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I Forge Iron

Buzzkill

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Everything posted by Buzzkill

  1. I don't run 2 burners, so I don't have a direct comparison. However, when using a single burner with a 3/4" mixing tube I get 10+ hours from a BBQ size propane tank for general forging. My forge is a little smaller than yours though. When forge welding that time drops significantly. Generally speaking, a .023 mig tip would be appropriate for a 1/2" mixing tube. For a 3/4" mixing tube I'd be running .030 or .035, depending on a few different factors. All that to say you're probably in the ballpark for a 2 burner setup in my opinion. If someone else who is running about the same size forge with 2 burners chimes in you should definitely give their opinion more weight.
  2. It also looks like someone used a lathe to cut out the threads, but then left an abrupt lip on the air intake. If the burner has the performance you're looking for it's probably not a big deal, but "features" like that can cause extra turbulence which may negatively impact the functionality of the burner and/or the air to fuel ratio at different pressures.
  3. If your build is based on the video you linked to you should end up with a well-built forge. The only issue I had is the consistency of the castable refractory. To me it seemed there was too much water, and that could make for a weaker lining. Whenever I've used Kastolite 30, it is not able to be poured like that when mixed the way I understand is correct. However, it's a small item and we aren't applying a lot of structural force to the lining, so it will probably be ok. I've never used any type of glue to hold the blanket to the shell either, so I have no idea if there's any real benefit. Other than that, it appears to be a well thought out, designed, and constructed forge. I like the removable floor and the sliding stock support - although that ideally would have a handle of some kind to help slide it in and out. Those tend to get hotter than is comfortable to grab with a bare hand while the forge is in use. When you say "heat treating stainless steels" what exactly do you mean? If you are referring to ramping up and reaching prescribed quench temperatures it could/should work well for that. If you want to be able to temper as well you will probably find it difficult or impossible to maintain temperatures in the 200 to 400 degrees C range with the same forge/burner combination you used for achieving quench temperature. You may be able to run a significantly smaller burner and use the same forge body, but for me electric is the way to go for tempering. Other than that I'll just mention that most of us started out with a forge larger than needed because of the mindset of "better to have it and not need it than to need it and not have it." However, for many of us, that forge sits gathering dust or has been tossed out. Now when I think about rebuilding/modifying my forge it's always along the line of trying to figure out the shape with the lowest volume that will still allow me to do what I want to do. If you are going to be making stainless blades 15 inches long you may need that extra length, but it does come at the cost of significant extra fuel consumption. What you are suggesting isn't crazy big. It's just a bit bigger than would be recommended for forging. When you throw in the heat treating aspect you have to decide whether it's worth the cost to have the extra length or to stand there and pump the blade back and forth through the forge to get an even heat before quenching.
  4. It's kind of tough for us to answer the question of how to mount the burner without being able to see much of how/where your latest forge is placed. Without trying to sound too sarcastic, you *do* have a forge. If you have some flat steel you can always heat it up and bend it into the shape you want to hold your burners where you want. If you've progressed enough to punch a couple holes and set a couple rivets it shouldn't be horribly challenging for you. There are many ways to hold them in place without welding. One easy solution is to use hose clamps to fasten the burners to whatever you built to support them. Some people have used conduit clamps. Baling wire would even work. Your imagination is the limiting factor. All you have to accomplish is reliably holding them in position.
  5. Thanks for all the replies. I have some of the gel stuff, but it can get a little messy sometimes (or I can get messy with it). A dry spray coating seems like a better option to me. I do far more stick welding than MIG, so I don't have much experience in that area.
  6. I have a question for some of you experienced welders out there. I was told that hairspray does a good job at keeping MIG splatter from sticking in the nozzle or to stock. Obviously you'd have to wait for it to dry, but I was curious if anyone else had ever heard this or if I need to get the other leg pulled to even them out.
  7. Yep, the best people are leaving, retiring, or dying off. A few years ago when I had tendonitis I was with my wife for an appointment and she mentioned my tennis elbow. Without missing a beat the doctor asked if I wanted a shot for it. It was not my appointment, nor was I even officially a patient of his, but I had a problem and he had a treatment. I'm guessing he may have gotten some blowback if the bean counters knew he had done that, but he made an immediate impression on me and I knew after that I would see him for anything from the shoulder to the fingertips (his specialty). Sadly, he passed away a few years ago. The other doctors in the same practice are good, but they are not him. I don't think a single one of them would treat a person before knowing they could bill the treatment. He did it without hesitation.
  8. The easiest solution may be just a hole in the center of your bolt head to allow a small amount of fuel air mixture through.
