Sure, it's a Firepower Victor 250 and the rebar is 1/2"
Steve

OK, so after I made a big deal about needing to know more, I found a site that has a chart for thickness of material being welded to what size tip to use, and another chart that compares tip sizes in different brands of torches.

http://bikesmithdesign.com/Welding/Tips.html

Looks like a useful chart.

SmokyRick

Rick Crawford at Smoky Forge

Steve I take it by welding with O/A that you are going to use steel rod? Just curious if you are that is going to be a very slow process. In order to use steel rod that means that you have to have a large enough tip to melt the rebar for the steel rod to flow. It will take some pretty good heat and the problem with gas welding round to round is the gap between the two areas. You will first start to melt the rebar away from where they connect because it is hard to isolate the flame in the joint. Good luck if going to try that way.
Now on the other hand if you are going to braze using a O/A torch it will be much simpler. All you need to do is get the rebar glowing orange and then braze. Your heat does not have to be so penetrating. So start with a large tip and if gets too hot you can always try a smaller tip.

www Metalrecipes -- heat and beat to the desired shape, repeat as necessary.
warren

Yeah, steel rod. I think I will end up brazing - just looking at the tip sizes (thanks Rick) for 1/2 rod I would need a pretty big tip. Would brazing have sufficient strength for a chair?

You should be albe lto weld that 1/2" rebar using a #2 or #3 tip. You could use bigger or smaller, but really don't need to. A mdeium-sized tip will do fine. One thing: don't quench your welds, but rather let them cool naturally. Rebar has a medium high carbon content and will often crack if quenched.

want to know the details