Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / General Welding Discussion / cast materials
- - By chaikwa (*) Date 08-10-2003 00:15
I don't post that often but I read the board everyday. I've learned more here than I've learned anywhere else in the last 15 years.

Anyway, my question is: I have a 1950's vintage model 60 John Deere tricycle type tractor. The housing that supports the front wheel assembly, which is also the front of the mainframe, has cracked. I suppose it's just fatigued from years of 90 degree angle turns under load. The material looks to be cast and I'm going to try mig welding it, (I think). The only 2 choices I have are mig or stick. What I was wondering is if a preheat is needed, (as a rule), on cast before welding. I've had limited success in the past with cast, sometimes it works, sometimes it doesn't. But I have nothing to lose here so I gotta try!

Any help that anyone can give me will be greatly appreciated.
Parent - - By mark8702 (*) Date 08-10-2003 00:18
HEY HEY HEY....I got one just like that I tried Migging it but it cracked I do believe that is cast but i am not sure....I wish somebody could explain to me but i already cut the pedals off with a torch....hehe....
Parent - By brande (***) Date 08-10-2003 04:11
One crack is not always the end of a project.

Often, by grinding out the crack and rewelding, a satisfactory joint can be obtained. An oil soaked or contaminated casting can cause cracking at times.

A slight preheat can help in this regard as well. This will slow the cooling rate of the part and minimize cracking. I would go at least 200 deg F and as high as 600 deg F on highly restrained cast iron


If you can't get a good weld in three weld/grindouts, I might start thinking of other things.

Let us know how you make out...

Good Luck

brande
Parent - - By brande (***) Date 08-10-2003 04:04
Don't make the mistake of confusing cast steel with cast iron.

Cast steel is easily handled with 7018 or similar filler. Cast iron requires a different filler, due to it's high carbon content. A spark test should differentiate the two.

Run a grinder on the material and let us know what you see.
Spark shape, color, and quantity are important. If you think it may be cast steel, grind some steel and grind the casting. If it is cast steel, the sparks will be close.

Keep us posted..

Good Luck

brande
Parent - By chaikwa (*) Date 08-10-2003 12:09
Thank you brande, I had forgotten about that. I will do exactly that and let you know before I weld it. It will probably be a few days before I can get to it tho, as we have a funeral to attend and all the 'stuff' that goes with it over the next 2 days.

chaikwa
Parent - - By chaikwa (*) Date 08-13-2003 12:50
This morning I FINALLY had a chance to run a grinder in that crack on the tractor. The sparks produced were a darker orange in color than mild steel, and they were more like little stars than the straight sparks found when grinding mild steel.

So this means what? That it's a cast iron material? What process would any of you recommend for welding? And what filler material?

Thank you and looking forward to your replies!

chaikwa
Parent - - By jwright650 (*****) Date 08-13-2003 13:06
chaikwa,

http://www.tpub.com/steelworker1/5.htm

Here is a link that was posted on the forum a while back by flashburner1.
It shows the different types of sparks you would expect for different types of materials. Also try the search function for "sparks". There were several discussions about this subject.
Check out the link and let me know what you think about your material.
After you have an idea about which material you have then someone could offer a filler and a process of welding for you.
Happy Grinding :)
John Wright
Parent - By chaikwa (*) Date 08-13-2003 22:36
Thanks John! I went to that site and from the information there, I'm relatively sure the material in question is cast iron. I have alot of the little 'spark-lies' when I grind it, not the straight stream of sparks I usually get with mild steel. Also, the volume produced compared to mild steel was much less as well.

chaikwa
Parent - - By billvanderhoof (****) Date 08-10-2003 04:46
Great tractor- spent considerable time on one of those. We broke the upright part from the frame to the front wheel once. If welding doesn't work try-
http://www.valu-bilt.com
They seem to be the successor to Central Tractor who used to have a great breakers yard for tractor parts.
Bill
Parent - By chaikwa (*) Date 08-10-2003 12:11
Thanks! I'll check out that site. I live in southwest Michigan and we have a pretty well stocked vintage tractor junk yard near here too. (Stamm's, for any of you that may be familiar) I hope that I can successfully make the repair however, as I really, really, REALLY don't want to pull that pig apart!

chaikwa
Parent - - By bulldog5585 Date 08-15-2003 21:34
I would DEFINATELY not MIG weld that cast. I'm not familiar with tractors but this sounds like a steering knuckle which i've worked on extensively. I've always had success preheating to 250 F and welding with 7018 electrode. Make sure your not going to damage any bushings or anything by heating the part up so much! Also yeah, grind the crack as best u can and really try to pour a big weld on it, I generally do three passes. One thing nobody has mentioned is stop drilling the end of the crack, if u drill into the materal at the very tip of the crack before welding, it will reduce the risk of the crack continuing through the material. Try to let it cool as slow as possible too, meaning no open windows or doors and no fans around. Hope this helps.
Parent - - By chaikwa (*) Date 08-16-2003 01:58
Hey Bulldog, thanks for the reply! I was kind of leaning towards the 7018 too. That was the only suggestion I got here after determining that is IS in fact cast iron, and now you have made my mind up for me I think!