  9. Love the flame shape. That looks awesome! I haven't fired up my forge much in the past few months, but now I'm gonna have to resist going into tinker mode when I get back out there.
  10. I'm fairly sure that if I tried to use the one I got on a surface grinder the stock would slowly drift on the chuck while in contact with the grinding wheel. I can slide the piece of angle stock I mentioned before along the length of the chuck with a little effort. I'll be contacting the manufacturer, but if I have to pay much for shipping to send it back to them there's a good chance I'll take it apart instead.
  11. Sounds like it's either a bad design or a quality control issue. I'm tempted to take it apart and see if there's any way to adjust the magnets that move inside. It could be that the moving part is off by a quarter inch or something similar. Sorry, I don't know the terms for the different parts of that tool. I can feel some pull about 1/8" of a turn from the off position, and the hex key does rotate pretty much a full 180 degrees from the "off" to the "on" position.
  12. I recently purchased a relatively cheap Chinese magnetic chuck. It's 6" x18" and weighs nearly 50 pounds. In the "off" position there is no attraction to magnetic steel at all- as would be expected. In the "on" position I can fairly easily remove a piece of angle iron that is about 6 inches long, 1/8" thick with 2" sides. That doesn't seem right to me. I figured I would be able to lift the entire chuck into the air by pulling on the piece of steel with the chuck in the "on" position. However, I have no prior experience with these, so I don't know if I have unrealistic expectations or a substandard chuck. Any thoughts from those of you who have experience with these?
  13. Same as drawing out any other piece of stock. Make sure it's plenty hot. Use a radius edge of your anvil with half on/half off hammer blows. Alternatively use the horn of your anvil instead of an edge of the table. You're just trying to maximize the force on the minimal amount of surface area - and have that force directed so it lengthens rather than widens your stock. The only real difference with damascus billets is the potential for failure at the welding surfaces. However, if you did a good job setting your welds and you keep your steel hot it should be pretty much the same as mono-steel.
  14. This confuses me. For both the rigidized fiber blanket and the refractories I've used, they actually turn completely white when they are properly fired. With use the forge interior will take on some darker colors from the steel and impurities, but not as a consequence of proper firing sequence in my experience. You're switching gears here. It's best to pick a design that is known to work and stick with the routine developed by people who have successfully used the design. I don't know if you're talking about insulating fire brick or hard fire brick. They are completely different animals as far as their use in a forge goes. When did vermiculite enter the conversation? If you keep bouncing around with all these ideas you'll probably end up confusing yourself and spending far more money than you will if you zero in on something and stick with it. The forge pictured by Frosty is a proven excellent little forge which is very reasonable to build, uses no blanket, and does not require any welding or special tools. If you want to go the brick route it's a good choice.
  15. I suspect this is the source of your problems. You stated you have a propane tank size forge. There is no circumstance I can think of that would require quarts of rigidizer. Normally we suggest people add food coloring to the rigidizer so you can see how far it has penetrated into the blanket. It does not need to be drenched and dripping. If I understand you correctly, the blanket layer pulls away from the Kastolite and leaves a gap between the two, which is what concerns you. However, if you follow the steps listed on here and you are applying the materials correctly this should not happen. Install a layer of blanket. Apply rigidizer. Completely dry that layer of blanket with direct flame. Install the second layer of blanket. Apply rigidizer. Completely dry that layer. Now spritz the surface of that blanket with water before you apply the Kastolite directly to it. Enclose the whole thing in a plastic bag or tub with some water and or/wet towels for a few days. Let it air dry for a day or two. If you have an incandescent bulb drop cord with a 40 or 60 watt bulb you can put that inside for a day or so to help drive off excess moisture. Then you need to finish off by running flames in the chamber briefly at first. If you see steam escaping stop immediately. Gradually you should be able to fire the burners longer and longer until you are able to get up to a glowing forge interior. I don't apply plistex/matrikote, etc. until after I have been able to fully fire the Kastolite, but I don't know what other people do. You're assuming the insulation is the problem - and you may be correct. It's also possible that your burner(s) is not up to the task or that you have wide open ends on your forge or that you are not running high enough pressure to bring your burners to their full potential. The only times I have used perlite in a build have been under a layer of insulating blanket. I wanted a flat floor in a cylinder shaped forge, so perlite let me easily transition from the curvature of the shell to flat, but I still used the blanket over the top of it, and then Kastolite on top of that. If your forge and burner are functioning properly, I'm fairly sure that a thin layer of Kastolite will not insulate well enough to avoid melting perlite directly behind it. If they are mixed together you will just end up with a weak porous layer. Kastolite already contains little spheres designed to help with its insulating properties. You don't need to add anything to it. The dangers of ceramic wool fiber are real, but they can be eliminated for all practical purposes by using the correct techniques. There is another option which reportedly does not have the biopersistence and respiratory consequences of kaowool. It is called Superwool. I have used it and have noticed no significant difference in functionality compared to kaowool, but I still rigidize it and seal it with Kastolite even though the manufacturer claims it does not have the harmful effects of other blankets.
