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.

 

[muddstopper]

Lot of weld already been laid on that bucket. Cant say much about the quality of the weld from pics, but it aint looking good. I am guessing the weld was just laid down on top of the metal without proper grinding. I would forget using the 140am mig and look for someone that has a 200+amp mig or a good stick welder to fix the crack. I would also drill the end of the crack, but certianly grind a good vee along the crack and then weld it up with multiple passes as I already described. I would also ping the weld with a hammer after each pass with the welder to take out some of the stress of the metal heating up and cooling off.

 

[Jorville]

View attachment 441948View attachment 441947I will post them tonight.

Here are the pictures of the backhoe bucket crack.

Those pictures show the crack at the high wear area of the bucket. The steel the teeth are welded to is not just mild steel like the rest of the bucket. The way I would do it is to vee out the crack. preheat the area to 400 degrees Fahrenheit and weld with 7018 electrode. And maintain the 400 degrees while welding. after it has cooled I would vee out the other side and repeat the process. As others have said, the welder you have is not the one for this job.

 

[CNC Dan]

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 just saw the pics, and came to the same conclusion.
And it may be hard to see the real end of the crack. Grinding the surface beyond where the crack seems to end, then applying some acetone, and wipeing the surface dry, may reveal the true end of the crack. There are kits that are made for crack detection that may work better.

 

[harlow89]

I agree that the welder is not up to the task. but for the best chance at proper penetration I would groove the crack on top and bottom and pre heat to a pretty high temp. I would also run the welder as hot as it can possibly go. but the next problem you will have is that you will most likely duty cycle the welder. When that happens make sure to put some more heat in it before you resume welding. good luck!!

 

[muddstopper]

Interesting that a temp of 400*F was mentioned for preheat. I like to use a propane weed burner and always try to get around 800*F when I preheat. Not sure why, probably because I read somewhere 600*F-800*F for preheating, But I might have dreamed that too. One of you pros want to say whats a proper preheat temp?

 

[muddstopper]

Interesting that a temp of 400*F was mentioned for preheat. I like to use a propane weed burner and always try to get around 800*F when I preheat. Not sure why, probably because I read somewhere 600*F-800*F for preheating, But I might have dreamed that too. One of you pros want to say whats a proper preheat temp?

A quick search found this;
Preheating Ferrous Metal for Welding
What is Preheat?
http://www.bocworldofwelding.com.au...brary-Preheating of materials-Consumables.pdf
And this one for cast iron, Guidelines for Welding Cast Iron

I guess I have been preheating a little hot, but it has worked for me. I do like the propane torch for perheating better than oxy/acet because it does heat a much wider area, and faster, than i can with the oxy/acet torch, and it cheaper than buying other gases.

 

[CrosbyFamilyFarm]

So what I've gathered is the following:

I don't have the right welder for the job.
A stick welder or 200+am mig welder would be the right tool.
I should ensure that when I do weld, I Vee notch the crack to ensure a proper weld.

Again. I'm a novice so sarcasm and jokes go right over my head. Whats everyone talking (joking?) about with the drilling of holes business? I couldn't tell because the winking face threw me off.

Can anyone suggest an affordable stick welder that would be appropriate for this job?

 

[k0ua]

So what I've gathered is the following:

I don't have the right welder for the job.
A stick welder or 200+am mig welder would be the right tool.
I should ensure that when I do weld, I Vee notch the crack to ensure a proper weld.

Again. I'm a novice so sarcasm and jokes go right over my head. Whats everyone talking (joking?) about with the drilling of holes business? I couldn't tell because the winking face threw me off.

Can anyone suggest an affordable stick welder that would be appropriate for this job?

They weren't kidding about drilling a hole at the end of the crack. This is a well known and practiced method of stopping crack propagation. It is used in metal, and even plastic like aircraft canopy's. I have seen several done in canopy's.

My little Everlast would make short work of that problem with proper prep.
Check out this crack problem in my old Kubota bucket.

http://www.tractorbynet.com/forums/welding/249487-oh-no-my-bucket-broken.html?highlight=

 

[flusher]

"Can anyone suggest an affordable stick welder that would be appropriate for this job?"

Hobart Stickmate LX AC/DC (220 VAC) stick welder. $500 or so at Tractor Supply.

Hobart Stickmate LX 235 AC/160 DC Stick Welder - For Life Out Here

If you've never stick welded, there's a learning curve that will take a while. Rule of thumb: you need to burn a 100 lb of stick to get proficient. Since you have MIG experience, learning stick should go a bit faster.

Good luck

 

[k0ua]

Here is the Everlast site. If you contact Mark here on this forum you can usually get a discount.