G-ManBart wrote:
One of the true experts who has posted on most of the welding forums once did a writeup about welding with wet 7018 rods. He soaked old rods in a can overnight to get them completely saturated, then used them. He would pull one out of the can, put it in the stinger, stick the rod to the work and let it cook until the steam would release, then break it free and weld a perfect bead. He did cut and etch as well as bend tests and they were perfect.
According to what I read about them they shouldn't even start. But if they passed a bend test I'm fine.
What's the member's name? I would like to read some of his posts.
As MinnesotaDave mentioned, it was CEP who posted that on Welding Web and I think shared it on the Garage Journal Forum as well. I haven't seen him post in a while, but he helped me a bunch when I was first starting to learn how to weld (still learning!).
Just found these again while looking for something else, if anyone is interested, some tables that show thickness limits in relation to preheat, hydrogen and material composition. Taken from BS EN 1011-2:2001, worth a read if you are interested in weldability of steels. Can skip straight to the the appendices, which are three quarters of the document, for the interesting stuff...
No Preheat
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Creep Resistant
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Low Temperature
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Not so much shattering. Cracking is the risk. Used to manufacture meat carton freezing tunnels and spiral freezers operating at -40degrees and below. All standard mild steel sections but all mig welded.
Interesting to note regarding refrigeration pipework (ammonia), at around -30 degrees C we have switch from the normal A53B/A106b pipe to A333/A334 low temp rated pipe.
Something to keep in mind, there isn't any voodoo that happens when a 7018 picks up some moisture as compared to a 6010 for example that has moisture in the flux and actually weld like crap if the flux dries out. In other words, a moisture stricken 7018 isn't going to be any more prone to hydrogen cracking than a fresh 6010, 6011, 6013 etc right out of a sealed can.
I may be mistaken as it's been a while since I've looked into it, but I also believe hydrogen cracking is more of an issue with low alloy/higher strength steels. Plain mild steel IIRC generally doesn't suffer from hydrogen embrittlement.
Just how exposed to moisture they are will make a difference though, I can tell you first hand that an open cardboard box of cheap 7018s that has been sitting in a truck for a year down in the south will weld like crap, you'll often get constant pinholes through the entire weld. Generally moisture resistant brands of 7018 will hold up a lot better when left out in the open.