  16. I built something similar years ago. I agree with Latticino. You'll probably want something with a little more accuracy on the eye end. I used a rod end bearing for the eye portion and of course the appropriate size round stock to slide through it. There's pretty much zero play that way and your file strokes stay very stable. For small to medium blades this can work well. For large blades you can run into the limits that the eye will allow you to swivel. It looks like you're set up about right so that the file will be centered on the cutting portion of the blade rather than the center of the blank. That is the right way to do it. The next crucial thing is to ensure that the blade remains supported and stable while you're working on it - and that when you flip it everything is complementary to the first side. There are a couple good options depending on the handle style being used. For full tang knives one of the easiest ways to hold the blank down is to run a screw through one of your pin holes. Two is better. You also want a stop at the spine so you can ensure the same precise bevel angle when you flip the blank. This can be a screw, a nail. a board backstop, etc. as long as it doesn't interfere with the file while in use. You should mark the center of your work area on the board so that you can make sure your beveled area is centered when you flip it. You can just put a small mark on the center point of the spine that lines up with that and then when you flip it line the marks up again. As Latticino said, you may need to support the tip or you can get a bit of a spring action if you bear down on the file, and that can throw off the edge geometry near the tip.
  17. To me it seems like you're trying to force an analog control on a digital tool. I've built an electric furnace/heat treat oven with a PID controller. For most of these setups the relay is either fully on or off, and the time spent on or off determines the temperature rather than trying to use something that holds valves partially open or uses variable current. I'm not suggesting it's impossible, but it does seem like you're making it far more complicated than it needs to be in my opinion. If you have your Frosty T burner(s) properly tuned, then you never have to adjust the air. All you have to do is change the gas pressure and it will pull in the right amount of air. A bypass setup with the lowest functional pressure for the burner and then a solenoid controlled main line set for somewhere near the max pressure you plan to use is all you need. A PID controller with an autotune feature will figure out the rest of it. Of course if you change the configuration of your forge or use significantly larger or smaller openings at the front or rear you may have to recalibrate. If you want to ensure that you aren't dumping fuel into your forge when the flame isn't lit you can use flame sensors much like commercial furnaces do. I'm not sure, but a PID controller may even have a setting that can detect that no increase in temperature is occurring and shut off the fuel. I only learned the things I needed to make my oven function, so I'm not familiar with all the possibilities.
  18. For the first iteration of my DIY power hammer I used tow straps instead of a linkage. I wanted to minimize the number of metal on metal wear surfaces. It worked ok, but with the design I used it required fairly frequent adjusting/tightening to keep everything lined up properly. This makes me wonder if I could use a tire instead of the entire linkage/spring assembly. Unfortunately the tension on the linkage arms does affect how well the hammer runs, and I'm not sure there's a reasonably good way to change the tension on a used tire.
  19. Right. You got the surface area in square inches and then multiplied that times the thickness to give you cubic inches of volume. You can then use the density of Kastolite (lbs/cu in.) to calculate the minimum weight of kastolite needed for your build. It seems to me that you have it right (assuming you used the right number for the density of kastolite. I didn't check that). When you get it completed and ready to use, the whole thing should be on a frame or something to elevate it a little bit so that you can put a bed of dry sand or something else to contain any molten metal that would exit your drain hole if the crucible fails. You want nothing flammable or anything that could be holding moisture (like concrete) to come in contact with molten metal. Always assume that there could be problems and prepare for them so you won't be surprised and you will limit the potential for injury. Based on your postings on here I think you are moving in a generally good direction and speed on this. I know when I get excited about a project it's hard to slow down and do things the safe/right way. However, the success rate goes up and the injury rate goes down when I force myself to do that.
  20. I probably wasn't as clear as I could have been. You can cut a couple inches off the bottom in much the same way you intend to do at the top for your lid. In fact they should both have a hole in the center, but a much smaller hole in the floor piece. What I'm suggesting is 3 separate pieces that comprise your melter. The bottom piece is the floor, which should have a drain hole in the center to allow molten metal to escape when there is a crucible failure. You can cast the floor with a small channel that runs to a hole that will be covered by the plinth that the crucible sits on. The middle piece is just the the cylinder with the burner, and of course the removable lid (ceiling) sits on top with a hole for exhaust gases to escape. It may be a good idea to use some combination of latches, clasps, or hinges to hold everything together in use, but once it's cooled down you can separate the pieces and service them or replace them individually as needed without having to rebuild the entire thing. I came up with the same number as you for the minimum amount of kastolite required for your build. Experience has taught me to always get more than I need because the chance of me doing everything perfectly the first time I try it is quite low.
