Welding tips

[idosubaru]

I need to repair the frame on my tractor.

 

When welding two plates of steel together, meaning one end to another, do you butt them up next to each other or leave a small gap and fill that gap with weld? How wide should that gap be? Probably 1/8" - 1/4" steel.

 

And should I just match the thickness or should I make the piece I'm welding into the tractor frame a little thicker to give more metal to weld too?

[lostinthe202]

There are certainly more experienced welders on here then I, but I don't think you want a gap but rather to chamfer the ends of both plates to create a nice thick "V" shape that you fill with weld.

 

I would think that matching thickness would be the ticket. You're only as strong as your largest cross section of steel so having one thicker won't do you any good.

 

Hopefully you've got good access to clean up the area in question really well, like all paint removed, all oil and grease gone, bright metal showing.

 

Good luck!

 

Will-

[hatchsub]

There are certainly more experienced welders on here then I, but I don't think you want a gap but rather to chamfer the ends of both plates to create a nice thick "V" shape that you fill with weld.

 

I would think that matching thickness would be the ticket. You're only as strong as your largest cross section of steel so having one thicker won't do you any good.

 

Hopefully you've got good access to clean up the area in question really well, like all paint removed, all oil and grease gone, bright metal showing.

 

Good luck!

 

Will-

Very good advice. Ive taken a welding course in the past and that is exactly the way you want to go about it. You want to clean all the grease/paint/debris off and make a nice v shaped area for the weld to penetrate down into. U do want them butted right up next to eachother with this v shapped channel. It should be plenty strong then. What are u using for a welder and how thick is this metal. If its 1/4 or over i would recommend stick welding it.

[idosubaru]

okay, great. thanks guys. access is easy enough to clean and put an angle on the edges. i'm welding in a complete rectangle all the way around so I'm not sure how tight i'll be able to get that, but i'll try.

 

it's probably 1/8" and all i have is a wire feed mig welder. i'll give it a try, if it doesn't hold i'll do it different next time. glad you mention that though, i'll be sure to keep templates of the repair for the next time just in case.

 

i'll be bolting a backing plate behind all of the "bad" metal that's torn out. once that plate is bolted in place behind the bad section, i'll weld the new piece of metal in place. so the welded piece won't be standing alone so to speak. actually the backing plate should be taking most of the load since it's spread over a wider area and that's what the bracket that holds some equipment bolts too and pulls against.

 

i might follow up with a picture here once i get the backing plate in place if i have any questions. thanks again!

[MilesFox]

it's been a while since i took welding class, but you will want to make your first bead to join the parts together, and then overlap your beads on each side to both pieces of metal. you can build up and fill in with multiple overlapping beads.

 

a stick welder would be best for this type of welding.

 

placement of the ground will determine how your weld will penetrate, depending on if you ground the existing frame, or ground the new metal. with a stick setup, you can do reverse polarity as well. sorry i am not knowledgeable enough to explain further. all of my experience is with crappy flux core welders.

 

make sure you get a nice puddle going before advancing you beads, and push the electrode into the direction of the weld, with small circular or back and forth motions to keep the puddle fluid.

[3eyedwagon]

202 is right about fitting a piece tightly, and beveling the edges. You want to basically make a nice V for your new weld to "lay" into. As far as using a wire feed welder; that is fine. There is no "best" equipment for this job. It could be done with stick, mig, tig, or even gas. A stick welder offers no advantage over mig other than portability.

 

Start by tacking the pieces together in multiple places. A good tack here, and a good tack there. Go about it methodically. That will help prevent as much distortion as you can. You don't want to start a weld only to get to the other end and see your plate has moved 3/4" from all the heat you're pouring into it.

 

I'm not sure as to what kind of wire feed wire you're using, but, in the event you are using hardwire with 75/25 mix gas shielding; you are really going to need to be picky about cleaning things correctly. Hardwire just isn't friendly with dirt or grease. Flux cored or dual shield will burn through crap a little more efficiently.

[GeneralDisorder]

If you are using flux-core, remember to clean the slag off between weld beads to prevent slag-inclusion in the next pass.

