Buzzkill

There's a rather lengthy thread in which quite a few options have been discussed, analyzed, dissected, etc. Quite a few options would work, but raise safety concerns. https://www.iforgeiron.com/topic/19531-freezing-propane-tanks-a-different-solution/?tab=comments#comment-200771

Welcome to the forum Wesley. It's a good idea to update your profile with your general location since the answers to some questions are location specific and people from all around the world participate here. What is available to me within a 10 minute drive may not be available at all in another part of the world. If you are on a budget then I would think that propane in bbq size tanks or larger would be much more cost effective in the long run than what is called MAPP gas in small cylinders. If you have your heart set on using MAPP and a torch I can't be of much help. On the other hand if you are interested in relatively low cost up front and more savings over time then we can help. For a low cost, yet effective propane burner I can wholeheartedly recommend the T-burner designed by our own Frosty: https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/ If you have at least some small amount of tools and know how to use them you can build these burners for less than it will cost you for the torch you are trying to find. As a bonus you get to talk to the designer to help iron out problems and help you get it tuned properly. I'd also highly recommend reading through Burners 101 and Forges 101 to help you understand the principles and terminology better. https://www.iforgeiron.com/topic/46536-burners-101/ https://www.iforgeiron.com/topic/47439-forges-101/ Unfortunately a lot of the videos and plans posted online are less than ideal, and some are downright dangerous. Some may look cheap to build, but in the long run they will be far more expensive to operate due to using inferior materials and/or poor design. Grab a comfy chair, a cold drink, and some snacks then spend a few hours reading through the topics I listed and any others that catch your attention. We can't give you back the money you spent already, but we can help you avoid unnecessary costly purchases in the future. It just takes a little time and patience to get up to speed.

When I occidentally overcooked my rice it turned to mush. Just sayin'

My gas forges get too hot to comfortably hold your hand on the outside of the shell for more than a moment, but never hot enough to burn off the original paint - except near the openings. I would not use aluminum or other low melting point metals unless the shell near the opening was protected by some form of insulating material, and even then would still recommend mild or stainless steel instead.

You gotta have fun with these people. When I have the time I waste as much of theirs as possible. When people call to tell me they can save me money on the phone bill or the electric bill I always ask them how much I'm paying now. Of course they can't tell me that and ask me. I say, "You told me you could save me money. How is that possible if you don't know what I'm currently paying." Then I act interested for a while and string them along. At the end of it I tell them I like the more expensive phone service because the calls are clearer and the rings are louder. If it's about the electric bill then I tell them the lights are brighter and the computers run faster with the more expensive electricity so I don't want to switch. Asking them to hold repeatedly in the middle of all that is classic too. If they want to talk to a person in a certain position at the company I ask them to hold while we go hire someone for that position. The bottom line is if they are willing to waste my time I'm willing to waste theirs too if I'm not already in the middle of something.

It doesn't take much to change the behavior. If you are just a hair off in jet alignment it can have an impact. MIG tips can have minor differences in orifice diameter. The point is that very small changes can have a noticeable effect. The smaller the diameter of the burner the more minor changes can have a significant impact in performance.

From what I saw the burner behavior is normal at low pressure. The flame was burning inside the tube and that creates the pulsing/chirping sound. Once you turned the pressure up the flame was burning at the end of the tube as it is supposed to do. At low gas pressure there isn't enough velocity to pull in the appropriate amount of air. The problem is not enough air, not too much. It's not really a problem though since (in my experience at least) you'll be running higher pressure than that when forging anyway - unless you have way too much burner for your forge. Also, keep in mind that the burner will behave a little differently inside the forge due to additional back pressure.

If the only issue is speed you can always use a smaller drive wheel on the motor. If you have a 3600 rpm motor on there you could cut the speed with a motor that runs 1800 rpm.

If his semi half cousin Ford shows up the probability increases dramatically.

