Rods for welding cutting edge

[Jay4200]

I have a piece of town plow cutting edge that I plan to weld onto my bucket to make a new cutting edge. I am going to weld it directly to what little is left of the original welded cutting edge, placing the new material under the old then welding around the edges. The suggestion I have so far is to gap the new edge slightly below the old edge (like 1/16") to prevent cracking. Then burn in the first weld at 200A using 6011, then top with a more normal 125A or so using 7018. I heard a similar suggestion from another welder for technique, but the rod type was reversed - so one of them was confused. I have 6011 and 7018 rods ready to go, however, I don't know which to use when.

Any suggestions and/or recommendations are welcome.

Thanks - JayC

 

[gauthier]

Well,depends what the cutting edge is made of,maybe[probably] some kind of hardened higher carbon steel? and if thats the case,neither of the rods you mentioned would be the ones to use,,and those amps you mentioned really don't make much sense.

Maybe somebody has done something like this and will help out more.

But welding on something like that might require a preheat and even a post heat or at least slow cooling,not to mention the proper rod,,other wise,the first time you use it,it might just break off,cracking would be the problem if not done right.

 

[gerard]

The thickness of what you're welding will dicate the size of the rod which will then dictate what amps to use. The 6011 is a high penetration rod so you would use that for your first pass. The 7018 is more of a filler rod and will leave a nice bead so you would use that as a final and covering pass. You could also probably use 6013 which is mainly for pipe welding. All you're really doing is holding the new edge to the old so this isn't exactly critical welding. You should make sure you have it clamped well, then do a pass on one end, then the other, then the middle and let it cool a bit inbetween passes to minimize warping and metal expansion. If you do a long continuous pass from one end, you will have expansion of the steel and place internal stress on the metal.

 

[gauthier]

So,your saying the cutting edges,are made of mild steel?

 

[Shield Arc]

I would guess an "AR" plate, maybe AR-400.

 

[robs660]

Did this on my kubota. Took a cutting edge from a fisher plow and welded it right to the bottom of the bucket. I did it with my Hobart handler 240 mig. Highest amp setting 35 wire feed speed. It is rock solid and has worked like a dream for a while.

 

[rjmack]

I heard a similar suggestion from another welder for technique, but the rod type was reversed - so one of them was confused. I have 6011 and 7018 rods ready to go, however, I don't know which to use when.

i welded this grader blade on about 22 years ago, it has stood up to quite a bit of abuse, both summer and winter.

i would use 7018 only, but if it could be avoided, wouldn't try welding it to the existing cutting edge.

if possible, i would cut the old a/r q/t or whatever it is off, so that you can weld the replacement blade to the mild steel of the plow. the rational being that it's easier to weld hard to soft than some sort of hard to some other sort of hard, especially when your not sure exactly what they are.

i think hitting it with 6010 or 6011 is probably not a good idea.

whether you weld old to new, or new to mild blade, you definitely would need to preheat and post heat to stress relieve and try to arrange for some insulation to keep it hot for as many hours as possible. it never hurts to have a tiger torch handy and lots of propane. that foil back insulation works good.

i once welded a broken (3 pieces) rear axle on an f250 with a full floating rear end using this technique and 7018 only... it lasted for over a year, the guy was chewing his way up a gravel hill when it finally let go. i was surprised it didn't snap off on his way out the driveway

i have also tried repairing cutting edges on some large loaders that just would not cooperate... they formed cracks radiating random directions from the weld. the further i tried to chase the cracks, the further they radiated until the blade was more broken than not... so there is such a thing as a blade that just cannot be welded. it's almost like it already had microfractures and the heat just sent them heading every direction.

 

[jonyyuma]

That 200amp amperage was really too high, unless you have a huge ball-bat rod.There was correct ranges on the package the rods came in, also correct polarity.. Very high amperage won't do the trick, or make up for bad technique. I am talking about stick welding.

 

[gauthier]

Just depends on what the stuff is made of,I wouldn't know,but if its somekind of higher carbon and/or hardened steel,it would be like trying to weld cast iron,,,meaning,if it ain't done right,it won't work.

