Welding Cast Iron and others - new to all of this

Should add to this post - demo I saw used pure propane (w/tip that helped it mix better with air), NO oxygen or other tank involved. Welding rods were

1/8" diameter or so (as I recall). Flux said to be "unique". Welds were solid. (Should have saved the demo piece, aluminum in this case.)

Considerable practice on something easier.

Google this ng. for past comments. The process is possible, but it needs practice. Small welds of the ends of steel bars to decorative iron castings are much easier to do well than repairing long cracks in castings.

No oxygen and a funny flux ? That's not welding, it's a brazing process. Useful in its place, but with limits.

"Andy Dingley" wrote

I believe that flux had some snake oil in it. And a secret ingredient known only to the inventor, and kept under wraps by the government who didn't want the secret to get out and disrupt the world economy.

Right?

Steve ;-)

great movie!!

This is the one/demo I saw here in Sarasota a year+ ago.

Anything wrong with it? (Dumb question, maybe - answer based on application!!)

Wayne

Fluorides usually. Effective, but rather more toxic than you want to be working with.

i don't know about anything being particularly "wrong" with it, though don't recall anything about the flux your original post refered to; in either case would figure age hardening/cold worked fractures could be the only potential drawback....

its cauled turbotorch iirc. i have one and yes it is very good, but it does NOT get hot enough to weld even with mapp gas (it can be used with mapp or propane) it will however braze with ease, and brazeing can be extreemly strong as well as haveing the advantage of being able to join dissimiler metals.

sounds very much like soldering or brazing. i have some 'magna 51' solder and flux that is suppost to be good for all white metals. the flux IS very good, but i have never been able to solder Al very efectivly (i have seen it done well though, so thats probably just me)

Oliver

I believe you are right! No flux involved - purely the brazing rod.

BTW, for someone new, what is the primary difference between welding and brazing?

As for my question about "what is wrong with this method", refer to strength. I suppose I should do a little Internet research on this subject. BTW, the site you referred me to noted that one should let the "braze" cool on its own. No quenching (is that the right word for splashing/dumping in water?)

Wayne

Went to the subject's web site. Flux is WITHIN the rod. Wayne

surface tensiion, temperature, fusion

Brazing is a generalised heating of the whole area, so that the filler rod melts and flows by surface tension.

Welding is a local heating, so that the parent metal melts locally.

It's sometimes said that brazing is a melt of only one part and welding is both melting, but there's a cross-over region of "bronze welding" which is a welding technique with the materials of brazing. This does have some diffusion of the two metals.