The pinned topic in this section will answer most of your questions. However, there may still be a couple things that aren't clear to you after reading it a couple times. For normalizing I heat to non-magnetic and let it cool down to black heat (not cool enough to hold in your hand) before reheating back up to non-magnetic. If you detect a warp immediately after quenching but your blade is still several hundred degrees, you can usually straighten a slight warp before it cools to room temperature. This is a little risky and you can snap a blade if you go to far. There are a couple other methods of straightening without repeating the whole process. Some people clamp a warped blade between two straight pieces of thick flat stock and leave it that way for tempering. You may also want to look into the "3 pin" method in which you isolate the warp and heat only the spine to straighten the blade. I've asked a similar question on here before and was told (by Thomas Powers I believe) that number of times steel is brought to a certain temperature is more important than the time spent at temperature. One of the reasons for the suggested hour or more at temperature is to make sure the entire piece of steel has been thoroughly tempered. A word of caution if you draw your temper using the color method: Once the colors start running, they go very quickly so make sure you have water or some other quench medium immediately at hand to stop the temper at the right spot. If the steel is only a few hundred degrees in temperature it will not hurt anything to dunk it in water or any other liquid that will take the heat away. Also, straw color is correct for some alloys for knife blades. It would not necessarily be correct for other alloys or applications. You'll have to look up the heat treating information for the specific alloy you are working with in order to know the proper temperatures to get the most out of that steel for your intended application.

It bears more than a passing resemblance to the Daedric dagger in Skyrim. Not sure how practical it is, but it is some interesting eye candy.

Any idea as to the purpose of the table salt? Chlorides are notorious contributors to stress corrosion cracking (even in stainless steel), so I'm a bit puzzled as to why it would be included in the recipe.

Congrats Theo! Can't wait to see you tell some more blacksmith jokes

Looks a lot like the results I got when using a refractory mortar for the lining of a gas forge. It was supposed to be rated to 3000 degrees F, but at high temperatures it got sticky, kind of like peanut butter, and when it cooled it was glass-like. You don't really need something like that in a solid fuel forge anyway. Dirt/clay/ash should do fine without any refractory coating.

We have a different understanding then. My understanding and limited experience is it works better to place the end of the burner or flare about a half inch inside the the shell, give or take a little, which puts it about 2 inches from the forge interior if you are using 2 inches of blanket and a half inch hot face material. I usually cast the burner ports with refractory material though, so there is refractory from the shell to the forge interior in that one spot.

I've never used them, but I am interested in your opinions after using them some, so please keep us updated if you have anything further to add.

Don't get too concerned about the flame wanting to blow itself out - as long as your burner is tuned well. Once the inside of the forge is glowing hot the flame pretty much cannot blow itself out any more. I generally let mine run about 5 minutes or so on fairly low/stable pressure before turning it up. Once it's glowing hot inside I can go to max pressure with no problems. If I did that when I first light the burner it would definitely blow the flame off the end of the burner. You may need to trim the tip a little. Your flame looks to be on the rich side to me, but I don't consider myself to be an expert in burners or interpreting photographs of their flames.

John, This forum is read by a lot of people. Even if we understand what you mean, other people who read the forum may not. Some of the terms have a specific meaning and if we conflate terms then it gets very confusing to others. There are differences between forging and forge welding in both the desired outcome and the temperatures used. When forge welding we are typically using a significantly higher temperature than we would be forging at, and we're just trying to get all the pieces stuck together so that we have one solid piece of steel. We're not really trying to manipulate the shape of the steel at this point. When we forge we will usually lower the temperature and move the metal into the desired shape. We don't do that until we're reasonably sure that we have created one solid piece of steel. Attempting to forge before successfully forge welding will cause your billet to separate (delaminate) and you'll have to start over.

