout in a river. And thanks for the great resources!

Well, Thomas, quite frankly, you just hit the nail on the head... me and a friend of mine want to experiment with making crucible steel. Predominately, yes, I will be adding impurities (carbon), but I also intend to remove other stuff. I don't need to handle it in the sense of container transference. Once it's heated to temp long enough to melt the iron/steel, i intend to let it cool and then remove the settled slag from the cooled metal. As to the use I intent to put this to, bladess. Knives, axes, swords, yatta yatta. Weaponry of all sorts that need an edge. Don't really think a mace needs crucible steel. Which neck of the desert are you in, Thomas?

Well, I'm in the US. Specifically, New Mexico. As a little bit of a quantifier, if I can reuse the material, price isn't relavant to the discussion. It's only relevant if I can't reuse it. I'm more than willing to invest in something that I can use over and over. As to safety, I'm in a desert with few trees and fewer scrub plants in the area. Starting a wild fire in this particular spot (yeah, I know Arizona and NM have have had a few fire issues the last couple years, just not where I'm at) is extrodinarilly unlikely. Especially since I'll be using someone else's oven. As to the safety of the material, good point... non-toxic IS kind of a must in this situation. I'd be more than happy with ceramics, but the only ceramics I know how to make are the kind you make by firing clay, and i KNOW that won't stand up. EDIT: When I say "someone else's oven" I mean that they have all the relevant permits, etc, and safety equipment for malfunction in place.

I'm trying to liquify some steel/iron to flux out the crap in it. The problem, naturally, is that high-temp ceramics are bloody expensive, and I could only find three places that wouldn't charge my entire left leg for a specified shape, interior size, and thermal survivability... and they still wanted knee down. To top it off, the material wasn't in any way disposable or reusable. What I need is a material that is either fairly cheap to produce (like Plaster of Paris cheap) or I can break down with relative ease to reuse (as in smash it to dust, reconstitute it with water, shape, let it dry kind of ease of reuse). It needs to be able to survive temps of 3500F or better (wiggle room, I know must steels and iron cap out around 2750 degrees), though +/- 250F is acceptable, if nobody can give me my target. I would LIKE for it to be easy to destroy (like smash it with a 3 pound hand sledge sort of easy to destroy). I was thinking of just using firebrick, but I have no idea of how to make it, and the 'tutorials' I could find were... lacking in precision. I have the will, the ingenuity and the sheer lack of anything better to do to get it done, I just need some ideas. Thanks!

Personally, I just use vegetable oil... the kind you use for cooking. It works great for my high-carbon machete. The only draw-back is that you have to renew the finish about every week to two weeks. If you're doing heavy use of the blade, such as (in my case) actually clearing weeds with it as part of your job or something, you'll need to renew every two days or so. Motor oil won't last any longer than a week or two, assuming defensive usage, given that it has similar viscousity to veggy oil. Don't know about floor wax, but it might last a little longer, since it's a solid protectant. Then again, since it's fairly soft, it might wear down faster. As to the linseed oil, I doubt it will last any longer than cheap floor wax or veggy oil for someone "taking it out side". Sure, if you're using it for a display item, the stand oil is great, but I'm assuming he's putting to at least a light workout.