welding advice

[terry274]

I am making a bumper for my tractor. (Super Dexta) I need to weld some flat metal, 3/8 inch and 1/2 inch thick iron. The metal is from the frame of an old bush hog. What size and type rod would be best? Where should I start the amperage? I will be using a Lincoln AC welder, most of the welds will be done with the bumper laying horizontal on the ground.
Thanks, Terry

 

[Rick L.]

(quoted from post at 00:29:30 08/19/09) I am making a bumper for my tractor. (Super Dexta) I need to weld some flat metal, 3/8 inch and 1/2 inch thick iron. The metal is from the frame of an old bush hog. What size and type rod would be best? Where should I start the amperage? I will be using a Lincoln AC welder, most of the welds will be done with the bumper laying horizontal on the ground.
Thanks, Terry

first off get some scrap pieces and try your rod and heat setting. 1/8" 7018 works pretty well for me. set your welder around 80 to 100 amps to start and go from there. rick

 

[Greyhorse]

Make sure you get 7018 AC rod, if it isn't AC specific it won't work on your machine, you can also use 6013 or 6011 but 7018 is what most people like to use, I also like 6013. You can probably run hotter than 100 amps with 1/8" 7018 0n that thickness of metal but I would also recommend a practice run on some scrap of similar or same thickness. Make sure you clean everything up real good first, it'll go a lot easier.

 

[trucker40]

If you can get it to where all of your welds are flat you could use 7024.You want to grind everywhere you are going to weld.On the 1/2 thick stuff and even the 3/8 you want to bevel it if you use 1/8 inch rod.Tack with 6011,maybe even run a root pass with 6011,grind all the slag off.Then put about 2 or 3 passes of 7018 or 7024.In the case of 7024 you need to chip all of the slag off between each pass.If you know how to weld with 7018 you can get away without chipping it on the second pass.May need to chip it for 3rd pass if needed.I would use 1/8 rod at about 90-120 amps.If you get it set right and run it right 7024 will peel the slag off as it cools.7024 has to be clean because any little bit of slag,rust,dirt,grease will mess it up.That stuff is not good for any weld,but 6011 will burn through a lot.7018 would be the strongest weld if done right.7024 is strong,easy to weld with as long as you weld flat or horizontal and looks good when done right.
When you weld something like a 1/2 inch thick piece of metal your weld needs to be 1/2 inch wide.So if you make a pass with 1/8 rod and have a 1/4 inch wide weld,you need to weld another pass beside that one to get your 1/2 inch wide weld.Now if you are welding a 1/2 inch piece on top of another 1/2 inch piece and the weld is horizontal you need to build it up.The way you do that is weld a pass that sticks the 2 together,chip grind whatever it takes to get it clean,run another pass next to that one,clean,run a pass on top of that one,and maybe run a pass on top of that one.When you get done you want a weld that comes out about 1/2 inch at the base and goes all the way to the top of the metal you are welding 1/2 inch up.If you were welding something thicker like 3/4 you would run 3 or 4 passes starting from the bottom again up to the top.I have made welds that were 6 inches wide before,one on top of the other all day long for weeks at a time.Had to be x-rayed when done and could not have any slag in them.Anywhere that wouldnt pass had to be cut out with an air arc,ground and welded and x-rayed again.It only takes about one night of running an air arc and grinder and you learn to get all the slag off of your weld.We had real big rods and big machines to burn them,but its done the same way.
With your 3/8 and 1/2 inch thick metal you need 2 passes minimum and 3 on the 1/2 probably.
I looked at answers on Google and it said to weave your weld,but I can tell you from experience that building up stringers is best.Sometimes you can weave.Especially uphill,but its not too good to weave 7024 because it might crack.7018 maybe,but it is probably best to build it up.If you dont know how to weld there is a little bit on you tube that shows how.It would be better for somebody to show you how to use whatever rod you get so you get started on the right track and make welds that hold.

 

[trucker40]

You do not want to weld a bumper for your tractor with 6013.6013 is for sheetmetal not 3/8 or 1/2 inch thick steel.Somebody thats a good welder might be able to weld with that but there are way better rods than that stuff.6013 is for people who sell rods not people that weld.Its mild penetration,not what you want for a bumper and not as strong as 7018 or 7024 or even 6011.You could weld it all together with 6011 one pass and it would be way stronger than if you welded it with 3 passes of 6013.

 

[Tim Casbolt]

If you're welding steel to iron, I'm not sure 7018 is the way to go. Might want to check at the local welding store for a recommendation.

 

[Stan in Oly, WA]

Hi Tim,

Good catch. My guess, though, is that the word iron is used in its idomatic sense here, the way cement is often used for concrete. Angle iron and black iron pipe are familiar names of products which are made of steel.

Actual iron would seem a poor choice for a bumper (not to mention for the frame of a piece of equipment that sees some rough service) but I've been known to be mistaken. 7018 isn't necessarily a bad choice for welding iron to steel but it requires a tedious technique, and more attention to temperatures than most people are willing, or able, to undertake.

All the best, Stan

 

[bc]

What are you going to push or hit with that bumper? I'd think about bolting on a treated 4x4 timber. Need rubber? cut an notch out an old tire to lay on the front of it. If you drive your tractor into the side of the barn, maybe the timber will break before you do much damage.

 

[TomTex]

Exactly what are you calling "iron"? Are you refering to plain ole mild steel? Tom

 

[terry274]

Yes, I believe the metal is mild steel.

 

[Anonymous-0]

I would do some easier projects first.A bumper has some bends that must be accurate.