Precautions while welding on tractor

[CrosbyFamilyFarm]

I've got a number of repairs to make on my 1973 Ford 3550. The both the backhoe and fel have cracks in them. I am a novice welder, just starting out with a Lincoln 140 MIG welder.

What precautions should I make to not damage my tractors electrical or anything else? Should I remove the bucket first? I plan on angle grinding around the cracks in order to bring it to raw metal. Anything else I should do?

 

[kennyd]

Your '73 won't have any electronics on it to worry about, so just make sure the ground lead is close to the welding area so your not drawing current though bearings or bushings. But, a little 140 MIG (your using gas right?) may not be up to the task.

 

[CNC Dan]

Your '73 won't have any electronics on it to worry about, so just make sure the ground lead is close to the welding area so your not drawing current though bearings or bushings. But, a little 140 MIG (your using gas right?) may not be up to the task.

And as well as grinding off the paint, grind out the crack to thin out where you will weld to get good penatration. Preheating with a torch will help make the most of limited power. A bigger welder would have a better chance of success on the first try.

 

[muddstopper]

I will agree the little 140 amp mig might not be the right tool for the job. Especially for a novice. Grinding off the paint most likely isnt going to be sufficient grinding to get the job done, even with a bigger welder. I would turn your grinding disc up on edge and Vee those cracks out to make sure you can get a good root pass that penetrates all the way to the back side of the weld and make multiple weld passes to fill the Vee back to flush. With your first weld pass, stick to filling in the bottom of the root weaving side to side to tie the metal together. Second weld pass, weld from metal to center of first weld, again weaving side to side. Third pass, weld opposite side of metal back to the center of first weld pass, using weave. Third pass would be considered a cover pass and you would weave from out side edge of second pass to outside edge of third pass, this should tie all three welds together as well as the metal being welded. This might be the best you can hope for with the small mig and if you have a oxy/acet torch, a little preheat before the first root weld wouldnt hurt.

Better welders might have better advice, but that is how I would do it if it was mine.

 

[CrosbyFamilyFarm]

I do have an oxy/acetylene torch and will preheat before the first weld.

Would it be prudent at all to bolt a steel plate across the crack and weld that to the bucket or am I just trying to make a mess out of a simple crack?

And what would be the ideal welding unit to use on a job like this? Again, I'm a novice for sure.

 

[kennyd]

Showing some pictures of what your trying to fix would be very helpful.

 

[CrosbyFamilyFarm]

I will post them tonight.

Here are the pictures of the backhoe bucket crack.

 

[firemanmike69]

<img src="http://www.tractorbynet.com/forums/files/welding/441948-precautions-while-welding-tractor-img_5065-jpg"/><img src="http://www.tractorbynet.com/forums/files/welding/441947-precautions-while-welding-tractor-img_5064-jpg"/>I will post them tonight. Here are the pictures of the backhoe bucket crack.

Looks like someone has already been there a few times before you and yet the crack keeps coming back. I would be looking for the root cause: bucket lip worn thin, abusing the bucket, poor welding etc. Your welder isn't up to the task, plain and simple, unless that bucket is pretty thin and then that is likely the reason they bucket continues to crack

 

[Shield Arc]

I've only been welding a few weeks now. But I think the first thing I would do, is drill a hole at the end of each crack.

 

[RoyJackson]

I've only been welding a few weeks now. But I think the first thing I would do, is drill a hole at the end of each crack.

I agree...stop drilling should end the propagation...and definitely do bevel the crack for best penetration.