Well, I made the repair to the tractor today that so many of you were gracious enough to advise me about. I was under the assumption, (and still am), that it is cast steel. I ground out the crack to about 1/4" in depth as the material is 1/2" thick. I pre-heated to about 200F, welded verticle up as well as in the overhead position with 7018, then post-heated. Because I'm not exactly proficient with 7018 in these positions, I had to make several passes, grinding and checking/maintaining pre-heat temps between passes. When I was done, I noticed that some of the overhead welds had begun to crack, not in the position the original crack was in, but instead the cracks were all over the ground, (grinded?),weld beads and looked like tiny little lightning bolts! The weld that was in the verticle position survived okay however, until I took the tractor out for a 'test drive'. After putting some strain on the front end, I've now noticed that it too is beginning to cracl. Just a tiny little hair-line crack, right where the original crack had formed.
So, I guess my question NOW is, What's next?
Anyone wanna buy a slightly cracked, 40 year old tractor? LOL!
chaikwa.
Just a thought
Not knowing what material you have is a real problem. Other replies you received gave you some really good ideas. Guess at this point I would get some nickel rod and see how it works. Follow same procedures as before. There is a rod made by Harris Welco called "supermissle" which is puposed to be able to join anything. Sales info on it says if you're not sure what material you have then try this rod first. I have used these rods a few times just for the hell of it to see how well they work and thought they were pretty good. Drawback is that they are really expensive. The ones I used were free bees otherwise I probally would not have bought them due to cost. Think they are slightly lower than Ni rods on a cost basis.
http://www.jwharris.com/welref/techguide/steel_cover/
Good luck
kam
Hi Kam
I believe this "supermissile" is just an E312 electrode. ENi-CI will be better for cast iron.
Regards
Niekie Jooste
Fabristruct Solutions
Hello Niekie
That could very well be right. No chemistry is given on the site.
Regards
kam
Was the crack all the way through the part, or when you said you ground 1/4" deep, did that completely remove the crack? The crack should be completely removed, or if it is all the way through, grind half way though, weld, then grind the back side through to sound weld metal and then weld the back side. If there was any crack remaining, it would create problems for any weld metal.
The crack was all the way thru, and it is 1/2" thick material. Welding from the backside isn't an option, as I can't GET to the backside! In order to get at the backside, I would have to disassemble the entire tractor as this is the frame. If I'm going to do that, I might as well replace the whole frame if I could find one.
Thanks for the reply!
chaikwa.
Its been a while for me but I believe you can get the radiator and most of the stuff foreward of it off the frame (including the front wheels and steering if necessary). A helper would be nice- neither JD or Cat ever worried about making heavy parts. When you get it where you can see it then you can fix it. Mblaha's post in the old thread describes a perfect repair. I'm sure this isn't what you want to hear if you're trying to get that hay into the barn or some such but sometimes you just have to bite the bullet. I'm guessing but you and a helper can probably finish this in about a day.
May all your bolts unscrew instead of breaking-
Bill
My guess is the repair weld cracked because of the sharp notch the rest of the existing crack created on the back of the weld. Not to mention that the material was then essentially only half as thick as was intended for the original design. You might try again with grinding out the weld completely. You can weld it all from one side with several techniques. (Open root, with integral steel backing, or with a non-fused backing such as copper or ceramic.) The easiest way if your technique is good enough, would probably be to grind out the crack until there is about 1/16" of metal left, then burn through the last bit with the weld, creating a full penetration joint. The technique would probably be easiest with integral steel backing, but it takes more work to set up that way, and access to the back might be difficult. Whatever way you decide to try, good luck!!
Not having alot of time to get on the puter this weekend, (Helping son put a steel roof on his house in 90 and 100 degree weather lol) I was going to suggest that this is where the problem came from as well. I would try this same approach. I agree that the cracks propegated from leaving too much land. When I made the repair, I took it down to less than 1/8" land. I would also suggest that you use a rotary file rather than a grinding disc. I forgot to mention this in the previous post. If you are not concerned about keeping the 60 orginal, may I suggest that after you finish welding, you find a pice of 1/2" A36 long enough and wide enough to cover this part of the frame. Drill holes that match the frame, and bolt onto the frame with as large of bolts, if memory serves, 5/8" as the holes in the frame will allow. A coat of primer and seveal coats of John Deere Green will make the tractor look good as new. If somone questions this, tell them is it is for an attachement LOL
Good luck
Mike
Hi Chaikwa,
It's hard to suggest the correct repair procedure from here, without seeing the part. My experiences with repairing cast are that taking shortcuts with a welding procedure doesn't work too well. The best way to weld repair, in my opinion, is to remove the entire crack, preheat the entire part, or as much of it as possible, weld with a cast electrode, preheat in between passes, preheat again after welding, and then let the part cool slowly by burying in warm, dry sand for about 24 hours.
It sounds like this is not a very good option for you, considering the size of the part and the amount of work involved.
Another option that you may be able to consider is a mechanical repair such as the use of high strength bolts to hold the part together.
Can you drill few holes all the way through the part, perpendicular to the crack and slide in some bolts? Or, maybe you can drill through the material on one side of the crack and tap threads into the opposite side?
Just a thought...
Tim
Hi Tim,
Thanks for your reply. Thank you to EVERYBODY, actually.
I don't know exactly WHAT my next course of action with this thing is going to be, but you're right Tim, there are no short-cuts that are successful in ANY type of welding, let alone cast.