  21. Unless your floor and ceiling are going inside the cylinder, the length (height) won't change. If you have a flat surface that you will set the cylinder on it won't take any additional space inside the chamber. The same goes for the top. They will still need insulation and refractory, but they can be removed/replaced separate of the main body. I suggest making it this way since it will be much easier to deal with if (when) a crucible fails inside your melter and you have to clean things up. In the worst case you can just replace the flat floor that the cylinder sits on and not have to rebuild the entire thing. I do agree with your math if we assume a 10 inch wall height though.
  22. I'm not sure I understand what you did with your math there. The cubic inches of the inside of the melter may be helpful for determining your burner size, but what you really want to calculate the amount of refractory you need is the surface area of the chamber multiplied by the thickness you intend to use to get the volume of the refractory. You said the diameter is 11 inches. After putting in 2 layers of wool your diameter is 7 inches. The height is 14 inches. you should be able to take it from there. After you apply .25" of refractory that will only leave you 6.5" of working space for your crucible and tongs. You may want to go shorter and fatter. I think starting with 14 inches in diameter and 11 inches tall would probably serve you better.
  23. Generally speaking it is a good idea to check with manufacturers regarding the uses of their products. I don't want to discourage that. However, as someone who personally tried to use one of the many refractory mortars/cements out there for my first propane forge, I can confirm that at least the brand I used did not hold up. Kastolite 30 is a good choice for a water setting high alumina insulating refractory material. It's rated up to 3000 degrees F and can be used as a flame face in addition to sealing in the ceramic wool fibers. It benefits from nearly 100% humidity during the curing phase. I usually enclose the casting in a plastic bag with a wet towel draped over the Kastolite material for a day or so to ensure that it stays as damp as needed for curing. Ambient humidity should not be considered good enough. Since you said you know close to diddly, it should be stressed that handling molten metal can be extremely dangerous - far more so than forging. It requires a fair amount of PPE to minimize the chance of serious injury if when something goes wrong. I have a limited amount of casting experience myself, but I would highly recommend trying to find a local college with a class or a local casting club/group that can assist you with all the particulars while you are getting started. All this metal working stuff can be really cool and rewarding, but it's not worth being maimed or worse due to lack of knowledge or protective equipment.
  24. A few things: Are you truly making a smelting furnace? In other words are you taking raw ore and ending up with a consolidated metal ingot? Or are you melting pieces of metal that are already mostly purified? This is an important distinction. First, it helps us understand what you are trying to do, and secondly different temperatures are usually required for smelting than melting. Next we need to know the metal that you are either melting or smelting. 2500 degrees F sounds really hot - and it is - but if you were smelting iron ore (or even melting iron for a pour) you would most likely exceed that temperature. For copper or aluminum it might be a different story. Next, regardless of what the manufacturer tells you, most of the refractory cements simply do not hold up for long under direct flame impingement circumstances. They are designed to stick pieces together rather than to take the brunt of hot, chemically active flames. I wouldn't be comfortable using something rated for 2500 degrees in my forge, let alone something that would require higher temperatures. The refractory I use is rated for 3000 degrees, and it's not uncommon to see people using something rated for 3200 degrees. Again, that's for forging/forge welding, which can be accomplished at several hundred degrees cooler than melting or smelting iron or steel. Depending on the type of refractory it is, removing the water more quickly doesn't necessarily give you the results you want. A lot of us use a water setting refractory that cures best (most strength and minimal cracking) in a high humidity environment. After a day or so of curing we do have to remove the excess water slowly by gradually raising the temperature. If done too quickly it can create steam pockets which can reduce the effectiveness of the refractory and/or actually explode in extreme cases. O/A flames tend to be very hot and somewhat focused even if you are holding the torch back 6 to 8 inches. It's really not the right tool for the job. I don't know if you are seeing the results of rapid surface heating creating steam pockets or something else, but in my opinion you do not have the appropriate material for the job either.
  25. Same thing in my area. There are 5 hospitals total in 3 cities within 30 miles of me, but all of them belong to one of two major health care provider conglomerates. Nearly all the urgent care, specialized care, clinics, etc. are also associated with one or the other. My PCP was in an independent practice with a couple other physicians when I started with him, but now he's also under the umbrella of one of the 2 major providers in my area. I think it's the health care industry version of the national chains squeezing out the "mom and pop" grocery stores and gas stations.
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