welding a block

Big Shark

Senior Member
Anyone have success welding a hole in the side of a flathead? The hole is the size of a pencil eraser? Thanks Bruce
 
Drill and tap for 1/8" pipe plug if there is room.Why weld if you don't have to. Cast iron can be a real crap shoot unless done by a creditable welding shop get some quotes.Welding would be my last choice just my .02. What caused the hole?

Ronnie
 
Ronnie hit the nail on the head. When I installed 59AB heads on an 8BA block I used a pipe thread tap and then screwed in a pipe plug with non hardening Permatex so it was just below the deck surface . Then covered it with JB weld. That was 10 years ago and it's still holding. I think you could do the same.
 
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How about posting of photo of the problem area. How large exactly and what caused the hole. Never seen a small (bullet hole?) Don't weld if possible. Let's get more infomation first. JMHO Frank pkny
 
My 2 cents...
Wonder why you have that hole- look for cracks around the hole, AND pressure test AND magnaflux the block befor going to other expence... I have a fair amount of respect for brazing on the outside of a block- if you do, try to get the whole block at least warm first... Karl
 
i agree with karl brazing is best but get the block area where you are going to braze warm first this will help :)
 
Theres a special welding alloy rod for it but you only get one shot. Put a holler on the HAMB and see if any of those guys know a local that can show you a bit of his work.
 
As I recall my late ol-school father brazed even pressure vessels of cast iron. He could do pretty oxy-acteylene and stick welds, but he definately was not going for
looks when he brazed cast iron. I think also, that warm was an understatement...more like rosebud hot on the part to be welded.
 
I recently drug out a 59L block I bought from a gent a few years ago. Upon closer inspection I've found a hairline crack on the back of the bellhousing just below the 59. I suspect it may have mounted it an engine stand at one time. Do I need to expect this to get worse? Any suggestions for repair? Thanks Guys
 
Big Shark Bruce: I'd suggest rounding out the hole if need be. Then use either an appropriately-sized metal, plastic or rubber expansion plug.

Burly: Are you sure the hairline crack isn't just a surface casting imperfection? Can you see if it extends to the inside surface?

Jack E/NJ
 
Always wondered how Ford welded the entire sides onto the 1937 V8 60 block. They were welded with one continuous bead around the entire perimeter and the weld was beautiful.
 
I tried a couple of things in the shop Saturday. I took a steam trap (its cast iron), and drilled a couple of holes in it to practice my welding. I tried spray-metal, certanium rod, and a castiron rod. The spray metal would just ball up. The certanium rod cracked when it cooled, The cast rod looked great. Until I pressure checked it. It leaked were the weld met the cast. I think I will try the brazing method. Ill let you guys know how it turs out. Bruce
 
The crap shoot syndrome now begins. You won't get same results with a block if the cast iron properties are different from your test piece.

Ronnie
 
I braze a lot of cast iron printing press parts. Braze works well but you must heat up a large area. The entire block would be best, I know that is not practical. You can ruin the block very easly. I brazed a tractor block years ago. Getting things very hot is important. Yesterday I brazed a cast iron model T muffler end. It came out great. Engine blocks can be tuff , cracking when cool downing. That's why the entire block should be heated. I don't remember exactly what tempeture you need possibly someone else can jump in.
 
An old mechanic/welder near me used to weld up blocks with massive damage. He once showed me a block where he'd nickel-welded about six pieces of cast together that had been knocked out the side of the block in his pickup. It looked like a puzzle, but the engine didn't leak afterward. after seeing that, I asked him to weld the end of my Model T engine block where a 1 X 2 inch piece of water jacket had broken out due to freezing. That weld is pretty. He'd heat the block with a torch before using the nickel rod, and he'd skip around when doing the arc-welding.
 
I had a block about 10 yrs ago that had a hole about 1/2" diameter on the drivers side just above the oil pan rail . The hole didnt show up until the block went through the cleaner . I layed the block on its side and braced it up so the hole was pointing straight down. I then mixed up a whole tube of J.B. weld and kept poking it into the hole then cut a piece of sheet copper and clamped it up overnight. That engine is in a friends 40 and has never leaked a drop after all these years and several thousand miles.
 
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