What's better to weld C-notch: ARC or MIG?

[TIMSPEED]

A friend and I had a debate about this...
He said that ARC welding would destroy my frame, if I tried to weld on my C-notch with my ARC welder. My arguement was that with a MIG welder, it wouldn't be strong enough to not worry about.
What's a better way? (Not considering price or skill of welder)
I was considering just popping on the C-notch and then running a bead between the edge of it and the frame, with my ARC welder. (Using the correct temp/rod of course.)

[lost wages]

arc is good if the frame is dirty or rusty, if you grind everything clean a mig will be a nicer looking weld, My father has a steel fabrication shop and builds small bridges and everything else with a mig, plenty strong if you got the right welder, i would use a 1/2 inch machine so you have plenty of heat.

[Tx Firefighter]

Plenty of frames have welds from the factory done with MIG welders.

I've welded on lots of front crossmembers to frames with my MIG welder. Every street rod out there pretty much gets a new front crossmember, and damn near every one of them is MIGed on.

It really depends if you have a powerful enough unit. People think MIG is the little machine you buy at Home Depot. They make them all the way to heavy industrial units too.

[N2TRUX]

I would feel much safer using a MIG welder on a frame. If the welder knows what he is doing, he can get the heat down on an Arc welder and make it work. Just about any idiot can control the heat on a MIG. I have used my little cracker box MIG to weld 1/4" plate with a single pass. If you have a good power cord, even a small MIG can do the job...

[jamis]

either one will do, I did my c-notch with a stick welder because thats all I have at home, Stick welding has the advantage of diffrent types of rods for diffrent jobs, I like a 6011 or 8011 for the frame. You can weld under worse conditions with a stick then a mig. Always try to use fresh rods if you dont have an oven to keep them dry in.
All the smaller peices I do at work with a wire feed because its cleaner and easier. If a had an industial mig at home I would of used it on my frame as well. Put you need at least 200 to 250 amp mig to get good penatration on the heavier stuff like a frame.

[phantom dually]

I do work for a major frame builder that does all the light duty frames for Ford. They build the frame from start to finish. The only thing they use is a mig and .040 wire.

[67Fleetsidedream]

If you have a small MIG machine this is what you can do to get good penetration.....Grind the edges of the cuts on both sides and then weld the peices together....Just a TIP...

[Izzy]

I've used both ARC and MIG and they both work perfect for me.

[78chevstepside]

It makes no difference. Any welding process will work mig, stick, tig Its all in the filler wire. For example 60 series stick rod 6010 6011. 6o thousand pounds per square inch . 70 series rod 7018, 7011 70 thousands pounds per square inch tensile strength. 7018 would be your best stick rod to use on mild steel(mild carbon steel). If rusty or dirty 6010 would be a better choice( less strength ). Using a series higher then your 70 series wouldnt be recomended. 80 series is getting into a higher chromium 2% preheating may be required . and if you go to a 90 series 5% chrome preheating is required. your third number on stick rod is postion 1 good for all postions 2 flat and horizontal, 3 flat only. Your 4th number is aflux number. the first number is alway e for electrode. On other pocesses like tig your bare wire will have a number on it. example er70s2 this would be for mild steel 70 series. with any process when welding with mild steel 60 or 70 series filler material is your best choice. All iam saying you need to match your filler wire with the base metal. The frame on a truck is just plain old mild steel . They weld on the frames at the factory. Welding on a frame wont distroy it . With proper technic any process will make a nice looking satisfactory weld.

[wg77]

Originally posted by jamis If a had an industial mig at home I would of used it on my frame as well. Put you need at least 200 to 250 amp mig to get good penatration on the heavier stuff like a frame. [/B]

I think 200 to 250 amps will melt right through that truck frame,considering chevy frames are barely 3/16" thick in some places.My mig is rated for 150 amps and will undercut 3/8" plate at full power.

just wanted to add my 2cents.

[78chevstepside]

that would seem a little hot. Welding Machines are really not very accurate and may vary alot from machine to machine. What is great for one machine may not work well for another. Also your power coming into machines tends to fluxuate. this comes more into play when multiple machines are present. You know when its quiting time or lunch time your machine gets hotter. Using a welding machine for arc gouging messes them up over a long periiod of time. For smaw with 3/32 rod 7018 i like to run in the 80 to 90 amp range. For 1/8 7018 100 amps to 115 amps. You really have to go by sound and how easy the slag fall off the welds. Also looking to see how red your rod ( welding rod stub)is when it is consumed. If it melts off your stinger before you finish its a little hot(and if you have a stawberry patch OR and dingleberrys). This is more of a indication with 3/32. The slag should almost roll off The weld. If you got to beat it into submision with a slag hammer turn it up. At 250 amps you could almost or may very well use the rod as a torch. Personly I have used some machines(not by choice) that you have to run real hi amperage.