welding a block

Paul in CT wrote >>>J.B. Weld ?? Nothing to lose.>>>
Then Ken/Alabama wrote >>>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.>>>

OK, Big Shark. After carefully considering all the suggestions, Paul's & Ken's seemed best to me.
And if JB Weld doesn't work, then you can try Ronnie's, 19Fordy's & Ol' Ron's suggestion of rounding out the hole with a drill and simply plugging or tapping for a threaded pipe plug.
Then if all the above nothing-to-lose fixes don't work, then you can try the more risky almost everything-to-lose fixes.
Those are my opinions, and I'm sticking to them. 8^)
Jack E/NJ
PS: I think Sturgis 39 had some words of wisdom that might well apply to your situation --- "if it can't be fixed with bailing wire, JB Weld or ducttape, it can't be fixed."
 
To weld cast iron the metal needs to be at least 400 degrees F iirc. Check with the welding rod instructions.

Many years ago my dad helped a friend rebuild a 100 ton punch press with a cracked bed. They took it to a heat treater who spend 2 days bringing it up to temperature, my dads friend welded it (sucessfully), then 2 more days cooling it. Heating/cooling too quickly could have warped or cracked it more.

Best bet is if it needs to be welded find someone with the experience to do it right (or plan on practicing on 200 or so junk pieces to get your technique right).
 
If the crack/hole only needs to hold cooling system pressure, JB Weld it. I've done a number of engines with it, and it held great...none ever let loose. The MOST important thing is surface prep. Clean, clean, clean! Second choice...drill/tap/thread in a plug. Third choice...braze. Fourth choice...another block. LAST choice...weld...
 
Yes the cast part has to be preheated or when the hot electrode is placed on the frozen iron the alloy thermal shocks at the contact point and leaks. In practical theory all welds are best when the components are heated to reduce the thermal or shrink shock. When you heat a clean peice of cast you can watch the temperature chase the moisture out of it, if you apply an electrode directly to the cast part it will not do that, it traps it causing cracks and inclusion. The big problem with welding your block is that you will have to find just the right alloy to do it. Might need a junk block to learn on. Evenly warming a block uniformly should not damage it, it most likely gets hotter than that in some places during use and hat would be a non uniform heat. You get the best result if you temper cool the repair on the way out of heat, gradually reduce the temp over time in a controlled environment, turn down an oven over time. It would be a fun thing to play around with on a block, I've done a lot of cast iron stack brazing, we call it brazing though it's not, however plumbing cast iron is truly garbage in comparison to an auto engine block. For this I used a Ni Rod stick SMAW process, preheat the rods to 500 and the stack fitting to 500. On junk cast it's like welding a styro foam cooler, it foams and gets all goofy. How much pressure is in a flathead block that you are looking to hold back? I use a product called crack stick on thin cracks, it holds back a pound or so of pressure. You have to clean the surface well apply it hot and work it deep into the crack.
 
yeah 400 degrees is good...oxy weld it and then place it in a sand box for cooling the sand traps the heat and gradually cools it down...a large welding shop should be able to handle this no problem
 
Cold fix is best if possible. If the hole is from corrosion, drill it till you have sufficient thickness to tap for a plug with Locktite - or talk to your welder about Muggy 77 stick rod for cast iron repair.
 
Big Shark wrote>>>Muggyweld? Comments?>>>

I think JB Weld should be the first thing you try. Followed by some type of aforementioned plug. Last, any fix that involves heating a big hunk of cast iron.

Jack E/NJ
 
What is the intent of saving this block ?

Do you have $$$$ ******* in machining ?

Rare block???

Let us know WE want pictures.

