ARC welding pitting

[akrejci]

So I started to construct a go kart, and I joined this forum because I figured if I ran into any problems, this is where I could find help. Well I started to weld up the frame today, and I am using 1 1/4 inch square tubing with 1/8 inch wall. I have an arc welder, and this is the first time I will be welding tubing.

So I have no clue what the pitting is from. I cleaned the joints very well except for the inside of the tube lol. It wasn't raining, and like I had said, I have welded before. The only thing I could think of that would cause the pitting is the trapped air on the inside of the bar. Any help would be awesome.

 

[KieranM]

What type rod are you using?

Make sure that if you reweld over a weld you remove all the slag as you will get slag inclusion in your next weld.

Bare in mind it takes practise to weld arc without "Pits" or slag inclusion.
Also make sure rod has been stored inside at a suitable temperature.

Might also help to bevel the ends of the tubing for a better flow.

Other than that arc is hard to do perfect without years of practise.

And have no rust present on the steel your welding.

 

[machinist@large]

So I started to construct a go kart, and I joined this forum because I figured if I ran into any problems, this is where I could find help. Well I started to weld up the frame today, and I am using 1 1/4 inch square tubing with 1/8 inch wall. I have an arc welder, and this is the first time I will be welding tubing.

So I have no clue what the pitting is from. I cleaned the joints very well except for the inside of the tube lol. It wasn't raining, and like I had said, I have welded before. The only thing I could think of that would cause the pitting is the trapped air on the inside of the bar. Any help would be awesome.

:toetap05: Looking at the 2nd photo, I'm guessing that you are referring to the pit at the upper R.H. end of the weld. I'm also guessing that is your start point for the bead. If so, then what you are looking at is called cold lap. Even though the tube may be thinner than the diameter of the welding rod, the tubes to be joined have more mass than the rod. This means that the rod comes up to welding temp. quicker than the tubes.


Basically, the end of the rod is fully molten while the tubes are still heating up. The filler matl. from the rod proceeds to lay down on the surface like a bead of frosting on a cake while the rest of the weld zone catches up and starts to fuse. This can happen to any of the common forms of arc welding (tig, stick, and most commonly mig/flux core). The lower the power setting, the more likely this can be a problem. While a lot of the newer, higher end welders have settings to help minimize it, the only way around it is practice, practice, practice. Mig is the worst because you can force a bead to form without any penetration, especially if there is a lot of scale or dirt present.


Hope this helps. Pat H.

 

[kendelrk]

what about heating up the tubes already with a propane torch and then taking and using the welding rod?

 

[akrejci]

I was using 6013 common rod at about 105 amperage. The pits tend to happen at the end of the weld, which makes me believe that the metal is heating up too much by the end of the weld, which causes heat sink in the metal. I tried to lower the amperage, and the weld had little penetration. I am going to re-weld tomorrow over the pits after I clean the hell out of the joints.

Subtopic: Who thinks I should reinforce the corners with angle steel? I know the welds loose strength when you grind them, but I figured there would not be enough flex in the frame itself to break a weld since it will have shocks.

 

[landuse]

I was using 6013 common rod at about 105 amperage. The pits tend to happen at the end of the weld, which makes me believe that the metal is heating up too much by the end of the weld, which causes heat sink in the metal. I tried to lower the amperage, and the weld had little penetration. I am going to re-weld tomorrow over the pits after I clean the hell out of the joints.

Subtopic: Who thinks I should reinforce the corners with angle steel? I know the welds loose strength when you grind them, but I figured there would not be enough flex in the frame itself to break a weld since it will have shocks.

There is no harm in putting some gussets in the corners to reinforce your frame. They will not add that much more weight to your frame, and it will give you the peace of mind that you frame is not going to break at the welds.

 

[ryf]

ugh, I have an arc welder and i have had nothing but problems with 6013 just being weird to weld with, 6011 worked much better for me. 7018 is a good DIY weld rod though 10,000 PSI stronger and even ugly welds are usually pretty strong. hope that helps anyway.

grabbed for example from <http://www.rodovens.com/welding_articles/welding_rods_application.htm>

6010 welding rods penetrate deeply but have high spatter. They are good for all positions, all types of steel, and almost any conditions and use DC current. (For better penetration on thicker steel over 3/8," bevel the edges and create a gap of about 1/8" wide; use 6010 for tack up and a root pass and weld the remaining passes and the "cap pass" with 7018.) 6010 welding rods need to be stored in a dry location, at room temperature, and in a sealed container.

6011 welding rods have all the characteristics of 6010, are used in all positions with AC or DC current, and work well on all types of regular or mild steel.