 

If you can get hold of one, this sounds like a job for a stick welder. A larger MIG machine (220v) could handle it, but a small one will make for a lot of work and multiple passes on 1/4" plate. 1/8" would be the limit that I would weld with a 110v MIG machine as the number of passes would become tiresome and quickly eat up the duty cycle of most machines in that size range.

 

If this is a load-bearing component - it might require an annealing step with a torch to prevent cracking from the inherent stresses created in the metal from the welding process. Welding will cause localized hardening and will warp and stress the steel. These can easily lead to cracking down the line if there is flex in that area. Heating the entire welded area and several inches beyond with an oxy-torch and then allowing it to cool slowely will releive the stress and prevent such problems.

 

GD

Edited April 14, 2010 by GeneralDisorder

[3eyedwagon]

If you are using flux-core, remember to clean the slag off between weld beads to prevent slag-inclusion in the next pass.

 

If you can get hold of one, this sounds like a job for a stick welder. A larger MIG machine (220v) could handle it, but a small one will make for a lot of work and multiple passes on 1/4" plate. 1/8" would be the limit that I would weld with a 110v MIG machine as the number of passes would become tiresome and quickly eat up the duty cycle of most machines in that size range.

 

GD

 

Some good tips, but, I just don't know where you keep getting this silly info about a 110 machine not being capable of 1/4" plate. Even with hard wire, and some simple cleaning it is EASILY doable. And I have NO idea why you keep talking about multiple passes. They just aren't necessary. Especially since we are talking about beveling the plate. I've welded far more with far less, it just takes some common sense and prep work. As far as the duty cycle; 20% at 21V is standard for pretty much any modern 110v machine. Unless you have some Harbor Freight POS, and then that is just on you for having bought that pile, and in all honesty; anyone who was silly enough to consider one of those a viable option when purchasing a welder shouldn't really be giving welding advice. 2 minutes of continuous welding is ALOT. Far more than people realize. You'd be hard pressed to find anyone around here capable of doing such. The reality is this project is going to be tack, tack, tack, short weld, take a break, weld some more. 2 minutes of 21v is plenty to get this job done. Would more power be better? Yes, it always is, but, the idea you have that these 110 machines won't do that work is just wrong. Also, as I stated earlier; a stick machine would pose no better results. Especially since there aren't alot of people out there that can run 7018, or 6010 vertical or overhead. The only benefit of stick would be portability due to the leads. If it has tons more power, great; you won't need it. The tractor has wheels, so I'd drive it up to the mig machine personally.

Edited April 15, 2010 by 3eyedwagon

[idosubaru]

Doesn't need to be an argument, you guys are allowed to disagree. Thanks for replying 3 eye, this isn't that structural of a part so I'm not too worried about it - that extra confidence makes me more ready to jump on this. And I can always re-do it later!

 

It's not a harbor freight but not a lincoln either, I forget what it is but it does seem very hard to get a good weld with. I'm not a good welder, but I don't think it's all skill.

[GeneralDisorder]

Some good tips, but, I just don't know where you keep getting this silly info about a 110 machine not being capable of 1/4" plate. Even with hard wire, and some simple cleaning it is EASILY doable. And I have NO idea why you keep talking about multiple passes. They just aren't necessary. Especially since we are talking about beveling the plate. I've welded far more with far less, it just takes some common sense and prep work.

 

You are probably right with regard to a decent quality 110v machine - especially some of the "super" 110's. Sadly there's a lot more cheapies out there than we would like to see. I agree that it's doable - I just don't agree that it's something I would tell a newbie to do with a cheap 110 machine. I don't think Gary would get the penetration with it that he wants. But as he says - he can redo it . The more power you have, the easier it will be for someone with little experience to produce a strong weld (it might still be ugly as sin - but the extra amps will make sure it's ugly and strong too).

 

As far as the duty cycle; 20% at 21V is standard for pretty much any modern 110v machine. Unless you have some Harbor Freight POS, and then that is just on you for having bought that pile, and in all honesty; anyone who was silly enough to consider one of those a viable option when purchasing a welder shouldn't really be giving welding advice.