I can do a stop drill at one end of the crack but not the other. This is the whole front piece of the tractor and there is one area I won't be able to get into. Why it didn't crack all the way from one side to the other is a mystery to me! And it's been cracked for quite some time I'd guess, because the crack is all rusty, (that's how I found the problem).

Thanks again for your help!

chaikwa
Parent - - By flashburner1 (*) Date 08-16-2003 03:06
I have welded cast iron many times - Tempil-sticks will give you the correct pre heat / post heat temperature / and it comes with a chart. Your local supplier should have them in stock or can order. If you want to mig weld it there are some companies that make wire expressly for cast iron (expensive). Look at Inco-Alloys web site -http://www.specialmetalswelding.com/products/ni-rod/nirod.htm - it is the brand I use.
Brian
Parent - By chaikwa (*) Date 08-17-2003 01:52
Thank you Brian, and all of you that hve responded. I'm going to attempt this next week and I'll let you all know how I make out.

chaikwa.
Parent - - By billvanderhoof (****) Date 08-17-2003 06:19
It might have cracked while it was cooling at the foundry. Consider using one of the nickel based cast iron rods. They produce a nice ductile deposit which isn't nearly as likely to crack as it cools. Groove out as much of the crack as you can, put in the weld a little at a time and peen it as it cools. All advice above about preheat and stop drilling etc. still applies.
Bill
Parent - - By chaikwa (*) Date 08-17-2003 13:12
Heh, no. It didn't crack at the foundry I don't think. It was ok about 6 months ago and I've been using the tractor pretty hard for the last 3 months or so, doing things with it that it just wasn't designed to do~! I think it's more a case of the poor thing being 45+ years old, and me using it like it was 3 years old!

Those rods designed for cast material: do they have welding characteristics similar to 'regular' rod? Should I ask for any particular type? It isn't like I have a piece of similar cast material around to try them out and get used to them. I'm just wondering what to expect so I don't screw it up any further. I've never used these rods before.

Thanks alot Bill.

chaikwa
Parent - - By billvanderhoof (****) Date 08-18-2003 05:51
I never thought they were particularly difficult to use. Flashburner1's link above is informative. Your friendly local welding supplies man will probably be the best source for info about what he sells. Don't forget to mention the position the weld is in.
Bill
Parent - - By MBlaha (***) Date 08-18-2003 12:48
Bill

I welded up the frame of a 720 JD Diesel on both sides. Having grown up on A's, B's, 50's, 60's, and a 720, the age difference between a 60 and 720 would be 6 years at the most. It should be made out of cast steel. I ground out the crack to leave a aproximately 1/8" land. and gave myself a strong 60 degree included bevel. I preheated the frame to 150 and welded it vertically up with Lincoln E7018, using a backstep welding method. To keep interpass temperature at a minimum, I welded on one side, then moved to the other side taking a fair amount of time inbetween passes. I did that back in 1986 and it is still being used almost every day.

Mike
Parent - By chaikwa (*) Date 08-18-2003 13:08
Maybe I'll try 7018 first then and see if it works. If it doesn't, I can grind it out and try the rod for cast iron. When I test ground this stuff, it definately didn't give me the spark characteristics of regular mild steel, so I'll see what happens.

The other problem is that it will be a verticle as well as an overhead weld, because the crack runs down from the top of the casting where the radiator mounts, to the underneath side where the front axle pedestal mounts, then almost to the opposite side where it starts back up again. AND, unless I pull the whole front of the tractor apart, I can only weld these exposed areas.

Thanks for your reply! I'll see what happens.

chaikwa
Parent - By billvanderhoof (****) Date 08-19-2003 03:54
No argument there, good job. The only thing was that there was some doubt about the material. I agree that it is most likely cast steel since cast iron would not perform very well in this application and these tractors don't have a reputation for falling in two. A lot of cast steels have alloying agents that can confuse spark tests. Still, in the face of unsureness, the nickel rods work on either cast iron or steel. The disadvantage is cost but the repair is relatively small so expensive rods won't be a killer. If it is cast steel 7018 is appropriate.
Bill
Parent - By chaikwa (*) Date 08-18-2003 13:08
Thanks again Bill!
Up Topic Welding Industry / General Welding Discussion / cast materials

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill