View Full Version : Heating to bend rebar

11-02-2006, 09:08 PM
I am going to make a Christmas light thing that will go in my front yard. My parents have one so I will use it to copy off of. It is going to be lighted carrolers made out of rebar( Ill post a pic so you know what I am talking about). I am going to heat the metal so it will be easyer to bend. The problem is I dont have an oxy/acy set up. I am going to buy something to heat the metal and was just wondering what to do. Here is what I want to do. All I need is a rosebud for heating, no cutting tips. With that said what do you think about using propane to heat the rebar (I think propane would be safer to use than Acetylene).
1. Would propane be hot enough with oxygen.
2. What about the 1/7 rule. does that just apply to acetylene bottles, or does it apply to oxygen bottles. Also would the rule apply to propane bottles.
3. What torch do I need for propane and lines.
4. how much would this cost for the set up.

Il post some pics in a few minutes.

11-02-2006, 09:17 PM
Ok here is a pic of what I am going to make. The only hard thing about it would be wiring all the lights. It is just a metal frame with lots and lots of light zip tied on them.

11-02-2006, 09:26 PM
I would recommend using Mapp gas instead of Propane. Mapp gas peak flame temperature is around 5300 F vs 3600 F for Propane.

11-02-2006, 09:43 PM
Howdy Howdy! I suggest the smaller 3/8" rebar size stuff. also, you can rent a rebar bender from your local tool rental really cheep. it's just a high leverage mechanical bender, works really slick, no heat involved. It has a sheer also built into the head. Or, you can get the HF benchtop bender for around 50$ when they go on the usual HF tool sales. this tool bends all sorts of stuff! not just rebar. no heat required. if you REALLY think you nead a torch due to other projects, then go ahead and get one of the quality name brand, OR the in house brand from your local welding store. I know Radnor brand for instance truly are made bye victor. And if you get a good deal, you can usually get a set for about 150$. alot of times for smaller projects, I'll just use a cutting head and not press the cutting lever. That gives me tons of heat, without have a specialty rosebud. All the victor sets now come with hose and guages rated for all fuel gas. something to be aware of. Also, the 1/7th rule does not apply to propane/natural gas, or anything except acetylene for that matter. It applies to acetylene because the gas is diffused in liquid acetone, and anything more then 1/7th the tanks volume and then you start to suck out the acetone, causing a gradually less and less stable fuel system. you can get a set, and then purchase a propane cutting tip, or propane rosebud. that'd be a great choice. also more economical then oxy/ace. As far as temperature goes... propane is awesome. alot of blacksmiths use propane forges now. Also, propane puts out more HEAT overall, and over a much broader area then acetylene does. However! it is good to know, though not applicable for you, that acetylene burns much hotter at a very specific ratio, and very near the inner cone. If you go with a used torch set, then make sure the hoses are rated for propane, and especially the guages. sometimes it's hard to tell. hope thats a good start. Good luck! Brian Lee Sparkeee27

11-02-2006, 09:59 PM
Howdy Howdy! what I have here, in my Lincoln welders bible, is
welding arc = 10,900 oxy/ace flame = 6,330 oxy/hydrogen flame = 5,070 natural gas/oxy = 3,360 AND Iron melts at 2,802 degrees, all in feirenheit. Oxy propane is used in the cutting of steel in industrial processes more then oxy/acetylene due to it's safer handling, easier storage, and lower cost. Oxy/propane should work just great! Now if you compared HEAT output, you actually get more "work done" or energy transfered into the material to be heated with propane then you do with the much hotter acetylene. Propane is not used for welding, due to the lack of carbon content after welds are attempted with propane. The steel is now embrittled, and no longer steel. it becomes an Iron-ish pot metal mix. Brittle and crappy. about like the stuff newer crap steel bed frame angle "crap iron" is made from. but thatis ONLY if you attempt to weld with propane. Propane is also very awesome for brazing, as it is much cleaner burning flame. Your BBQ propane tank would suffice just dandy. your regulator would have the same fitting for BBQ tank as an acetylene tank does. Good luck! Brian Lee Sparkeee27

11-02-2006, 10:09 PM
Hey Brian,
Can you post a pic of a rebar bender.
I have a cheap pipe bender will that work?

11-02-2006, 10:10 PM
Use #3 (3/8"),and a pipe to slip over it, and you can do that whole thing using the pipe and your bench vise. The #3 bends easy that way, and I do it all the time. You'll quickly develop the technique for smooth, gradual bends.:)

11-02-2006, 10:17 PM
Good idea.
I will try it.

Do you use heat. or no heat.

11-02-2006, 10:43 PM
No heat, except for tight 90 degree corners, and then my 5 pound hammer can usually coax them over cold in my big vise.:)

11-02-2006, 10:47 PM
Yeah, I cured him of wanting a rebar bender......didn't I, Evapfoot?;) :D :D

The benders work great for what they are designed for...bending bar in slabs or other concrete work. They aren't really very good for making controlled bends.

11-03-2006, 07:13 AM
Yup! I tried arebar bender at DDA's shop, and was glad I didn't end up making one after looking at them at Home Dee-Dum. My Ridgid Conduit Bender ($3,00 at thrift store) works as well, but I seldom even use that. I have four lenghts of pipe, and one is 1 1/4" 'ovaled' in my press, which allows me to slip it over rebar that has some bend stated.
My rebar bending method (#3 bar) is to start at the portion of the bend awayfrom the end, and tug N' slip an inch at a time. Works great!:)