6013 has all the characteristics of 6010 but can be used with AC or DC current; it has less penetration and delivers a better-looking weld. Use 6013 on light sheet metal up to 3/16."

Use 7018 low-hy, low penetration, on all positions, with AC or DC current. Use the highest amp setting as practical. Use a straightforward "drag" progression with a "short arc." The low moisture make-up of this welding rod reduces chemical reactions in the weld itself and makes for the highest quality x-ray perfect welds. (Note - this electrode must be kept dry. If it's exposed to humid air or gets damp it must be dried in a rod oven before use. See Welding Rods Storage chart.)

Use 7024 high deposition welding rods for flat and horizontal positions. It's "easy" to use because its thick flux automatically maintains the correct arc length, which allows you to "drag" the rod.

 

[machinist@large]

I was using 6013 common rod at about 105 amperage. The pits tend to happen at the end of the weld, which makes me believe that the metal is heating up too much by the end of the weld, which causes heat sink in the metal. I tried to lower the amperage, and the weld had little penetration. I am going to re-weld tomorrow over the pits after I clean the hell out of the joints.

Subtopic: Who thinks I should reinforce the corners with angle steel? I know the welds loose strength when you grind them, but I figured there would not be enough flex in the frame itself to break a weld since it will have shocks.

6013 is an acceptable rod for what you are doing. Use the smallest dia. 'trode you can; it'll be less like trying to water a flower pot with a fire hose. All welding rod types have their quirks; it just takes time and practice to learn them. ryf's description of the different types of welding rod and their peculiarities barely scratches the surface on this subject; there are a lot of good books out there on this. One I can recommend for anyone is the "Forney Welding Manual". Many hardware and ag supply stores carry Forneys' products; if they don't have a copy on the shelf, they can order it. It's one of the best books I've found for good basic info, and it's written for the DYI'r; doesn't waist your time with descriptions of things most of us will never see in the field.

Small gussets are good; they don't have to be very heavy to add a lot of strength. Joint design is another topic that whole books have been written about. A good welding class would make many people writing on this forum's lives easier because they wouldn't be groping in the dark with their questions.

 

[ryf]

yeah its acceptable, I merely meant to point out there were other options that might be easier to work with. I do not personally like 6013 characteristics, its not impossible to use, nor is it "bad" it is IMO not the easiest to use if your a hobbyist welder, I like the 7018/6011 sticks because they, for me, have yielded way better results for me. as much as "what you have is fine" is true, it doesn't mean its the easiest way to get the job done. I have been hobby welding since the mid 90's and i am sure there are lots of books that could teach me more than I care to know but i like what I like and its 7018/6011 for me

 

[machinist@large]

yeah its acceptable, I merely meant to point out there were other options that might be easier to work with. I do not personally like 6013 characteristics, its not impossible to use, nor is it "bad" it is IMO not the easiest to use if your a hobbyist welder, I like the 7018/6011 sticks because they, for me, have yielded way better results for me. as much as "what you have is fine" is true, it doesn't mean its the easiest way to get the job done. I have been hobby welding since the mid 90's and i am sure there are lots of books that could teach me more than I care to know but i like what I like and its 7018/6011 for me

Looks like we're attacking this question from different angles but with the same target. I think one problem a lot of people have with stick welding is because they are trying to do to much with what they have on hand. Example; bought box of welding rod- only size store had (1/8 in.). Trying to weld thin matl. (say, 1/16 in.) using old tap type welder (20 +/- amps per step). All of these problems can be worked around if you know what you are doing. Our beginning weldors problem is that they don't have that experience, and are beating their heads against the wall because of it. The folks using HF mig welders set for flux core are in the same boat. And an on line welding class isn't.

 

[ryf]

agreed, I personally, if I had 6013 I would use it all and in general I dont care if its pretty as long as it penetrated and has the job done, I do find alot more trenches and pits with 6013 because it feels like it burns and fills at a different rate, and I have a hard time matching that sticks rhythm if you will, since I am more natural with other types I just buy them lool.

 

[machinist@large]

agreed, I personally, if I had 6013 I would use it all and in general I dont care if its pretty as long as it penetrated and has the job done, I do find alot more trenches and pits with 6013 because it feels like it burns and fills at a different rate, and I have a hard time matching that sticks rhythm if you will, since I am more natural with other types I just buy them lool.

Stick welding takes patience, that's all there is to it. One of my welding teachers once greeted my basic stick class with something along the lines of 'Welcome to industrial penmanship" because he told us that "Welding is longhand cursive written with a pencil that changes length as you write.":toetap05:

When we got out to the shop, that was topic A at the quenching tanks and the rod oven. When asked, all he would say was "Use you brain as well as your eyes".

