Buzzkill

I have limited experience casting and have never tried cast iron. However, I do know that you need to be able to melt more material than your finished product will weigh. Typically there are risers, sprues, and/or runners which will contain some of the melted metal, so you need to compensate for those things. In addition most castings require some cleanup or machining which will also reduce the final weight. I have built a heat treating oven which uses 110v. I built it to pull slightly under 15 amps. Just to heat the interior of the oven up to 1950 degrees F takes about 3 hours. That's for a space much smaller than you would need, there's no big heat sink (crucible) to add to the time, and it's still a few hundred degrees below the temps you would need. The bottom line is you were right to be skeptical about that furnace being suitable for your desires. I know you're probably already tired of reading it, but what you want to do is extremely dangerous and is far from a beginner's project. If you're serious about casting you should start with easier metals and smaller projects to get some experience before diving into the deep end of the pool. Aluminum and brass casting are also dangerous, but less dangerous than cast iron. If your budget is $6,000 USD you should be able to get the proper PPE, but I would also highly recommend using a portion of that budget to take a casting class or get some other personal instruction from someone who has experience doing what you want to do. You're much more likely to get the results you want and avoid serious injury or death that way.

It looked stainless rather than plated to me due to the fine machining marks that would probably be covered, or at least not as defined, if it were plated. However, at least one of the wear surfaces appeared to have rust, so I'm reserving judgment. If it is non-magnetic it is almost certainly stainless. If it is magnetic it could still be either plated or stainless, depending on the alloy.

First off. The party size helium tank is fine. There is more than one size, but if it's comparable to a disposable refrigerant (freon) tank then it's a good size for a first propane forge. I used one for a while with a single 1/2" Frosty T burner and was able to forge weld in it. However, if you think you are frustrated with getting odd-shaped pieces placed properly to heat a specific section now, that will only be magnified with a gas forge. Small gas forges do quite well with straight or nearly straight pieces that need less than 12 inches heated at one time, but when you are dealing with a chamber opening which is typically between about 4 and 8 inches in the largest dimension, that does create some additional challenges for irregular stock shapes. Breezes also tend to be an issue for a lot of naturally aspirated burners. However, the NARBs I have built don't seem to be quite as sensitive to wind as the single port burners were. If by "shelf" you mean the floor then soft insulating firebrick is not a particularly good choice. Between the thermal shock of repeated heating and cooling and the mechanical abuse of dragging hot steel across the forge floor an IFB will not last long. If you use flux you could destroy it in a single forge welding session. You're better off with a castable refractory floor or even a split hard fire brick. High alumina kiln shelf is better yet. Regulators designed for gas grills only operate at a couple psi usually and are not adjustable. That's barely enough pressure to make some naturally aspirated burners function, and not enough for others. If you want to build it right then you want an adjustable regulator. If possible you want to get one that can go from 0 psi to at least 20 psi. It's not so much about the "dial" (I assume you mean gauge here) as it is about being able to change the pressure of the fuel going to your burner. That pressure will be a major factor in the temperature achieved inside the forge, and while we caution people not to fixate on specific numbers, you probably won't be able to achieve the temperatures you want using a regulator from a gas grill. You do not need welding skills to build a brick pile forge. Many people have built them with a few pieces of angle iron and some all-thread rods for the main components. Frosty has shown pictures several times of forges built that way at his local club and they clearly work well as they are built. The best advice I can probably give you is this: pick one plan known to function well and strictly follow that plan. Don't substitute or change anything unless/until you ask the designer or a knowledgeable person who has used that design if it will matter. Once you build and understand your gas forge you will be in a position to incorporate changes/improvements into your next one - and there will be a next one.

I hate to tell you this, but those burners appear to be substandard. I found some pics of those on ebay, and the flames shown in the pictures leave a lot to be desired. If those are indeed 1" burners and you used Wayne's plans, then a single one of those burners should be overkill for that size of forge if they were of good quality. Two of them in a forge that size is ridiculously overpowered. What I saw was extremely rich flames, which translates to lower temperatures and a LOT of wasted fuel. Then there's the risk from excessive carbon monoxide production. The good news is that if you followed Wayne's plans you should have a well constructed forge. Assuming the regulator and hose are propane rated you are good there as well. All you need is one (or two, depending on the size) well constructed burner and you are in good shape. If you have a few tools and some basic shop skills you can make your own burners inexpensively. Instructions for making some reliable efficient burners are here: https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/ As a bonus, you get to troubleshoot any problems you may have with the designer of the burner. I don't know if we can realistically help you modify the burners you have now cheaper than just buying the needed parts and building your own burners. We can help you get a hot forge, but not with those burners in their current condition.

Yes, it's basically an oversized 1/2" T burner. I started off attaching the same single port 1/2" T burner I had used previously to the plenum. However, once I attached it to the plenum I always had a significantly rich burn no matter how short I trimmed the mig tip. The standard 3/4" T setup with a .023 mig tip gave me a lean burn, so I bought a 3/4" schedule 80 pipe nipple and that seemed to give me what I was looking for.

