Hi again, tomorrow I'm going to exchange my propane tank for a full one, and found on the Blue Rhino website that a gallon of propane will last about 3 hours if the demand is about 30,000 BTU's per hour. So what's the demand for forging?

Second, Would grinding an old tool, like a cold chisel down to a hot chisel by increasing the angle of the edge, while keeping the tool wet while grinding keep the heat-treatment? I was thinking of taking old chisels from a flew market and grinding them down into hot chisels and slitting chisels. And maybe using some big ones for 'hawk heads.

From my experience, I have found that if you don't change the color while grinding, you don't change the hardness. Thats provided you don't grind past the heat treat. Most chisels are heat treated on the "business" end and left relatively soft on the hammer end. Hence the mushrooming of the hammer end. This is essential for a safe tool. If the entire tool was hardened the hammering end could shatter when hit. Where it is treated too depends on the manufacturer but I would susspect it extends at least through most of the taper.

So there wouldn't be much of an issue turning a cold chisel into a slitting chisel then, because I wouldn't be grinding much on the "business end"

Unless the color changes when you grind it the temper will be the same.

Why are you worried about the temper, if you intend to use the chisel on metal that is way hotter than the grinder will ever get it? I don't see any reason why the temper matters on hot tools after all they just need to be cooler than the metal your shaping to work anyway. Wouldn't it be easier to forge the chisel to shape then clean up with the grinder?

It seems to me, that if you want a tool for hot work, it should be hard enough normalized to do the job, because thats usually how it ends up, unless you are using specialty steel.

I use those chisels for tools all the time, but I forge them to shape. Forging is fun, grinding is just dirty work. Generally don't bother with any heat treat but a "floor anneal". Works fine for my serious-hobby-but-not-production use. Ever so often I do have to regrind the edge, but that's just a couple strokes on the grinder, not turning a mass of steel to grinding dust.

Steve

Oh yeah, and I typically get 9-10 hours from a 20-lb tank in my single Reil EZ-burner forge. From all the other times I've talked with folks about fuel consumption, your mileage will almost certainly vary.

Steve

Im getting about 5 to 6 good hours with a 20# with my gasser, thats at 5 psi.
With propane cost going up and up, im making a more efficient forge soon, i cant afford the 20$ gas bill every time i want to forge.

-Andrei

Out here you save at least $5 by getting a bottle refilled instead of exchanged and the refill place doesn't care who's bottle it was originally---I used to trade my old bottles needing inspection at a place like BR and then take the nice bottles to the refill place from then on.

Thomas

LOL...

That's exactly my strategy too. :D

See with propane forges and coal forges(as coal is going up too), there is that huge difference of(for this example a hand crank blower, or air grate flapper, take your pick, mine is hand crank so that's what i'll use for the example), when you stop cranking and turn to forge, the forge stops burning fuel at a high heat rate. There should be some way to make something for a propane forge that makes it so that when you step up to the forge to heat something up, you can put your foot on a pedal, which adds more propen and/or air , and when you step away that pedal is not pressed decreasing the amount of propand and/or air. I do not know much about propane forges and burners, but I guarentee there has to be a simple way to fix the problem of the forge burning super hot at your back and waisting all that fuel while you are forgeing.

Take a look at gas savers for OA torches; unfortunately a lot of the heat transfer to the work in the forge is from the lining and so letting that cool off can make a big difference in how fast your cycle time is.

Thomas

Ron Reil showed an idle circut for his forge. Should be on the Abana Site. he T'd off the main line through a needle valve and then T'd back into the main line. He had a ball valve that this circut went around. He would throw open the ball valve when he wanted to forge. when the ball valve was closed a small amount of gas went around through the needle valve and kept a small flame lit.

I have found that if I shut off the propane and then get back to it while there is still red inside, the forge will generally relight. I also decided that I should just keep feeding stock into the forge so that something else is heating whilst I'm beating.

Mills, I do the same thing. I have 2 burners on my forge, so I always try to have SOMETHING under each burner while I work Even if it's just a piece of scrap stock for practicing a technique on. In terms of slowing doen fuel consumption, I turn down the regulator and decrease pressure if I don't need to extra heat. And I have also found that the forge will relight if the chamber is still hot enough.

Here's a copy of the idle/full piping schematic for propane burners. I use this same set up on my two burner forge.