You might take a punch and hit mild steel with it,real hard and than hit the cutting edge and compare hole sizes or a drill bit.

 

[Dargo]

I have no idea what material your cutting edge is, but I've welded up dozens and dozens of scalloped excavator and backhoe buckets with 11018 rods or 110S wire if I could get any locally. I had a little 5 pound spool of 110 and used AR/O2 mix to weld up the scalloping in my excavator bucket about 3 or 4 years ago and I don't have any new scalloping between the teeth.

I had some of my early jobs crack that I didn't preheat, so I've since always preheated the parent material to at least 700 degrees and then used an O/A torch on the weld a bit to let it slowly cool. The last few, including my excavator bucket, I just buried the weld in sand as soon as I finished and it seemed to cool off slowly enough that way.

Honestly, you may be surprised at what will work though. A buddy put a nice divot in the cutting edge of his FEL bucket and asked me to come over and weld it up for him. I assumed he had what I would need. He only had a little, but nice, Hobart Handler buzz box and a box of 6013 rods he picked up at Lowes. Oh well...I ground it out and beveled it a bit and made several stringers to weld it up and then used his grinder to blend it in with the rest of his cutting edge. While it was still warm, he sprayed his cutting edge with a can of Kubota spray paint he had and it dried almost immediately. He's used his FEL constantly for the last year since I did that 'quickie' for him and he said he still can't see where it was fixed.

I dunno, maybe the cutting edges on some FEL buckets aren't all that hardened. I expected him to wear that weld off pretty quick clearing snow off his asphalt driveway and digging in some pretty rocky soil, but so far so good. I wouldn't have bet on it holding.

 

[Egon]

if possible, i would cut the old a/r q/t or whatever it is off, so that you can weld the replacement blade to the mild steel of the plow.

That is what was done on the two new cutting edges I had welded on to the buckets.

 

[Gary Fowler]

By not know what you are welding it is impossible to know what rod to use. You might query some of the FEL bucket folks that post on here for the correct welding rod. I agree with Egon that the best way would be to get a new blade and remove the worn out one and weld on a new one. It could be that the blades are just tempered and hardened on the edges and have a mild steel back edge and end so that they can be welded on with mild steel rod of your choice. I like the 7018 mild steel rod as it is more ductile than the 60xx series rods. IT stretches more before breaking than the 6010, 6011 0r 6013. I never liked the 7014 or 7013 rods as they also seem to be more subject to brittle fracture.
You may get away with welding the old blade to your old blade by preheating to 500F or so, I dont think heating any hotter will help a lot with preventing cracking. Stitch welding to avoid concentrating the weld cooling stresses may help also. But your easiest weld is going to be to weld the high carbon steel cutting blade (that is what I think it is) to the mild steel part of the bucket.

 

[Egon]

I agree with Egon

Others before Egon mentioned this.

Cutting edge should be the same material all the way through as they do wear down to a replacement point..

 

[SPYDERLK]

I have a piece of town plow cutting edge that I plan to weld onto my bucket to make a new cutting edge. I am going to weld it directly to what little is left of the original welded cutting edge, placing the new material under the old then welding around the edges. The suggestion I have so far is to gap the new edge slightly below the old edge (like 1/16") to prevent cracking. Then burn in the first weld at 200A using 6011, then top with a more normal 125A or so using 7018. I heard a similar suggestion from another welder for technique, but the rod type was reversed - so one of them was confused. I have 6011 and 7018 rods ready to go, however, I don't know which to use when.

Any suggestions and/or recommendations are welcome.

