Welding a Yanmar block. HELP

[davecharles]

Thank you for the replies. Looks like a trip to the machine shop to get a bid. If I can afford their price I'll have them weld it. If it's too high I'll use $5.00 worth of epoxy.
Dave

 

[yomax4]

Find someone with a spray powder torch and spray it up. Simple and will never crack or leak.

 

[Danno1]

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Braze it. It will be fine.



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[Mark @ Everlast]

I would braze it as well. I don't think you'll need to strip the block. You only need to heat the local area for brazing usually, having made a few brazing repairs like this myself. Make sure you use some fresh flux or a fresh brazing rod with flux. Clean it up as good as possible though around the crack and follow all the normal prep procedures like drilling the ends of the cracks. Use a magnyfying glass and plenty of light to make sure you are at the crack's end though.

 

[flusher]

I'm in the middle of a complete overhaul on my YM240 Yanmar. I was cleaning the block getting ready to install new liners, pistons, rings etc when I found a crack in the block (water jacket) below the water inlet. The horizontal crack is about 3 to 4 inches long. I know to drill the ends of the crack and clean out the crack. I need to know who has successfully welded an old Yanmar block. I have a mig welder with 75/25 gas or 100% helium. What wire is best on the iron? Any tips would be greatly appreciated. I am a novice welder. If it is too difficult to weld I can take it to my local machine shop.
Dave

I welded a flange that had broken completely off of the block on my 1948 Farmall Cub. Used a Hobart LX Stickmate welder and Super Missile rod (1/8" dia, DC+, 100 amps).

You need to grind a V to clean out the crack and drill the ends of the crack to keep it from propagating.

Use short welds (3/4" or so) to keep the cast iron under about 300F. I use a cheap IR thermometer from Harbor Freight. Let the material cool back to room temperature before running the next bead. Start at one end of the crack. Then the other end and continue this type of skip welding until you reach the middle of the crack.

You need to use a welding rod/wire that's good for stainless steel (rod has a high nickel content).

https://www.youtube.com/watch?v=JwF4iYgkd0U

https://www.fastenal.com/web/products/details/0857244

Good luck.

 

[Arc weld]

Stainless rods and nickel rods are 2 different things and although I like Lanse, aka Chuck, he is not the one to go to for advice on welding cast iron.

 

[Jesse masterson]

I hate to say this but I have had so good of luck with jB waterweld I would try it first.it hasn't failed me in a application yer it is a putty that dries rock hard and bonds to nearly everything, the old me would have welded it but his stuff is so good I would try it first!!!!

 

[gordyy]

little late to this party, but check with an old implement dealer or mechanic the old farmalls and IH tractors used to develop cracks all the time with loader use. They drilled tapped and installed tapered cast-iron plugs then drilled and tapped right alongside of them and put the next one in with a half moon drilled hole thru the one before locking it in place and grinding it flush. have a couple of 6.9 fofrd diesels crack alongside the freeze plug hole where the soft plug heater went, did this to 2 of mine and another one for someone else. don't remember what exactly they called them but at the time got them from and IH dealer put in the plugs last one partways into the freeze plug hole then ground it out and put an o-ring sealed plug in the hole. They both held for over 250,000 miles one engine is in a grain truck now I think there is close to 38yrs and 400,000 on the block repair.