Welding Cast Iron

I'm already not much of a welder.  Then on Saturday, I was driving with my head up my butt thinking of a million other things and caught a row marker on a fence post pulling into the next field.  There's 2 "small" pieces that weld to the bushing that the pin goes through where the joint in the middle of the marker folds.  All this is cast.  Not very thick, 1/4 inch.

I did it 'old school'.....BRAZED the busted tabs onto the trannny of my Willys PU. PRE heat is essential as clay said.

I used cast iron rod.  I can't be specific because I didn't look, as Dad handed me a few sticks out of the pack he bought for cast iron, said it's "cast rod".

Edited by Tbone95 - 20 May 2019 at 12:30pm

steve(ill) wrote: If its a little corner of the casting with not much MEAT left to it, I would replace... I cut a 1/4 inch plate ( steel) a little oversize and get more area to weld if possible... VEE it out and weld to the original casting........... then redrill the hole later to the correct size.. Temp is just warm, not red.... 200- 250 degrees is OK... and when your done let it cool SLOW. Keep out of any wind or cool areas.. Cover with a canvas tarp or blanket can help.

Here is a little drawing for further explaination.. If the little cast eye is too small to weld QUALITY... then I grind it all off.  ( Broken at the GREEN line -- grind back to the RED line). Then I can cut a steel plate to approx. size and bevel both sides to a VEE.. Weld this up with some type of nickel rod... let it cool, the grind to shape and drill the hole.

Do as you wish, but there is a reason why industry uses very little cast iron welding, brazing is superior as there is no heat affected zone, thus no embrittlement, and the strength and ductility of the brass is almost identical to cast iron. Proper preparation is to clean the casting of grease and oil, and chip where the joint will be, any form of abrasion, or even wire wheel use will cause smearing of the graphite inherent to cast iron which impedes proper welding or brazing. Pre heat and post heat and controlled cooling rates are important. Any form of welding will impart a brittle heat affected zone that reduces strength of the joint. One exception to this is spray welding with a Bronze-Nickel powder which actually alloys with the cast iron to reduce this heat affected zone to some degree, and can be used on burned out cast iron as in manifolds where conventional brazing can not be applied.

while you are playing with welding, get on the phone and order the new part!

cabinhollow wrote: This reminds me of a 20 year navy guy I know. He was chief elc  on a ship. They had a oven you could drive a forklift into for cleaning motors. The welding shop chief ask him about using the oven. They had a very large cast iron part to weld. They brought it up to temp and then had 3-4 welders take turns going into the oven to do the welding.  It was 90 sec. per welder, with medic on hand and etc. 4-5 hour job, not counting per heat and cool down.

On small parts brazing is the best way to make it hold.

Years ago we had a welding shop in Columbia, Mo. If you remember the old M's and Super M,s had a tendency to lose the outboard bearing on the drive axle. When this happened it cracked the axle housing. My brother in law would take it apart and take it in and they would braze it up. Never broke again.   Leon

Well my rig job lasted through 15 acres of soybeans last night. Almost done for the season. If it lasts the rest of the way, I’d like to be done spending time and money on it. Maybe next spring, if there’s enough pennies in the jar, get me some new Yetters. Part obsolete as is. Lots of decisions to make, as my fert wagon is pretty well f’ed as well. Maybe a different rig all together set up for liquid?