Hi,

I'm using Silver-flo rods and Easy Flow flux to connect pieces of mild steel.

My heat source is a 1/2" Bullfinch torch fed from a 7kg Propane cylinder.

So far so good you might say, and very often it is. The flux forms a silvery appearance and the Silver-flo rod runs nicely into the joint.

But …. every now and then the flux goes black and the Silver-flow beads up and the joint doesn't make.

At this point I have to scrape off the black residue, clean up the metal again and hope for the best.

What am I doing wrong?

I've tried using a Borax flux with the same results.

regards

B

Thanks Fizzy, I'll get some Tenicity.

I must admit that I do find it difficult to get quickly to temperature, so I do finish up cooking the metal for quite a while.

I am using Silver-flo 40 (which I bought in error) which probably doesn't help.

B

A bigger burner will have to go on my birthday list.

As I usually only 'cook' small pieces of metal I've found the 1/2" nozzle to be adequate.

The one which prompted this post was 1/2" square x1/8" thick being attached to a 1/4" round rod – much like a key blank and I thought it would be a doddle – but it took ages to get to temperature.

Anyway thanks guys – at least I have some food for thought and future improvements

regards

B