To make a long story short, he was talking about patience; a proper weld is going to take the time that it takes. You can't rush it. That's what trips most people up.

 

[sexyvicta]

I just bought a stick welder thing last week.

I'm having exact same problem as you haha

I was using some small rods(cant remember which exactly) and they were quite easy to use and i was making ok welds but then i ran out of those, so I walked up to the hardware store and got some 6013 as that was the smallest/thinest looking ones they had. Now things are much harder and im geting that same pitting as you every time- im trying to weld up a bike frame lol. Less than ideal.

im thinking practise makes perfect. Try again

 

[machinist@large]

I just bought a stick welder thing last week.

I'm having exact same problem as you haha

I was using some small rods(cant remember which exactly) and they were quite easy to use and i was making ok welds but then i ran out of those, so I walked up to the hardware store and got some 6013 as that was the smallest/thinest looking ones they had. Now things are much harder and im geting that same pitting as you every time- im trying to weld up a bike frame lol. Less than ideal.

im thinking practise makes perfect. Try again

Don't get discouraged!! Did the first batch of rod come with the welder? Did you buy it from a welding distributor? If so, they should be able to tell you what came with the machine and (hopefully) provide you with more. Welding suppliers don't make much money on the machines; they make it selling the consumables; rod, wire, gasses, etc.

Stick welding isn't easy. Once you get the hang of it, though, you'll be surprised at what you can do with it. And think about penmanship; would you rather be remembered as the treaty writer, or the one with the doctors scribble?

 

[sexyvicta]

Don't get discouraged!! Did the first batch of rod come with the welder? Did you buy it from a welding distributor? If so, they should be able to tell you what came with the machine and (hopefully) provide you with more. Welding suppliers don't make much money on the machines; they make it selling the consumables; rod, wire, gasses, etc.

Stick welding isn't easy. Once you get the hang of it, though, you'll be surprised at what you can do with it. And think about penmanship; would you rather be remembered as the treaty writer, or the one with the doctors scribble?

haha yeh im not getting discouraged. Im only building this bike so i can learn to use this welder.

I didn't get any rods with the machine, i got it secondhand for $60(its not chinese either:arf. The rods i was using the first time were were 2.5 I think but the guy at my local hardware store ran out of those so i bought the 6013 which i think is 3.2?

iduno but yeh they are much harder to use on the bike frame than the ones i had before. Might goto a big hardware shop tmrw and see if they have a better selection.

 

[akrejci]

So I did some practice welding with the 6013 on some spare pieces of tubing and after 10 passes with all different settings, I finally found that I need to have a higher voltage with a longer arc and the welds look great with good heat penetration. ( I will post a picture later today hopefully)

I am probably going to weld up some gussets to the corners using some angle steel. Thanks for the info.

Anyone know where to find a good seat? I don't want to buy a new seat, I kinda want to make this a full diy kart. If I could find a jeep seat, would it fit? Open to any options.

 

[Bluethunder3320]

for a seat i would take a piece of plywood, bring it to wal-mart, and ask the sewing/fabric department if they have any padding and seat cover that you can staple on the back... then drill holes in the wood part and screw it into flanges or holes in the frame.

also off topic from the pitting, one way you could have made it stronger is if you cut both pieces 45 degrees and welded all the way around. also this leaves no open hole for water to get in and rust the frame inside out.

 

[devino246]

A little late but, 6013 rods are crap, IMO. I prefer to stick with 6011...

 

[machinist@large]

A little late but, 6013 rods are crap, IMO. I prefer to stick with 6011...

6013 rods were developed to fill a niche market; to be easy to weld with. It's one of the fast fill/ fast follow class of rods. used properly, it produces O.K.welds. Decent penetration, decent strength, decent appearance. A good handy man rod, but there is better.

6011 is the AC version of 6010. It's a fast freeze/ fast follow rod with excellent penetration. Works best on clean metal, but can burn thru a lot of crap. Nick named "Farmer Rod". takes more patience and skill to use. Because it's a fast freeze rod, it doesn't leave as pretty a bead. Ideal for vertical and overhead welding because it digs in and stays put till it freezes. (Solid metal is frozen metal).

Personally, I prefer 6010/6011 and 7018 for my all around work; just my preference. Personally, I don't think you can go wrong with 6011, Devino. If the slightly coarser appearance doesn't bug you (it does to some people), then keep on keepin' on.

 

[sexyvicta]

so what rod and setting would you recomend for welding bicycle frame tube?