Buzzkill

No problem. I took 3 of these apart a few days ago. I ended up caging the chamber, cutting the pot band all the way around to remove the pot and spring, then put the caged spring & pot in a press (spring side up). Once I pressed enough to take the tension off the caging bolt I removed the nut and let the press open up slowly. Worked like a charm. Just FYI, the spring in its relaxed position is about twice the depth of the pot, which is about 3 inches or so longer than the caging bolt. Now I have aluminum for casting and spring steel for a number of uses. It's a bit of work, but it's a win-win for me as long as I can get them for free.

DSW, the caging bolts that come with air brake chambers are too short to relieve the tension in the springs if you cut the pot loose from the aluminum piece in the middle. Someone could get seriously hurt if they tried to cage the spring, cut the pot loose, then remove the nut from the caging bolt. There will still be a LOT of spring pressure in the system when you run out of threads, which will create a dangerous projectile situation.

I'm going to be melting the aluminum down for other projects anyway, but the press does sound like a much safer way to go as long as I can keep it from bending in the middle while decompressing the springs. SmoothBore, great idea. I think I'll fab one of those up and give it a try. That should be a little bit easier to use than the horn of the anvil. Pat, right now this is a weekend hobby for me and the family budget doesn't tolerate much additional expense for it. I can get these springs for free and in general I like to use what I already have or can get for free rather than buy new stuff. But you're right of course. It's a lot less work to purchase what you need or close to it. On the other hand we could also purchase a lot of the things we make, but where's the fun in that?

Thanks for all the info. I really appreciate it. Charles R. Stevens - quick question. What do you do to get the springs out safely? I was thinking about placing them on the forge to heat the pot and springs up to red hot to relieve the tension. The spring was broken in the one I took apart so far, but I'd really rather not injure myself getting at the rest of those springs.

I think I have the idea now. Thanks for the speedy replies. Hopefully I'll be able to give it another shot this weekend and get the desired results.

Right, but I'm trying to maximize width expansion while minimizing length expansion. The volume remains constant, but I'm trying to find out how to move the metal into the shape I want in the most effective way. I believe what I have already done reshapes the steel in a way that produces roughly the same amount of length expansion as it does width expansion. I think patrick understood what I was asking and was steering me in the right direction. I just wanted to be sure that I was clear about his advice.

Please forgive my ignorance, but I could use a little more explanation. If I understood what you are saying then a 0.5 inch diameter rod could theoretically produce flat stock a little over 1.3" wide at 0.15" thickness. Obviously that would be impossible to produce, but that's the limit according to the math. I did use a flat faced hammer for this. If I were to switch to a cross (or straight) peen hammer then I think what you are saying is strike so that the peen is parallel to steel on contact and work side to side to get greater width than length expansion. Did I understand that correctly?

I'm sure my question will make it obvious that I am a novice, but here it is anyway: Is there a good or specific hammer technique that will result in growing the width of steel faster than the length? I have access to a fair amount of round coiled half inch spring steel used in the brake chambers on semi-tractors and trailers. After straightening and pounding a length flat I ended up with about 0.9" width at about 0.15" thickness. I had really hoped I would be able to achieve a little over 1 inch width at that same thickness. For short pieces I'm guessing I could upset the steel to some degree before pounding it flat, but hopefully one of you veterans has some tricks of the trade that can help me get more width from those springs without folding the flat pieces back on themselves and forge welding. Please let me know if you can shed some light on this for me.

I'm just getting into blacksmithing/forging and the cheap (free) cost of waste oil has me working in that direction. My first attempt at a waste oil forge worked to some extent, but I determined I did not have a thick enough refractory lining. I also located the burner input centrally, which created a cool spot where the fuel was being injected into the forge -- which is precisely where you don't want a cool spot. The chamber dimensions of this forge were 8 inches diameter, 9 inches in length with the work opening of 4x4 inches centered in the tube. I'm using a siphon nozzle setup which pushes compressed air through a .023" mig tip and a 5/64" hole in the plug which is the burner tip. The design of the burner is based on this: http://www.youtube.com/watch?v=E-l21wQ6X-E&feature=youtu.be The blower I use is one I removed from a power vent water heater. I ran the first forge on kerosene initially, but to get the heat I needed from it I ended up with a flame roughly 2 feet long shooting out of the forge. I never switched over to waste oil due to the design flaws in the forge. What I'm trying to do with the current design is keep most of the flames inside the forge, be able to burn waste oil, and reach forge welding temperature. The design I'm working with now still has an 8 inch diameter tube, but I've increased it to about 11.5 inches in length and I've got enough room for a full 3 inches of refractory in all directions. The burner will be located at the rear of the tube to avoid a cool spot in the center. What I'm wondering about is the appropriate opening size and location for inserting billets for heating. The opening I have planned now is 4 inches wide by 3 inches tall and located near the bottom of the tube (which is horizontal). I plan to completely seal off the back end. Is it better to have a small opening like I have planned to help with heat loss or will that potentially create combustion problems at that size? Sorry, but I have no pics at this time.