Cast iron repair?

[jwmorris]

You had that in post #2, if you don't have to drill and tap.

 

[the old grind]

Arc weld, we're throwing a lot at you, and good stuff too, but might be more help sorting the options with some pics. Can we help you with that??

I still say how well you can access the repair area to prep/weld/braze/whatever may bear somewhat on what will best git 'er done. btw: On some page you might have to refresh us on what gear/tools you can take to the job way out there ... ....

 

[Arc weld]

I don't have a TIG torch. yomax4 suggested a 312 stainless type rod if I don't know what it is. It is cast iron. I've also read that a 55-60% nickel rod would work in addition to silicon bronze. I hope I can just clean up the threads after welding. I'll leave a bolt in while welding. I've read other info that just says nickel rods but doesn't mention if they are 55% or 99%. That's why I'm asking. I have seen cast iron welded with stainless, nickel and other types of rods. If I'm just doing quick tacks I need a rod that will get good fusion right away. What little cast I've done seems to go on cold and not completely fuse at the start.

 

[Arc weld]

I have an SA 200, a die grinder and a torch set. There is a raised boss about 3/4" in diameter that is threaded for the oil cooler. The threaded part of this boss pulled off, It's about 3/8" thick. I was planning to bevel the broken piece and grind a little on the other side to clean it up for the weld. The injection pump is about 6 to 8" above this and there is another bracket with gaskets and such on the back of the engine about 8" away. Where the repair is is relatively easy to get at. I think if I put most of the bevel on the broken piece, I should be able to see what I'm doing pretty well.

 

[CliffordK]

If you don't want the bolt welded into the place, (or if it is a problem for it to become permanently part of the engine), I'd probably remove it.

I suppose you could put in a stud instead of a bolt, which might not be a bad idea. Then if it is welded in place, it is ok. If it comes out, it isn't bad either.

You can purchase "bottoming taps" for tapping into blind holes.

 

[jwmorris]

If you think you might weld a bolt in place use a brass or aluminum bolt. Brass bolts you might find at a local boat supply house but both are easy to find on the internet.

Is there anything else close to the broken boss? Maybe you just fabricate a bracket that hooks to other mounting bolts and has a provision to attach your oil cooler.? At least then you would be working with a familiar metal.

 

[Mark @ Everlast]

I'd suggest brazing it. It's a sure fire method, and relatively strong if done properly. You have a 931? I've had the injection pump off of one. Just keep the pump and engine in the same place you took it off, (and mark the teeth position together if possible) it won't be a big issue.

 

[EdGranelli]

Without a picture it is hard to give advice. Can you use a mirror and take a picture that way? Anyhow, here is an interesting alternative to a permanent repair if there is room. Speaking of room can you bend up a piece of tin to keep the heat away from the pump and its lines? I went to Spring Carlisle and watched the demonstration of a torch. The gentleman had an old exhaust manifold that had slits cut in it. He used an old dirty piston ring, they are cast iron and I did not know that, preheated the small manifold, heated the piston ring and dipped it in the flux and proceeded to weld the slit! He made it look easy. After he welded it he ran the torch over the piece to take the stress out of the welded area. The best part is it is soft and can be drilled and tapped if needed. This is the location of a video demonstration of the torch. I do not know how to add the link but it is easy enough to type it in. torchweld.com - youtube To watch the cast iron welding only, move the button to about 3:30 seconds into the video.

 

[Arc weld]

I have gas welded cast iron in school as well as brazed it. Where I work we sell cooling gel that can be sprayed on to keep parts cool but for any O/A process, you need LOTS of heat(800deg's. +). I have read several techniques on the cold repair method yomax4 suggested and this looks like the easiest repair for me. I just want to figure out the best rod to use.