Cast iron repair

By andyz Date 02-12-2005 22:21

I have a differential case fron a small tractor that has a hole in the bottom. Someone patched it with a piece of steel and JB Weld. I do not have the piece that is missing. I would like to repair it a bit more professionally. Can I patch it with steel and braze or weld it? Will the steel expand/contract at a different rate than the cast iron and cause problems? Should I overlap the piece or can I cut and fit a piece to make a flush repair? Or should I just drill and bolt a piece with a gasket?I have an AC stick welder and a mig. Is there a rod or wire that will do the job for me or should I look for someone to do it for me? Any thoughts? Thanks

By billvanderhoof (****)

Date 02-13-2005 05:30

Steel and cast iron do expand at different rates but the fact that a patch glued on with JBweld worked indicates that the patch is small enough that the problem will not arise. You can either braze or weld it. If you braze it I would overlap it and let the braze sweat under the patch. If you weld it you can fit the patch into the hole if you want to. If you weld it use one of the high nickel fillers which will bill itself as "for machinable cast iron repairs". Either machine will work, you may find it easier to get small amounts of filler for the stick machine. (I would prefer stick anyway but that's just me). Weld an inch or so then peen the weld with the pointy end of a not too sharp chipping hammer as it cools, repeat till done. Clean off all the JBweld and rear end grease first.
Bill