JB weld or epoxy or grout 8ba block

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grovesmr

Senior Member
Sorry for the click bait. I don't really want to entertain such options. Unless someone really experienced tells me I have no reason to make my first attempt at cast iron welding. I'm not going to listen to anyone telling me to take it to someone else. That's entirely how I forever avoid ever learning something new.

I have quite a few hours with stick and might, but no cast iron. I'm not gonna jump on this first go, I'll go digging for something rusting away if I don't find a cracked piece I'll make a cracked piece.

Now onto the block in question, it's not exactly cracked, it's chipped on the front left corner. I'm not sure how such damage could have happened, maybe someone got crazy using an impact to drive the water pump bolts in, maybe freeze but I've been all inside the block getting it cleaned and can't find anything else(hasn't gone for checking yet)

My delima is that more that half of the bolt hole still exists, there fore it seems like it should have some amount of torque capability, enough with the others being perfect? I don't know. The chip isn't through to the jacket but it's thinner than I'd like.

I'm trying to talk myself into welding this up instead of epoxy type solutions. I have access to stick so I'd use nomacast rods or nickle 99 rods, also have a crappy Chinese mig, but I'm not going to buy a roll of nickle. Also have a really old Miller 320a/bp but while I'm hopeful, I'm not sure it works. I've been looking for a reason to get grandpa's giant ancient Tig running again. If it didn't weigh as much as a 88 Honda Civic I'd have probably moved it already to the 220 outlet I ran for my compressor and baby welders
 

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Maybe clean the threads up and screw a stud in just snug. Then weld in from there? That is a big chip!
 
Perhaps to fill space entirely with epoxy. Then once hard and cured, relocate stud hole position, drill and retap. Once completed and waterpump refitted should hold secure with load spread over all securing bolts. Thats what i would attempt first.
Phil NZ.
 
I would not be inclined to weld on a block with that type of damage. If it is a good block otherwise it would sure be easy to cause more damage that you solved. Looks like a good candidate for epoxy to me.
 
37 Cab said:
Maybe clean the threads up and screw a stud in just snug. Then weld in from there? That is a big chip!
Click to expand...

I thought of the stud idea but that was with epoxy. If I weld I'd fill and retap.id experiment first but nickle should be machinable.

It's a big chip but seems like it far away from anything vital. It just barely reaches the head mating surface. Id almost say it's a mostly cosmetic repair. I just wanted to figure out what to do about it before I take the block somewhere to get bored and seats ground or replaced.
 
Cionsdiering the location and your interest in learning and if it was me I would try welding the area. Checking on Youtube theres an interesting video on Tig welding iron. The repair needed on your block would be perfect for the Tig welding repair.
Ronnieroadster
 
I have been tig welding for 30+ years and can tell you that without some considerable test and seat time your attempt to weld and machine cast iron with any sucess is marginal at best.If you don't have the broken piece it becomes more of a problem as it will take a large amount of heat to build it up and it is the heat and proper insulated cooling that will give you grief if not followed correctly. Feel free to jump on it but remember in general for a successful weld repair with what you have stated,and cast iron welds on engine blocks have been well noted to be a crap shoot at best by the average home welder. Just have a conversation with a weldor that has some cast iron engine welding experience to get as much info you can. You may find someone that will take it on no harm in asking.

R
 
Here is another avenue to consider you have to get it extremely clean get a stud that fits the bill install it and and have someone tig weld down the sides with silicone bronze you don't have to bury it in bronze just weld down each side and it should be a better attempt than nickle rod and machining.

R
 
Epoxy it. Coat a bolt with coppercoat/antiseize compound and screw it into the remains of the female thread. Mix and apply your epoxy of choice. When cured you'll be able to unscrew the bolt, courteousy of the antiseize preventing the epoxy from adhering to the thread, and dress it all up externally so that once painted, it'll be indistinguishable. As you said, it's only cosmetic
 
JSeery said:
I would not be inclined to weld on a block with that type of damage. If it is a good block otherwise it would sure be easy to cause more damage that you solved. Looks like a good candidate for epoxy to me.
Click to expand...

You just don't want me to ruin a virgin block, admit it.;)

It's going to need the seats kissed at least, storage under a questionable roof for decades in the the humid Midwest directly across the street from a street plant and the crap they throw in the air, the slag pit is behind the the shop. I'm surprised it wasn't worse. Bore seems to be stock depending on the accuracy of my micrometer.
 