Is the sputtering happening only at low pressure, high pressure, or throughout the operating range? Is there any chance a breeze (from any source, even a fan) can reach the air intakes? It doesn't look likely that you have an issue with recycled exhaust gases, but that is a possibility. If you have the 2nd burner built already you may want to try it to see if the symptoms persist. That may help narrow down the possibilities.

I am not going to try to read his mind. I don't think he knows or understands enough yet to help us help him. On the one hand he talks about "melting cups" and melting scrap steel in order to produce a bar of iron, and on the other he says it's not casting. It's not smelting from ore if he's talking about melting scrap pieces, and if he's going to melt the scrap pieces then he will effectively be casting the liquid unless he's interested in crucible steel. I told him where to look to get an idea of what is involved there. He also says he wants to do what they did with their scrap in medieval times and referenced melting it again. We're pretty darn sure that in general scrap pieces were forge welded together and then forged out for use. Until he learns enough to know what it is that he's really after I'm not sure how much more we can help.

When you fire it up again, if it starts out ok, but then goes back to sputtering it's not likely to be an obstruction. If it sputters immediately again and won't burn at the end it could be. Even though you cleared it out, if a small particle came loose and lodged in the jet you could get those results. Most likely though it does have to do with the flare being down inside the forge.

One thing he has done is to extend his flare into the forging chamber rather than just past the outer shell. This makes it likely that over time the burner tube will get hot enough to ignite the fuel/air mixture inside the burner tube rather than at the end. The longer that continues, the closer to the jet ignition can take place. A couple other things that can cause those symptoms are a fuel tank that is nearly empty and a fuel tank that has cooled from the rapid use of the fuel so that the pressure has dropped too low to produce a stable flame at the end of the burner. Yet another possibility is an obstruction in the fuel supply line or the jet itself.

I can only use the information that you've given us. You've specifically said you wanted to know about a "melting cup" for iron or steel. Melting is not just changing the physical form, that's changing its physical state. If you just want to re-shape bits by getting them hot and hitting them with a hammer, that's forging. If you want to take 2 or more pieces of steel and turn them into one piece of steel without them becoming liquid, then that's where forge welding comes into play. Either of those two options are much easier to achieve and much less dangerous than taking them from the solid state to the liquid state. I would strongly encourage you to look at those options to get what you want rather than trying to deal with molten iron or steel. Thomas Powers can tell you about the medieval ways probably, but I'd guess they were much more likely to forge weld scrap pieces together than they were to melt the pieces.

Got it. What I'm telling you is: 1. Forging aluminum is not good practice for forging steel. They don't forge at the same temperatures, they don't have the same color spectrum to judge when it's ok to hit with a hammer, and they don't react the same way under a hammer. 2. Casting aluminum is not adequate practice for casting iron or steel. 3. There are many other ways of creating a cube of steel, if that is your preferred starting shape, for forging knives. 4. Cast iron or steel is almost certain to be less than ideal for making knives. 5. Steel that is suitable for forging (or stock removal) knives is readily and cheaply available - especially compared to melting steel. That's a short list. If you are really interested in what's involved in melting chunks of steel to a well-crafted steel weapon - in this case a sword - I suggest you look up and watch Secrets of the Viking Sword. Our own Ric Furrer is featured in that program. It was produced by Nova, but I believe part or all of it is on Youtube. That will give you an idea of what it takes.

That's not anywhere near a 4 inch cube unless that is one massive coffee mug. If you're talking about using aluminum foil and/or soda cans for casting aluminum ..... well, you should probably do a little more research first. I'm not saying those things can't be used for casting, but they are far from the best options. The points people made about liquids that can flash to steam in molten metal become very relevant when you talk about using aluminum cans. I'm not sure how the subject relates to knife making either. Regardless, can you explain why this needs to be cast steel rather than milled, ground, forged, forge welded, or other means that are far less likely to disfigure you, require a fraction of the energy, have far less chance to fail, would cost only pennies on the dollar (comparatively) to produce, and require only a small amount of PPE?