Stick or MIG on thick plate???

[JCC]

I would have either gone for a 250 amp class mig or a much (MUCH!) cheaper AC/DC stick welder. The learning curve for stick welding isn't very steep if you have already taught yourself what a good looking mig weld looks like.

You are right, I am just being stubborn about learning stick welding. And also about the 250 amp class MIG. Unfortunately they start at around $1500 which is more that I want/can spend. I figured I will tough it out with the 210A welder since other that this hoe project I will rarely need to weld up to 1/2".

 

[Army grunt]

I use a mig up to 1/4" An my buss box after that. I use both hands to steady an help guide them both.I am 65 age don't have anything to do with it. The proper setting is whats important with both.
Army Grunt

 

[kjung17]

The root gap not wider than filler metal only works for stick rod. You wont get full penetration with a mig with .030 or .045 gap. you need a minimum of 1/8" to get the penetration you need. We use 3/16 gap for tacking on larger pipe which sucks down to about 5/32 after it is all tacked up. Run it downhill and keep the wire feed pointed into the puddle. Takes some practice to keep the wire from porcupining inside but once you get the hang of it, it makes a nice weld. I know most of you think if it burns thru it is bad.

You sound like a welded/ boilermaker. Do you not have to repair burn through on the I.d.?

 

[Transit]

0.030 And 0.045 wire may be the wrong choices. What is wrong with 0.035 wires? At the higher amp settings and the proper unit you will get spray transfer, very hot puddle for fillets. For the root gap, I use the same mig wire to set the gap, very little burn through. Take the grinder, on edge and cut a U grove into the backside of the root to clean up and re-weld.

 

[Ford tractor]

You are right, I am just being stubborn about learning stick welding. And also about the 250 amp class MIG. Unfortunately they start at around $1500 which is more that I want/can spend. I figured I will tough it out with the 210A welder since other that this hoe project I will rarely need to weld up to 1/2".

:laughing: Sounds like me. (the stubborn part) You may want to sign up for a vo-tech evening class on welding. I took one and it was loads of very cheap fun. Plus you could bring in any projects you wanted and weld them up with the school's equipment, wire and rods WITH an expert looking over your shoulder. Made me a better welder (but still not a WELDER).

 

[bigdad]

Check this out from Miller. It's great.

Miller - Stick Welding Calculator

 

[Chilly807]

Check this out from Miller. It's great.

Miller - Stick Welding Calculator

Thanks for the link, I'll save that one !!

 

[Shield Arc]

Well I did some more research and decided to buy a Hobart Handler 210 MIG welder. Its rated up to 210A and 3/8" welds with one pass. That is a little short of 250A which is ideal for 1/2". If I bevel the plates, use a root gap and maybe pre-heat with multiple passes I think it should be fine.

JCC if you want to throw a little more power / penetration to your new Hobart Mig machine pick up a roll of .045 dual shield. A lot of dual shield you can run 75 % argon / 25 % Co2 gas or if you want even more penetration go with 100 % Co2.
I like ESAB's 710X. Here is a picture of some 710X .045 wire run vertical up with my little 200-amp Mig machine.

 

[evo803]

I got a Lincoln pro-mig 180 given to me by a friend for my tractor project that I am doing.This is my first welding project but I find 3/8" to be the limit for this welder to do work in a timely manner. Proper joint prep then 1 root and 2 cap passes is all it takes for me to get excellent penetration in 3/8" . If I had some 1/2" to weld on occasion I certainly would do it but, not a backhoe project.

 

[KWentling]

Man, I read some of these replies and I have to wonder how big of a welder some think they would need to weld 2" plate. (And how big of rod they would stick weld it with) At work, we have welders up to 1000 amps. That machine is used almost solely for air arcing now, used to sub arc with it. Most everything is now welded with dual shield 1/16, or .045. Machines are mostly 600 or 450 amp. We weld 16 gage to 2" plate all the time, and I personally have 4". Its just a matter of proper prep, preheat, and multiple passes. Maybe run off tabs. I have a Lincoln SP135 plus that I wouldn't hesitate to weld 1/2 plate with if I didn't have a 255 now. I think his 180 will work fine. The biggest mistakes I see people make is running their machines too cold, lack of joint/material prep, and no preheat. Pretty easy to make a nice looking weld that is just setting on top of scale. I doubt he is going to be doing much (maybe any) full penetration 1/2 plate in a backhoe. It will mostly be lap joints, and maybe 1/2 fillets. Nothing wrong with 3 passes if thats what it takes.

Kim