I did modify the design a little. I used a .023 mig tip, but initially I couldn't induce enough air to get close to neutral flames. I ended up using a 1" by 3/4" T with the .023 mig tip and a schedule 80 3/4" pipe nipple between the T and the plenum. The inside diameter of 3/4" schedule 80 is between the ID of standard (schedule 40) 1/2" pipe and standard 3/4" pipe. For the burner face I used a piece of insulating firebrick (2300 degrees F rating) and drilled a lot of 1/8" holes in it using a piece of welding rod. Unfortunately I don't remember how many holes I drilled, and of course I failed to write that down. I used a piece of a computer case venting for a template to help me with hole placement. Those bricks are rather fragile, and I failed on my first attempt before I got it set in the plenum. I managed to partially melt the first IFB burner head I successfully installed. I am still using the second one I installed, but it is starting to show some signs of degradation. I now have to use higher pressure than I did originally to keep it from burning back in the plenum after a half hour or so of use. That's not a problem when I'm forge welding, but I do end up running hotter than needed for general forging. I can't turn it down enough for tempering. There's no problem using it to prepare for quenching though. Hope that helps.

Yes they will. I'm using an upward facing NARB fed by a 1/2" Frosty T design. It's installed in a flat floor with a curved shell overhead (D-shaped forge). There's plenty of swirl. It's only visible when the forge is fairly cold of course, but I get even heating in the forge and am able to forge weld high carbon steel no problem. I haven't tried mild steel in the forge, but I'm pretty sure I could do that as well.

I'd bet that the "second table" is actually where a piece of the hardened face broke loose. I would not pay top dollar for that anvil, but if the remaining steel face has good rebound and there are no buzzing sounds to indicate delamination when tapping on the face it could still have a lot of use left in it.

I probably would attempt to make a surface grinder attachment for my 2x72" belt grinder if I had that part hanging around. It wouldn't have the precision of commercial surface grinders, but it would be close enough for blade work IMO.

I suspect most of us on here have had the same thoughts. It's a bit of a trap though. After a while I think most of us have concluded that it's actually cheaper in the long run to purchase known new steel for things like blades. A lot of times steel we get for free ends up costing us more in the long run, especially in the time and fuel areas. For knives I've found that the cost of the steel is insignificant compared to the fuel, abrasives, pins, glues, etc. There is something to be said for practicing techniques to improve them of course, but practice is usually best done with the materials that the finished product will be made from. For instance if you wanted to enter an archery competition and you decided to practice with a 45 pound draw bow although your intention was to use a 60 pound draw weight in competition, you would get some benefit - but you'd get more benefit by practicing with the one you'd use in the end. In this case a successful pattern welded billet is a source of joy when starting out, no doubt about it. However, that joy is even greater if you can turn that billet into something you can sell or use and be proud of. All that to say I recommend practicing with materials you intend to use in finished products. It seems a little daunting at first, but forge welding short, straight, flat pieces of high carbon steel really isn't that difficult to accomplish. If all mating surfaces are clean and shiny, the right temperature is attained, oxidizing flames are avoided, and firm "dead blow" strikes are used, the success rate should be very high.

EDA, I'm curious about the changes you made. It also may be of some use to others in the future, so take a minute to share the info if you don't mind.

You can purchase a brand new cast steel anvil of the same weight, and possibly have it shipped to you, for less than $1000.

One thing to keep in mind with single port burners like the one you pictured is they are LOUD! When they are running the roar is similar to standing near a jet engine. Multi-port (ribbon) burners are much quieter. If noise is an issue you may want to factor that into your decision.

Neither option is particularly good for stress corrosion cracking caused by aqueous chloride solutions. Many things come into play, such as temperature, concentration of the chlorides in the solution, etc. We've had 316 SS trailers which have had corrosion holes bored all the way through them in less than a year of service transporting brine solutions. Those have had to be lined to continue the service. Duplex 2205 supposedly has more resistance to damage from chloride solutions, but we haven't had those in use long enough for me to know if there is a significant difference yet. 304 is used extensively for USP grade products, pharmaceuticals, kosher grade food products, milk hauling, etc. It is the standard for food grade products that are not significantly basic or acidic. In the context of this discussion, a spatula made from 304 would not be an issue if the surface was brought up to a fine finish and passivated.

He doesn't need forging temperatures. I believe this could be accomplished by simply drilling small holes in pipes and feeding those with a T burner head. I'm thinking the normal length mixing tube ending in a T with capped and drilled nipples perpendicular to the mixing tube. Of course getting the right number of holes in the pipes might take a bit of trial and error.

