Welding Tips and Tricks

Recently I found a good deal on a used, but fairly new Miller Thunderbolt machine. It was being sold with two hoods, a leather upper-shirt, and two plastic tubes of various rod. Upon closer examination of the rods, they appeared to be some weird stuff from Harbor Freight (Chinese).
Yesterday, I decided to use some of this rod on a project I was working on. This stuff was crap! When it wasn't sticking like super-glue, it was spitting out the worst beads and leaving slag I needed TnT to remove. Needless to say, ALL of this rod is now in the trash can. I highly recommend only buying rod from well known sources such as Lincoln or Weldmark.

I don't buy Chinese metals at all (they'll smelt any old scrap and give it an alloy designation), when I can help it, but if these sleeves were open (for God knows how long), moisture in the flux may have "helped" with the problem. You cannot "restore" 7018 by baking the moisture out, but you can improve it for general-purpose welds.

For 7018, my favorite is Lincoln-Electric "Excalibur", which I believe are now made in Mexico, but without a rod oven, they don't keep. On an ASME coded job, you typically have four hours to use the rod after it leaves the new can or the oven, or it's considered scrap.

Steve S

I have to disagree with you to a certain point here Steve. The thing that makes a 7018 a 7018 is the flux (the "8"). Otherwise it could be a 7010 or a 7014 or a 7024. The common thread in all of them is the steel core, the actual rod. The fluxes are designed not only to shield the molten steel but to have cooling and chemical effects to it as well. By code standards that I know you have had to follow and have cited before there is no restoring 7018s. And I will say for sure that an old one or a wet one will not perform worth a pile of dog poo. But if you were to bake a 7018 for a while then use it before it cools or keep it from ambient moisture or keeping it warm on a regular basis and definitely right before use; you would be hard pressed to tell much difference in it from a new one. The thing is that it is still a 70,000 psi rod for all position. By baking it you are just removing the moisture from the flux that has a tendency to attract it. That still does not excuse junk chinese welding rod. I buy all lincoln 6010s and 7018s. I wont run any other rod unless it is life or death. But I do say you can make a 7018 respectable if not comparable but baking it and warming it before use. The biggest key is the warming it before use. Thoughts?

The problem isn't water, it's a hydrated salt created in the presence of water. It's an actual chemical bond, not just absorption. That's why they require 400+ degrees F for 30+ minutes or whatever in order to refresh the rods(and that may still not meet code, which is why you see cases and cases of rods discraded at the end of construction). It only takes 150+ degrees or so to keep the rod from absorbing in the 1st place, just like how a dehumidifying rod works. S/F.....Ken M

Yup.

7018 is a "low hydrogen" alloy. As soon as the flux absorbs moisture to it's core (the alloy), about four hours in a warm high-humidity environment, it's no longer "low hydrogen", suffers from effects of hydrogen embrittlement, and is no longer 70KPSI in strength.

Thus the trashed cans on coded jobs.

And, yes, if you go straight from can to oven, you can avoid this, though I've never seen an oven on a job set below 225F. (As Jody says, there's no kill like overkill.)

Steve S

Ok well the part about the sulfur crystals is new to me. I do know that trying to restore the rods by baking them doesnt work on rods that are old. And by code standards when they want "low hydrogen" which is what 7018s are meant to be I will agree that you should not try to restore them and follow the rules of warming or whatever they want for them. However 7018s make a quality rod for lots of general welding and restoring them is a wide open possibility. Apologies for my ignorance. I do know what has worked for me though and code doesn't affect a lot of my repair work so until I have acode to follow or engineer to keep happy I probably will not worry about keeping my 7018s in an oven all the time.