 

I do have an HF 110v machine - it was my first welder. Since then I've outgrown it and have used other, better 110's. I've learned a lot and studied under a master welder for several years. But I'm no expert - just relating my experience. Actually the little HF machine is decent - there are ways to upgrade it since it is so simplistic internally. It wins no awards for power, but it does the job - it sticks metal together and does it for a lot less $ than my big $$$$ model. It just tends to take more skill to run a smaller machine - especially a cheap smaller machine. It's a level of frustration that an inexperienced welder should avoid IMO.

 

2 minutes of continuous welding is ALOT. Far more than people realize. You'd be hard pressed to find anyone around here capable of doing such. The reality is this project is going to be tack, tack, tack, short weld, take a break, weld some more. 2 minutes of 21v is plenty to get this job done.

 

I'm sure you are right. I've just found that I hit the duty cycle limit on a lot of the cheap 110's I've used fairly often. I've hit it on my big Thermal-Arc too - but it takes a bunch of welding to do that. I like to setup my welding jobs so I don't have much in the way of breaks - I want to get it done and put the thing away. That tendancy probably leads to me hitting the limit more often.

 

Would more power be better? Yes, it always is, but, the idea you have that these 110 machines won't do that work is just wrong. Also, as I stated earlier; a stick machine would pose no better results. Especially since there aren't alot of people out there that can run 7018, or 6010 vertical or overhead. The only benefit of stick would be portability due to the leads. If it has tons more power, great; you won't need it. The tractor has wheels, so I'd drive it up to the mig machine personally.

 

Right again - I merely mentioned stick because it is often the case that stick welders in much higher output can be had for almost nothing used. The old Lincoln tombstone's are usually in the $50 to $75 range and can easily handle more than any 110 MIG machine ever built. I still subscribe to the notion that people should learn stick first. I didn't, but I had to go back and learn it and I'm glad I did. I don't use it very often because it's not convienent for me but it's there and the skills learned are helpful in all types of welding.

 

GD

[idosubaru]

I'm entertaining a significant bolt on repair too. I'll still weld a piece into the torn spot, but I'm hoping the bolt in affair will beef it up to make sure it never happens again. It was repaired once before, doesn't look like a good repair......but mine probably won't either. :lol:

[idosubaru]

success. the Kubota has been back to work for a few weeks now. welding went fine. glad you guys told me to bevel it, looking back i would have beveled it more. i welded metal back in place and cut a steel backing plate to bolt to behind it as well which will carry most of the load, so i'll never have to touch it again.

 

thanks to all!

[GeneralDisorder]

Glad it worked out for you Gary. Now you are a little closer to being a weldor .

 

GD

[idosubaru]

Glad it worked out for you Gary. Now you are a little closer to being a weldor .

 

GD

Ha ha, I'll assume that typo is intentional? I'm still below beginner level but the thicker steel is much easier to weld with my little welder than really thin sheet metal/exhaust stuff. I feel much more confident and would certainly do a better job the second time around if needed.

[GeneralDisorder]

Actually - true "aficionado's" of the welding arts refer to the *machine* as a welder, and the person running the machine as the "Weldor".

 

Yes - thick is easier. Sheet metal and exhaust are both tricky - one because it's thin and the other because it's thin and usually also pretty dirty .

 

For thin stuff, straight CO2 and .023 wire are a great combination. It's ironic that most people that buy the small, inexpensive 110v MIG's wish to do that kind of work but it's really not well suited to it unless you change the wire and add gas capability. Very frustrating otherwise.

 

GD

[3eyedwagon]

Actually - true "aficionado's" of the welding arts refer to the *machine* as a welder, and the person running the machine as the "Weldor".

 

 

GD

 

110% correct. A welder is a machine. A weldor is a person with a skill.

[DrSalt]

For thin stuff, straight CO2 and .023 wire are a great combination. It's ironic that most people that buy the small, inexpensive 110v MIG's wish to do that kind of work but it's really not well suited to it unless you change the wire and add gas capability. Very frustrating otherwise.

 

GD

 

I welded up 2 1/4 inch exhaust on my mustang with an old Arc welder, just had to buy some thin rod (that hadn't been left out in a shed for 20 years). Not a point and shoot operation like a good gas MIG setup but the results are pretty durable. Tip: do a few practice beads before starting on your project LOL