I have to go back to Massachusetts for a couple of weeks, starting Monday, as I still have a small shop there that needs looking in on from time to time. Maybe some revelation will come to me while I'm there and I can come back and fix this thing up right! I was actually thinking of building an external sub-frame assembly that I could bolt into place on the existing frame that's cracked, but then the frame would probably only crack MORE wherever I drilled for the bolt holes.
We'll see. Between all the good suggestions I've received here, I'm sure I can come up with something!
chaikwa.
Cast is forgiving when it comes to drilling bolt holes, however, I do recommend counter sinking the edge of the hole in order to eliminate the sharp edge stress riser.
Good Luck!
Tim
I am still under the impression that a 60 John Deere's frame is cast steel which should be welded with Dry, kept in an oven at 250 degrees F after the seal has been broken. May I suggest contacting John Deere themselves to see exactly what the composition of the frame is? When calling, make sure to have the serial # handy.
Mike
Forgot to add E7018 to the part about dry kept in an oven.
Mike
Thanks Mike.
I did in fact use 7018, and from a new unsealed container.
I think you're right about it being cast STEEL. I didn't see any of the characteristics I'm used to seeing when looking at broken cast iron, such as that 'porous' look, (those fine 'holes' all through it, for lack of better words).
Here's a question: Can I weld mild steel to cast steel without compromising the cast? It's extremely hard to get behind this frame plate to install bolts or nuts, and I'm thinking of making an exterior frame to reinforce the cast piece. Instead of bolting it into place, I was wondering about stitch welding with the proper pre and post heat processes.
Thanks again.
chaikwa.
I will leave that one for the Metalurgy guru's :)
A question I failed to ask is, just exactly where is the crack. The one I did was about 1'6" from the sheetmetal over the radiator. There are bolt holes in front and in back of the crack.
I knew you had welded it with E7018, I just forgot to add it in my post.
Maybe you could make the frame you are talking about wrap the frame. By this I mean using 3 pieces of steel, .5" or thicker, and bolting it to the 2 bolt holes in the front where we used to mount the 2 row cutlivator so we could enjoy the sun in 1st gear day after day after day. Oppps sorry got off on memory lane here lol, anyway, mount this to the front, and one plate on each side. I do know you can get your hands in there with lots of paitience and bolt through the existing frame. Weld the 2 side pieces to the front piece and make a U. Does this make sence or am I babbling incoherently?
Mike
Hi Mike,
Yeah, you're making perfect sense actually. The only problem, (I think), is that the crack runs from one of those front bolt holes you're talking about, DOWN the front, then UNDERNEATH along the left side, right beside the axle pedestal, makes a 90 degree inward turn and ends at the large hole right smack-dab in the center of the casting, (under & behind the radiator). Another crack starts at opposite side of that large hole and begins to take a path similar to the other one but it hasn't progressed as far yet. I ground out that smaller crack and welded it as well, and it doesn't seem to have re-cracked... YET!
What you're talking about in terms of wrapping the frame with a reinforcement is exactly what I had in mind too, except I thought maybe I could weld it in place as opposed to bolting it.
Any thoughts about this? Thanks!
chaikwa.
I understand. Hmmmm. I guess it is worth a try. I guess before you weld it though, I still suggest you contact John Deere and find out what the material composition is. Your crack is alot further to the front or the tractor than mine was. I am hoping one of the metalurgist will hop in here and give us an answer about welding the steel to the frame. I think it is worth trying, but I still think you need to bolt it in as many places as you possibly can along with the welding. Make sure if you weld it, that you do not leave any craters at the end of the welds. When you come to the end of a weld, reverse your direction and go back into the weld for at least .25 and maybe even .5. Another way would be to weld half the weld in one direction and weld the other half in the other direction. Again, make sure you preheat and if you can, before welding, steam clean or pressure wash to remove as much of the oil, grease and sludge that is generaly built up. Clean the paint off with a rotary file down to nice shiny metal in any area you are going to weld. You may want to consider adding a 4th piece of steel. This one I would put under the wrap, under the crack covering both sides. Say a 8 inch wide piece. Make this pice 1" longer than the piece you are going to put on the front. I would also suggest putting at least a 30 degree or even 45 degree bevel on each side of this one so you can get some good penetration in to the pieces that run paralell with the frame. This will help carry the load should the welds crack any more. Anyone else out there have any more suggestions?
Mike
No ideas, and without a real body of experience on this particular kind of work I am curious about why bronze wasn't considered. I presume it would still be the choice for a crack in the engine block? This isn't a "horse-out-of-the-barn" comment; if I knew what worked I would have contributed... I defer to those who work on this equipment for clarification. I am fortunate to hve largely been able to avoid work on cast... and when it's unavoidable I rely heavily on the power of prayer.
d
Hi Chaikwa
Regarding the issue of welding wrought steel to cast steel, you should have little problems. This sort of thing is done every day. Theoretically cast steel shouls weld almost the same as the equivalent wrought product.
There are however some potential problems when welding cast steel, such as the steel being rather "dirty". When some castings are not going to be welded, the foundary often takes the oportunity of getting rid of some less than optimum quality steel that may be lurking around. If the casting is dirty, it may have high levels of phosphorus or sulphur or lead etc. present. This will result in poor weldability of the steel.
Another potential problem is that the casting is a "free machining" grade of steel. In other words, it is purposely high in sulphur or lead. If the frame had other welds to it during fabrication, then it almost certainly would not be a free machining grade. If however it had no welding, but quite a lot of machining, it may be a free machining grade.
Hope this helps.
Regards
Niekie Jooste
Fabristruct Solutions
Forum