Doesn't look too critical to me. Doesn't take a whole lotta torque to satisfactorily snug a pump & mount at that spot. Use a stud if you're afraid to torque a bolt. Is kinda ugly though. I'd probably hafta fill it with something so nobody would notice. Jack E/NJ
 
grove,
Consider drilling the hole deeper, even into the water jacket. Get a 3 thread
lead tap and tap thru. Install a 3/8 -16 stud glopped heavily with DEV CON epoxy and screw it into it's new home.. Before things start setting up grab a water pump housing and wrap it with a cheap plastic bag. Install the pump and fill the broken out area with more DEV CON. If the plastic bag does its job the pump housing will separate the the good as new block with a minimum of blood sweat and tears. FYI...DEV CON is JB Weld
on steroids.
OMHO
Charlie ny
 
Ronnie said:
I have been tig welding for 30+ years and can tell you that without some considerable test and seat time your attempt to weld and machine cast iron with any sucess is marginal at best.If you don't have the broken piece it becomes more of a problem as it will take a large amount of heat to build it up and it is the heat and proper insulated cooling that will give you grief if not followed correctly. Feel free to jump on it but remember in general for a successful weld repair with what you have stated,and cast iron welds on engine blocks have been well noted to be a crap shoot at best by the average home welder. Just have a conversation with a weldor that has some cast iron engine welding experience to get as much info you can. You may find someone that will take it on no harm in asking.

R
Click to expand...

Thanks, while I'm self taught, with lots of self research i wouldn't say I'm the average home welder. I started with sticks or I guess smaw and resisted going to mig for a good 4-5 years. I don't claim to have anything like your experience but I do have some control, enough to weld thin 90's Honda sheet metal with a stick cause I didn't have the money for nice equipment way back then. Tig and or cast iron might well be another beast entirely for sure. But I do have some experience with keeping heat out of the parts.

Before id tackle this I'd find something to practice on first, it'd be cold welding because one I don't have a reasonable way to get the block to temp, and two, it's not an area that should be in any stress. Very small welds, slowly building up the area, maybe even over a few days. I think I could keep a temp shock out of the equation. All this spot needs to do is hold the last 1/4 of the threads of one bolt to the water pump.

I would love your recommendation of filler rod for Tig or sticks for smaw. Thoughts on nomacast, ni55 or ni99? Something else entirely? Polarity? Even if it's hell no JB weld is perfectly fine for this application, that's exactly what that's made for

I do value your experienced opinion to not touch it and leave it to the other guys, I'm just not built that way, I think that's the problem with my peers, I'm gonna get my hands dirty, I'll **** up along the way, hopefully just on practice parts and I'll learn something along the way
 
Charlie ny said:
grove,
Consider drilling the hole deeper, even into the water jacket. Get a 3 thread
lead tap and tap thru. Install a 3/8 -16 stud glopped heavily with DEV CON epoxy and screw it into it's new home.. Before things start setting up grab a water pump housing and wrap it with a cheap plastic bag. Install the pump and fill the broken out area with more DEV CON. If the plastic bag does its job the pump housing will separate the the good as new block with a minimum of blood sweat and tears. FYI...DEV CON is JB Weld
on steroids.
OMHO
Charlie ny
Click to expand...

Devcon came up in my research and marine Tex as well, most of my research ended up with failed videos of JB weld or epoxy fixing giant cracks in the side of blocks. That's why I came here with the pic, this damage seemed like a good candidate for a lesser repair until I started researching.

Also came up with a grout of all things. I can't remember the name I came up with it's bookmarked at home. Apparently cement type materials have similar expansion rates as cast iron.

In all my research I just didn't find the type of repair this ugly chip seemed to be so I'm trying to figure out the best way to tackle it myself, with some words of wisdom from y'all, of course.
 
One of the concerns I would have is the block deck surface. It may very well require resurfacing after applying than much heat to a corner of the block. At the least it would have to be checked.
 
JSeery said:
One of the concerns I would have is the block deck surface. It may very well require resurfacing after applying than much heat to a corner of the block. At the least it would have to be checked.
Click to expand...

For sure, I'm not about to rig up something sketchy even in grandpas quite sturdy drill press. Drill press doesn't express the right picture,

This thing is huge, with some more experience I might feel comfortable making a fixture for cutting bores. But truing up the block will be something, one of the very few I'll be outsourcing.
 

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40 years ago I had a similiar problem and used nickel rod for cast iron. Turned out fine and is still holding but I had the missing piece and it wasn't a critical machined surface. It was a personal challenge. In your situation I would find an old piece of cast iron and practice weld first until I felt comfortable. Screw in a correct length or "All Thread" stud, preheat, then weld short bead, peen as it cools down. Your welding will hold the stud. Repeat the procedure. No doubt, if it gets too hot, the machined surface for the head could warp. Check it with a straight edge. also check cylinder bore. Go slow.
 

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It´s an ideal place for welding since there will be no built in tension when the weld cools down.
Get machinable rods and stickweld it.
Take the time it need !! don´t rush it will take a lot of time to get done right !!
Go slow a little at the time and let it cool down between.
Saving the hole...i would probably just drill it and put in a timesert when done..
 
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