cleaning metal for welding

I've found oxy/ace welding to be quite tolerant of dirty material. Big globs of paint and grease should be removed, if for no other reason than it sucks to breath the fumes. Surface rust should not be a problem though.

If it's a question of technique, you should practice welding some 12 or 10 ga. steel sheet together until you can get a nice strong and pretty joint. Then move to rebar.

Oxy/ace will do what you want, but mig might be faster and easier.

some sculptures and it's surely a lot more work to clean off all the gunk first.

Its probably what your welding, not the dirt thats stopping you... Rebar is junk metal...

From *my* personal experience... I'd say get yourself a little 4" angle grinder and use it.... It is not only easier to get a nice weld with clean metal, but I would almost bet that you can get the metal heated up to welding temperature faster and be able to move along faster with clean metal..,.. rust seems to act as an insulator and just makes the job take longer. Also, rebar probably isn't the best stuff for you to try to make sculptures from - it's pretty hard to determine what kind of junk is used when making them (although there are different qualities of rebar). Hope this helps. Ken.

You might even find some that will glow in the dark. Gerry :-)} London, Canada

I doubt that rust is your problem. Clean metal is important if sound welds of best strength are the objective, but that probably isn't a priority in most sculpture work.

A more detailed description of what's going wrong might gain you more useful guidance.

It seems to take longer than needed to get the metal to join together. If I take bolts of the same diameter than the rebar I can get them joined much quicker. As I'm heating the rebar it seems as if the surface has spots that are brighter than the underlying metal, almost what lava looks like. I'm thinking this is the rust/dirt that is acting like an insulator..?

Thanks all, Adriaan

What's the history on your rebar? Does it have any adhering concrete? As in salvaged from broken pavement?

bob g.

Joe wrote:

Yes, if there is more than just light surface rust. I've watched a muffler mechanic cut the outer pipe of two telescoped pipes with an O/A torch without cutting the inside one. I was amazed. He said the rust insulates the inside one. I've tried it myself, and was successful.

Also, there is some steel that is just plain difficult to weld with gas. My daughter had an imported tricycle that broke, and I could

*not* get that sucker welded back together. (All I had at the time was an O/A torch) I finally brazed it.

It *has* been lying outside for a while, but no cement that I can see. Just rust & dirt.