You can check the alignment of the jet with the mixing tube by hooking up a pressurized water source to the burner where you would normally hook up the propane. If the water stream shoots down the center or really close to it then that's probably not your issue. A plastic syringe and some tape might even suffice here. It's a bit harder to check for gas leaking where you screw the mig tip in. If you want to be sure it's not leaking you can solder the mig tip to that fitting. If your fuel stream is centered in the mixing tube, and all the other parts are as specified in the instructions, a fuel leak inside the T is about the only thing I can think of that would produce a rich burn with an undersized jet. The closer to sea level you are, the greater the concentration of oxygen in the air, so that should only work in your favor. I doubt the humidity plays a significant role in the performance of your burner unless it's to the point where water mist is actually being drawn in. It's fairly humid where I live a good amount of the time and I haven't noticed a significant change in flame behavior due to the relative humidity of the day. Don't worry too much about the flame blowing out at moderate to high pressure before the forge is hot. Once the forge interior surpasses the ignition temperature of the fuel/air mix you can turn the pressure up and it will not blow off the end of the burner. You should be able to use a .035 mig tip for the burner if everything is constructed correctly and you don't have extra fuel being drawn in with the air. Before you trim the tip it would be expected to run a little rich, but you should be able to trim it back a little at a time to get the desired result. Don't forget to ream the mig tip orifice with a torch tip cleaner after shortening the mig tip. I think Frosty was confusing you with another guy who had a lot of fittings and copper line hanging off his burners, but the principle is still the same regardless. The fuel stream needs to be as close to centered as we can reasonably get it, and we want it to stay that way in order to get good performance from the burner. If the jet can move even a little bit off center it can make tuning a nightmare.

I concur. Our food grade trailers are constructed from 304SS, while the chemical grade trailers are typically 316SS. Recently we've purchased a couple that are made from Duplex 2205 SS which are supposedly even more corrosion resistant. Time will tell.

If it's running rich with a .023 mig tip and the correct T then you have an air induction problem or a fuel leak in the T. The most likely scenario is that the fuel stream is not centered well in the mixing tube. We've also sometimes seen fuel leaks where the mig tip screws into the tapped fitting. When that happens additional fuel is pulled in with the air, resulting in a rich burn. You should not be running rich with a .023 mig tip in a properly constucted 3/4" Frosty T burner.

I recently made a few karambits and ended up using a 2 inch wheel on the belt grinder, slow speed, and a steady hand to sharpen them. To grind the bevels I used a 6 inch wheel. There is definitely a learning curve, and it is harder IMO to get a good flat bevel because you have to rotate the blade to try to keep the spot being ground in line with the belt travel as you grind. I'd recommend trying a mild steel blank first to get the technique down before moving to a blade you want to keep or sell.

This may not give you good steel for a knife. If the spring steel is 5160, or has close to the same carbon content, and you combine that with mild steel which may have around 20 points of carbon, with evenly distributed carbon migration you'd end up with something around 40 points of carbon - assuming you are using equal amounts of each starting material. You'll probably also lose a little carbon in the process of forge welding. The end result could be squarely in the medium carbon range, which will harden but is typically not considered good for edge retention. Since creating pattern welded billets is so labor and time intensive I assume you'd prefer to end up with something that will make a decent knife when you get done.

Glad you got it running! To me it looks like you still have some tweaks to do though. It appears as though the flame is canted a bit as it enters the forge. This could indicate either an alignment issue inside the burner or that the mixing tube is aimed so that the flame is impinging on one side of the burner port before it gets to the forge. You also appear to have multiple combustion envelopes in the flame. You can probably still get a hot forge, but it's not ideal. Mikey and Frosty are much better at analyzing flames, so hopefully they'll jump in and give their opinions.

There are a few possibilities. If it were me I'd start by trying to narrow down those possibilities. First off I'd want to know if the problem was in the supply line(s) or in the burner itself. To check for that you can swap the supply lines going to your two burners. Change nothing else. If the problem moves to the other burner then a big portion of the problem is in the supply line. If the problem remains with the original malfunctioning burner then we can focus on the burner(s). What you are describing is usually the result of either a restriction in the gas flow (supply line or in the burner) or poor alignment of the jet compared to the mixing tube. It's also possible that back pressure from the functioning burner is interfering with the performance of the other one. That can be determined by firing the burners one at a time to see if the problem persists. A likely culprit is debris in the gas line, or in the mig tip, that is impeding gas flow. A tiny piece of dirt, metal, teflon tape, etc. is all it takes. Another potential culprit is a burr at the end of the mig tip which is causing the gas to disperse as it exits rather than form a stream. A torch tip cleaner can be used to ensure the orifice is clear of burrs and debris.

Sure, you can keep them in the logarithmic casing - sold separately.

Unfortunately for me, that sounds quite similar to this: https://www.youtube.com/watch?v=Ac7G7xOG2Ag Although I suspect every word she's saying in that video is true and accurate, my understanding of that topic is so limited that she may as well be pulling the same stunt as in the video I linked to.

Another fun fact regarding illegal weapons in IL: Brass knuckles (or similar items constructed from any solid metal) are illegal to carry or even own. That goes so far as to include paperweights or jewelry shaped like brass knuckles.