I have a cast iron housing on a front end loader cylinder that is cracked. It's an obsolete cylinder, so I can't just buy a new one. I need to have it welded, but so far haven't had any luck finding anyone that can do it.
So what kind of shop should I be looking for?
A Welding Shop.
Welding cast iron is tricky. It has to be pre-heated, welded, post heated and cooled slowly. You need to use special nickle rods on it.
earlier threads that are related:
http://grassrootsmotorsports.com/forum/grm/can-you-weld-cast-iron/43155/page1/
http://grassrootsmotorsports.com/forum/grm/can-i-weld-cast-iron-with-a-mig/48251/page1/
I'd call a reputable machine shop and ask them if they know anyone who's skilled with welding cast.....it is difficult to do right. (Check those two links for more info.)
This always looked like a neat solution for repairing cast iron parts.
look for mine or shipping companies or contact a CAT/DEERE Dealer that does equipment maintenance. I am certain in your area there is someone who specializes in this kind of welding. The amount of welding that goes on to rebuild worn heavy equipment repair/rebuilding is amazing.
What method is used? TIG, heliarc?
TIG
I used my miller mig with std wire on my tractor on a git r dun repair, busted steering arm. I used a chunk of angle iron over the break, preheated the whole thing with a propane torch, welded the e367M3 out of it on the highest heat setting, used the torch to try and cool it off slowishlike, and hoped it would hold for the rest of the job that day. That was 3 years ago...haven't bothered replacing that part yet.
I think the trouble with cast iron is there are a few different types. "Cast iron" is a generic term, to weld on it you need to know what type of metal it is. I believe you need to use a nickel based welding rod on it. I can ask my old man to look at the metals welding book. I hear cast iron is tough to weld on as the material will crystallize and become brittle with the extreme heat of welding.
I had my manifold welded up last summer, cast iron. Lots of pre-heat, nickel rod, and it's held awesomely since.
The method used is whatever your crusty old weldor (welder=a machine. weldor=person who welds) wants to use. There's people who achieve brilliance with an ancient Lincoln "tombstone" stick machine, every day.
I believe one of the primary concerns is that if not done properly it will warp like mad. Had an exhaust manifold welded up once, wrong, warped the crap out of it. Took a LOT of grinding / belt sanding to get it flat again.
aircooled wrote: I believe one of the primary concerns is that if not done properly it will warp like mad. Had an exhaust manifold welded up once, wrong, warped the crap out of it. Took a LOT of grinding / belt sanding to get it flat again.
That's where pre-heat and post cooling come it. A common old school method is to heat it on a charcoal fire, do the weld, return it to the fire and leave it 'til it burns out overnight and is cool in the morning.
Depending on where the break is brazing might be a better option, less heat, so less chance of complication.
It's at a shop now. I'm waiting to see if it's repairable or not.
I've welded many exhaust manifolds and tubes to rearends. This is my recipe.
Drill holes in end of crack.
Grind open crack.
Fill full of charcoal briquettes, add lighter fluid, and cook.
When hot TIG with nickel rod.
Add a few more briquettes, and cover in sand.
Let simmer till cool.
Cast iron welding is a lot easier than people tend to think, or make it. The crucial needs of pre and post heating have long gone with the nickle rods. If you've got an arc welder, you can do it yourself. The rods you need for a buzz box to do the repairs are available at Tractor Supply. You can buy them at a welding house as well.
Ferroweld is the easiest, but it's not particularly machinable. I use this rod on oil soaked castings and the like. It's worked very well for me. If you don't need to machine down the surfaces after welding, this is the rod I'd recommend.
Softweld, either 99 or 55 if you do need to machine the surfaces after welding. A little more persnickety to weld with, but not hard.
In reply to foxtrapper:
Now you tell me (slaps own forehead)...
I used to weld a lot of cast iron pillow block bearing housings. I never had any luck with anything but MG200 sticks
Everytime I tried to use the TIG the cast iron acted like I wasn't using any shielding gas at all. As soon as it puddled it bubbled up and went frothy. This was freshly machined new parts so contamination shouldn't have been an issue. I had the same basic issue with MIG.
In reply to welderman:
Pretty on point canoe there.
Canoe deleted, thanks T.J.!
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