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Post by rccolacc on Dec 5, 2007 0:16:22 GMT -5
I just bought some welding rods at NexAir earlier today-- 5lbs of 6013 and 5lbs of 7018. I've always bought the sealed boxes of them at Lowes, but at NexAir you buy them by the pound and they just come straight out of a huge carton (not sealed package). Well I tried a few rods of both tonight, and the 6013 rod looks good and sounds good when I weld. The 7018 however had a lot of cracking and popping. The weld looked OK, but it seemed to have more spatter and sound more like a 6011 rod when I was welding. I'm used to a smoother sound when I've welding with a 7018 rod. I noticed the 7018 rod says E7018-1 on the tip of it. Does this mean it's different than a regular 7018? What's the 1 mean? Is it making loud cracking and popping noises because it has a lot of moisture in it? I have no idea how long the rods have been in the open carton at NexAir. I'm using an AC stick welder and the amperage setting was between 90-105. The rods are 1/8". I was welding 1/4" steel.
Any ideas?
-RC
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Post by rsmith on Dec 5, 2007 7:56:09 GMT -5
The "E" on the rod stands for electric or electrode so that is no concern. I am not sure what the 1 means. It has been my experience with a 7018 that it behaves better on a DC machine and a certain polarity. I can't remember which polarity. I just switch it around until it sounds right. We always used 6013 or 6010 (overhead) rods on the farm, because they were best suited for our AC machine. However, since I have gotten my DC welder, I usually do my initial weld with a 6013 and top it off with a 7018. Has 7018's worked well in the past on your AC machine? This is just my "plowboy" observation. I will ask Bobby when he gets here in a while what he thinks the problem is. He will pinpoint your problem. BTW, Bobby's Metal Trades class just earned national certification and recognition.  |
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Post by rsmith on Dec 5, 2007 8:33:58 GMT -5
Here is what Bobby said:
They probably handed you some 7018 DC rods. They usually work best on reverse polarity on a DC machine. He is not sure what the "-1" on the end of the rod means. That is usually a manufacturing code and you will have to look up the specific manufacturer to determine what that means. It could mean that it is a DC rod. AC 7018's are becoming a rarity and chances are if they pulled them out of a big box then they were DC rods.
If you know for sure that they are AC rods and the splattering is occurring then moisture is to blame. If no one in your house will fuss at you, then you could cook them a while in the oven to help remove the moisture.
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Post by rccolacc on Dec 5, 2007 9:27:43 GMT -5
If no one in your house will fuss at you, then you could cook them a while in the oven to help remove the moisture. That crossed my mind. I live alone in my house so no one will fuss at me. I don't even own oven mitts-- I use the welding gloves. Thanks for the response. I'll go by the NexAir place today and see what he says. I bet they are DC electrodes though. They didn't sound right when I struck the arc. Tell Bobby I said hey. Word has it he was here at Taylor a few weeks ago. I was talking to Joe Cowart here at work and Joe was saying he saw Bobby here taking a tour. Is your class coming by again anytime soon? -RC |
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Post by rccolacc on Dec 6, 2007 15:46:22 GMT -5
Ok the NexAir guy says that the 7018s he gave me were DC rods. The AC version of the 7018s are not common and are more expensive, therefore you should always ask for them by name. My fault for not checking that when I bought them.
That explains it all pretty much. I can return them so it's no big deal.
-RC
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Post by rccolacc on Dec 6, 2007 15:48:48 GMT -5
By the way I have used 7018s on the AC machine before in the past, but I've always purchased them at Lowes. The ones that are prepackaged at Lowes are both AC and DC electrodes, FWIW.
-RC
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Post by broncocraigellis on Dec 7, 2007 23:03:06 GMT -5
Thanks for the info. RC...on a side note, do you guys have any experience welding cast iron (gray)? I've read info. on Lincoln's website and on pirate, but I'd love to hear actual experience. Here's the process I've heard for welding mild steel to gray cast iron:
1. 99% or 55% nickel rod
2. evenly preheat casting to 600-1000 degrees
3. weld in 1" increments all in the same direction
4. wrap with insulation or bury casting in sand and allow to cool very slowly
The way I understood it, the cast iron does not like to shrink and swell...instead of bending it cracks if it rapidly changes temperature. Hence wrapping the casting after welding to allow the HAZ from the weld to cool at the same rate as the rest of the preheated casting. Otherwise, the casting would shrink as the HAZ cooled, thereby causing cracks.
Sound right??? Am I missing anything?
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