Welding Cast Iron Block

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Keith Morganstein
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Re: Welding Cast Iron Block

Post by Keith Morganstein » Thu Mar 08, 2018 9:18 pm

If you cut out the damage in way that a cast iron piece can key into it (and it looks like the damage will lend itself to that) fit the piece very closely, stitch it with locks and pins, it will be a good repair.
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Re: Welding Cast Iron Block

Post by fordified » Thu Mar 08, 2018 9:41 pm

I'm sold. I'm going to put it on the mill and square it up and either stitch or bolt it in or both. I'll put epoxy all over it for good measure.

Thanks for all the advice I really appreciate it.

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Re: Welding Cast Iron Block

Post by cgarb » Thu Mar 08, 2018 9:42 pm

Maybe mill out some more with a dovetail cutter and fit a piece of iron to dovetail in there tight, then pin the edges, no way that's moving around once that's done. Solid repair that should hold up well, little creative grinder work and some paint...good as new.

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Re: Welding Cast Iron Block

Post by KnightEngines » Thu Mar 08, 2018 10:07 pm

If you mill it out you'll have to grind a radius into the corners - or use an end mill with a radius. You don't want any 90 deg corners in there to get a crack started.
Stitching in a close fitting chunk of metal will be the best repair, use the Lock N Stitch plugs with the hook threads that pull the metal together, they're a bit of a PITA to work with but work very well.

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Re: Welding Cast Iron Block

Post by Sparksalot » Sat Mar 10, 2018 3:47 am

If you use LOCK-N-STITCH for the repair epoxy is a poor choice for sealant. The easiest and probably best choice is what LOCK-N-STITCH recommends and offers. You don't need or want gooey epoxy all over the place as you drill, tap and install the stitches into the second and third set of overlapping holes.

The company has videos showing the process.

A repair approach not mentioned is silver brazing. I've used products offered by Muggy Weld for many years with great success on what appeared to be hopeless cases of cast iron. Check them out.

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Re: Welding Cast Iron Block

Post by engineguyBill » Mon Mar 12, 2018 12:35 pm

A cracked cast iron block can be successfully repaired by a competent welder, but when a whole chunk is kicked out, the project becomes much more complicated. However, I have seen seriously wounded blocks that have been successfully repaired with JB Weld.
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Re: Welding Cast Iron Block

Post by BILL-C » Mon Mar 12, 2018 12:50 pm

I'm pretty sure that most of the people posting comments aren't familiar with this block and don't know that the passage down the pan rail is a gundrilled full oil pressure passage to feed the piston oil squirter that is supposed to bolt to the missing piece of oil pan rail.
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Re: Welding Cast Iron Block

Post by cgarb » Mon Mar 12, 2018 3:56 pm

I did see that passage, If he had access to redrill the hole with a long drill, a precisely machined press fit dovetail with a little sealant when assembled would in my opinion seal the passage. After its set, drill through the added piece...should work unless you hit water doing so.

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Re: Welding Cast Iron Block

Post by Dave Koehler » Mon Mar 12, 2018 4:26 pm

To avoid dealing with a rattling, bouncy drill bit what I do with channels might work here.
I machine up a piece of carbon the size of the channel and weld over it. When done break the carbon out of there.
In aluminum, stainless can work also but it's a bit pricey and you can't break/crumble it out of there.
No, you can't weld directly on carbon. You build up the edges, let the liquid bead suck in around it and work your way to the center.
Much easier to do when bridging and filling in a crack or V cut butt weld.
On a good day you can look down the hole and not see where it was joined.
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Re: Welding Cast Iron Block

Post by cgarb » Mon Mar 12, 2018 6:10 pm

The drill wouldn't be unstable, it would be contained with the existing hole, should drill quite well. Provided there is access and it is reachable with an extension drill.

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Re: Welding Cast Iron Block

Post by Keith Morganstein » Mon Mar 12, 2018 8:15 pm

BILL-C wrote:
Mon Mar 12, 2018 12:50 pm
I'm pretty sure that most of the people posting comments aren't familiar with this block and don't know that the passage down the pan rail is a gundrilled full oil pressure passage to feed the piston oil squirter that is supposed to bolt to the missing piece of oil pan rail.
That will greatly complicate the repair. One possible solution that i’ve used on other repairs is to drill, then install a piece of tubing for the oil to flow through. The tubing extends into the “good” sections of the block. On this case another hole will have to be drilled into the tubing for the squirter.
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Re: Welding Cast Iron Block

Post by Keith Morganstein » Mon Mar 12, 2018 8:26 pm

I’d make the repair a “T” shape. It doesn’t have to be symmetrical, save as much good casting as possible. The corners will be drilled and pinned, that will relieve it.
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Re: Welding Cast Iron Block

Post by NXBOY » Mon Mar 12, 2018 11:40 pm

Any of you guys have any experiance with the Certanium 889 sp welding rod. They been used to fixed alot of high dollar blocks with these. I will say they are pretty amazing on cast iron. No preheating, no cracking and fully machinable. I would send a few if ya want to try them.

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Re: Welding Cast Iron Block

Post by Xnke » Tue Mar 20, 2018 5:34 am

If It was my block, I'd send it for powder welding.

But, in the case that powder welding is right out, I'd cut a semicircle of cast iron thicker than I need to do the repair, and use a cup saw in the mill to cut a clean, but rough, semicircle. Then, the area would be heated to burn out any oil and grease that's soaked into the cast, allowed to cool, and a bronze brazing paste applied, then the new repair section brazed into place. Once it's brazed in, the repair line will be thin, and soft enough to not cause issues when drilling and tapping the holes for the piston oiler and oil gallery. When the broken section is as thick as what I can see in the photo, I'm hesitant to try and tig braze something into place, especially if it has to hold full pressure oil.

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