Thanks - JayC

I broke the cutting edge of my bucket 2 yrs ago pushing down a 18" tree. It broke at a point where a tooth bar had left a dimple in the edge and a very short crack had developed there that I didnt see. I fixed this 1/2 X 6" edge using 6011, 7018, and 11018. I started out using just the 11018 but found I was getting voids in the root pass. I went to 5/32 6011 for the root pass and then to the 7018 and then to the extreme strength 11018. It has been durable. You need about 50 more amps to burn the high strength rods and I couldnt help gouging the root when I used them.
larry

 

[rjmack]

rereading from the beginning, there is one other possibility. maybe the original 'cutting' edge is just mild steel?

easy enough to find out, (you should be able to find a spark trail chart online) and if it is you might want to (after shining everything up) clamp the new blade tight to the old one and hit it with the tiger torch. you should keep both pieces/blades hot enough that your spit doesn't just boil, it should dance across the surface. you will probably have to reheat a number of times to keep everything this hot during the process.

having laid out your stitching pattern ahead of time, start in the middle and put a good tack 1/2" or better, inward from each end of each stitch (front and back) and work your way simultaneously to the ends. reheat, then first pass 7018 1/8 @ 125 amps 2nd pass (if necessary) 7018 5/32 @ 165 amps give or take. after you are done welding, keep it hot for a while, then wrap it with insulation. i think about 6" of insulation in a warm shop should be enough that it is still warm the next morning... that should do it.

i used staggered stitches on mine 3/3 or 4/4 (too cold to go look right now)

--------xxxxxxxx--------xxxxxxxx--------xxxxxxxx--------xxxxxxxx
xxxxxxxx--------xxxxxxxx--------xxxxxxxx--------xxxxxxxx--------

i don't know that you have to go to all these lengths to make it work, but if you do... it should.:thumbsup:

 

[Shield Arc]

This might help to determine what type of steel it is.

 

[Inkomodius]

Ive done a lot of cutting edge install and replacement on bucket's graders ETC. I know our steel classification in Canada is different then the states. But here an AR steel is an atmospheric steel usually used on bridges where it doesn't need to be top coated, It has higher amounts of nickel in it to prevent corrosion.

For cutting edges that we have to get custom made, we get them generally made of a QT steel, which is not a mild steel, Its carbon content is higher and is quenched and tempered. They have grades from QT-100 - QT- 400. (there may be more but is what I am familiar with)

QT 100 is what I think you Americans refer to as T1 steel.

As far as welding it, I use 7018 or a t9 flux core variant that has the same finished properties as 7018 (hardness, notch rating)

The thing with this stuff is preheat. Not just the material you are welding, but the surrounding area, post heat treatment is just as important as preheat. If it cools to fast it can lead to cracking and weld failure.

On this bucket that I replaced the tooth mount on, I preheated about 2 square feet to about 120 degrees (Got all visible moisture out of the steel) and after welding I covered the tooth with a welding blanket and after 2 hours it was still hot to the touch.

So preheat an IMO I wouldn't use a 60XX rod. Stay with 7018 and you should be fine

 

[Inkomodius]

Also I read it again about gapping it? Dont. Gapping it will create cracks, you want a tight fit. Having them pressed together will distribute forces evenly as compared to the weld taking all the forces.

 

[gauthier]

I don't know about that for sure,,,,,weld something,,weld contracts as it cools,,if it ain't got no where to contract,,,but,yeah it would be safer to weld hardened steel to mild steel as opposed to hardened to hardened,[dilution],,would try and get some 8018-9018,,or 7010,8010,,,would preheat it up to 300 or 400 degrees,,[whole thing,would need an act torch],,,maybe have some dirt to throw on it,so it cools slower.

 

[rjmack]

I don't know about that for sure,,,,,weld something,,weld contracts as it cools,,if it ain't got no where to contract

you aren't thinking that through. the preheat expands both pieces of steel, the stress relieving lets the connecting points 'mellow' out.

if you watch those kung fu guys breaking ice/bricks whatever, they keep a space between all the pieces... there is a reason for that... maybe not exactly the reason that a space between the steel pieces is not good, but a good story nonetheless.:laughing:

really, the stress relieving will allow everything to stretch until it is comfortable. you are going to get a certain amount of electrolysis between the pieces anyway, why make it worse with a gap? crud will get in there, get wet, then freeze... just not a good plan.

btw, forget the 7010, 8010, or any 10... the fast freeze rod works directly contrary to the slowcool process that is required dealing with hard steels. thermal shock is the achilles heel of most hard steels, and the susceptibility to thermal shock goes both ways... why use a rod that cools quickly, and is known to be brittle in it's own right, in a situation like this?