What's the lite coating on black iron pipe?

SimS · Oct 20, 2019

Chinesemoline, Bunker Oil and a little diesel fuel.

wheelbuilder · Oct 20, 2019

Oil from cutting the threads ?

Mark @ Everlast · Oct 21, 2019

It can be several things. It can be iron oxide paint covered with cosmoline, or mill scale combined with lube used to protect the metal and help it along during the final handling process. If it's P and O. Pickled and Oiled, its not too much different that gun bluing in the final effect. The P and O process is popular these days because it is descaled and pickled so that it won't rust, and the oil covering it has lasts a longer time in the elements, without setting in flash rust. It's easily cleaned, and requires little or no grinding to prep the metal for welding.

5030 · Oct 27, 2019

DL Meisen said:
Brake cleaner is fine as long as it does not contain tricloralfourethene(sp?) It's the "tri-clor" that converts to PHOSGENE (nerve gas) when introduced to flame/arc ...

Dale

Must be why I shake sometimes and I thought it was my age....

Tractor Seabee · Oct 27, 2019

DL Meisen said:
Brake cleaner is fine as long as it does not contain tricloralfourethene(sp?) It's the "tri-clor" that converts to PHOSGENE (nerve gas) when introduced to flame/arc ...

Dale

This is the case with any chlorine containing compound. Refrigeration workers have to be careful brazing on copper tube that contains or has contained chlorinated refrigerants. I know from sad experience. Week in the hospital and 3 weeks healing my lungs. Came close to dying, I was crazy back then, drove myself to the hospital. Bad stuff, worse than galvanized poisoning.

stuckmotor · Oct 27, 2019

I already had a suitable container and white vinegar so I put some of the greasy, sooty, pipe in to soak and didn't get back to it for a week. Then finished it up with dish detergent, water, a stainless scrub pad and paper towels. I've only soaked painted pipe for a couple of days and it was less trouble to finish cleaning, "I didn't use a stainless steel pad". Next time, I'll probably skip the vinegar and see how things go.

HillStreet · Oct 27, 2019

Welding fume is never good. You should be ventilating away from your breathing zone.

Tractor Seabee · Oct 27, 2019

I have done thousands of joints on varnished steel pipe in my career. never did anything except burn it off around the weld area with the torch. When flame cutting we had to burn it off to mark the soap stone line so that handled that joint. Just don't put your head in the smoke or wear a dust mask (pain in the rear).

Ron