American Welding Society Forum
i am not a professsional welder. i am a farmer who makes most of his implements. i have bought several batches of 7018 rods over the past few years and have had repeated troubles with them (the counter guys at the welding supply store keep pushing them). i either have tremendous difficulty restarting them or they become a red burning inferno after i get about half way through the rod. i only have a little lincoln "buzz box" that welds a.c. i have been given the explanation that the 7018 is a d.c. rod. i bought that until i read on a chart that it isn't. for general 1/4" steel welding, should i just stick to the 6011 or what am i doing wrong?
Welcome to the forum! This is a great place to ask for help. There is a 7018AC rod just for AC machines.
Your local welding dealer should be more helpful. Explain the type of equipment you have and they will be able to steer you in the right direction and should have plenty of advise when it comes to selecting different rods for farm applications.
Your complaints are not unusual. Restarting 7018 is often difficult, the wire burns up inside the flux coating and doesn't touch when you try to restart. Scratching the rod on something rough (like a stone) to even up the end before you restart helps. If you tap the rod on the work instead of scratching it it works better for me. I've seen some pros who just don't restart a rod, just get a new one. Usually they haven't bought the rods themselves though. 7018 likes to be run hot and it will tempt you to overdo it. Not hard to wind up with red hot stubs. I doubt that you are keeping those unused rods in an oven the way the book says. The humidity from the air makes everything worse and also defeats the low hydrogen property of the rods. As stated above there are 7018 rods optimized for AC use. If you are not using high strength steel there is not a lot of advantage to be gained from 7018.
In the end a weld that is well made with 6011 is probably going to be stronger than one that is poorly done with 7018.
Another thought on restarting the 7018 is to (with gloved hand) pinch off the end of the rod before trying to scratch start it again. I don't mean to take all the coating off, just a pinch to get the end of the electrode closer to the end. This helps me with restarting the so-called lincoln "drag" rod 7028 too.
I too am a farmer that has been repairing and making my own stuff for quite a while. From what I've read, and someone please correct me if I am wrong, here is a general breakdown of the most common rods and their purpose....
70 series rods mean 70,000 psi tensile strength (7014, 7018, 7018AC)
60 series rods mean 60,000 psi tensile strength (6011, 6013 etc)
6011 rods are easy to use and work best on equipment that is dirty, rusty, oily, etc.
6013 easy to use, great looking welds, for clean surfaces. (tip this rod can be drug across the surface as you weld)
7014 the book I have says this is a good rod for sheet metal. I haven't used any in a long time so I can't really say much from experience. I am going to get some today for use on thin wall tube though...just to see.
7018 a low hydrogen rod, good looking welds (except I get a lot of spatter with them) a lot of people use them, they are used in structural seel etc,rods very susceptible to moisture damage (see post below welding w/6013 vs 7018)
Personally, I love the 6013 rods, use them all of the time. Try them next time you buy. I'll bet you like them too, just clean the surfaces to be welded best you can with a grinder. On dirty stuff that you can't get to to clean stick with the 6011. If you don't already have some, get a couple of those plastic tubes with the rubber seal to keep your rods in.
There are other rods, but I don't have any experience with them except for the cast iron rods and that's a story in it's self. :)
SteelDet is right about the ease of use of 6013 electrodes, we use them for general maintenance around the shop and for low amperage welding thin sheet metal. For me, the 7014's are the easiest rod to run and I like the higher deposition rate. The heavier slag is self lifting and the weld bead has a very smooth appearance. (almost no prep for painting)
Some of the dealers in my area carry Forney brand rods. They have a big assortment of rods including hardfacing and cast iron. In addition to the 25, 10, & 5 lb. boxes, they have 1 lb. boxes so you can try them out without spending too much.
Another easy to run rod is the 7024. You can just make contact and watch it burn. We use them to get the guys that are just starting to weld, excited about welding. Then we let em' have the rod with the "magnet in the end" if their head gets too big too quick.
The best thing to remember about 7018 rods is that they run best on machines with a high open circuit voltage. The little buzz boxes (AC or DC) force you to turn up the amperage to compensate for the low voltage. Usually the result is a glowing welding rod that falls apart before it should.
It is not that the rods won't work at all on AC or with the buzz boxes. It's just that they run best on the right welding machine. I recommend sticking (no pun intended) to the rods that are made for AC machines. because it will be a lot easier to make a good weld. And when you are comfortable with what you are doing, you will do your best work.
Maybe the next time you are at the welding store, the counter guys can give you a demonstration on 7018 welded with a buzzbox? That might prove interesting.
It's true that with your machine the limited OCV will make starting and maintaining an arc with a regular 7018 very difficult. However, there are other versions of 7018 which are specifically designed to work with these machines. Try Lincoln's 7018-AC, or Hobart's 18AC. They'll work on DC of either polarity or AC.
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