Ronnie
 
Welding cast iron can be an interesting challenge. A restrained joint condition, such as the middle, side of an engine block, can be the more difficult to deal with. There are two basic procedures commonly used. The first is what can be termed "cold welding". This involves using a very ductile stick electrode with absolute minimum heat applied and followed with immediate "peening". The weld actually looks like a series of very short spots, each of which have received serious peening. There is plenty of cooling time allowed between the application of each weld "spot" and the temperature of the weld area is never allowed to become uncomfortable to the bare hand resting on it. It is best to have 2 jobs going on at the same time so you can weld a "spot", peen for a minute, go to the second job for 30 minutes, return for another round of spot and peen, etc. etc. A highly restrained joint can survive best if "buttered" all around with your ductile filler rod before attempting completion or closure of the crack or hole. In other words, the final weld spots should not join 2 sides of cast iron, but rather, couple 2 sides of filler rod.

The second method for welding cast iron involves using a large furnace where the block is allowed to "soak" so the core termperature is maintained at a high level. For spray welding the core temperature should not drop below 600 degrees. This means it is sometimes necessary to either return a partially welded item to the furnace or apply some of the welding while the part is in the furnace. As you might guess there can be some discomfort for the operator. Some procedures require 1000 degrees, or more, to safely weld cast iron. The welding is followed by a strict cool-down procedure which can take 2 or more days.

Welding of non-restrained joints in cast iron can be as simple as welding steel. But, any restrained joint condition can set off a series of unpleasant happenings when welding is done.
 
I've just found a similar issue with a 59 block I was planning to use. I had it checked by a shop for cracks, it was supposedly OK, then the same guy did all the machine work for me. Well that was about four years ago, my project is finally getting to the point that I wanted to start putting the motor together, so I'm cleaning the water jackets with evaporust, and notice a wet spot at a point that I thought was a casting flaw.
Well it's not, I just pressure tested it and it is definitly seeping out this spot, slowly at about 10 psi. It takes about 10 minutes to get down to 3 psi.
The black spot in the center is actually the evaporust seeping out.
It is about the size of a dime, on the rear oil pan surface.
So my question is, Why can't I drill it out and put a welch plug in the hole? It would be hidden mostly by the pan. What do you guys think?
 

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Yes, you probably could, but you would need to drill the hole very accurately to get the right sort of interference fit for the plug.
If it subsequently leaked, water could get into the sump so it is pretty critical.
I'd be tempted to drill out to the tapping size for a pipe plug - say a 1/4" plug, that's just over 1/2" outer diameter - then see if there's plenty of meat there, if so, tap it, fit a plug and grind/file it smooth - if it's still a bit flaky when drilled to that size, drill to the next size up and fit a 3/8" plug.

That should be a relatively cheap, quick and easy fix.

Mart.
 
I had a hole in the side of my block. Took a punch and chipped out around the hole to be sure I got to solid metal, then rounded it out and put a 1/8 " pipe plug in it and it hasn't leaked a drop yet. Easiest and best way to do it IMHO.
 
I know a machinist that could drill an accurate hole, but if I can do it myself with pipe plug it would be better. There is plenty of area around the spot before I get into any of the sides of the block, so I might even be able to go 3/4" plug if needed.
 
There's no need for either of these methods if any kind of electric welding is done it should be done with a tig welder not a stick welder or spray welding. Maybe 40 years ago you could do this but even then it's a long shot. Honestly it shouldnt have even been brought up. Every machiniest I know has told menallmblock cracks get fixed using oxy-acetylene or a tig welder in similar fashion with headting the block and a sand box cool down....now that's nearly 30 guys in the local machiniest society we all had breakfast this morning. So if you're going to weld take it to someone who knows what he's doing

JWL said:
Welding cast iron can be an interesting challenge. A restrained joint condition, such as the middle, side of an engine block, can be the more difficult to deal with. There are two basic procedures commonly used. The first is what can be termed "cold welding". This involves using a very ductile stick electrode with absolute minimum heat applied and followed with immediate "peening". The weld actually looks like a series of very short spots, each of which have received serious peening. There is plenty of cooling time allowed between the application of each weld "spot" and the temperature of the weld area is never allowed to become uncomfortable to the bare hand resting on it. It is best to have 2 jobs going on at the same time so you can weld a "spot", peen for a minute, go to the second job for 30 minutes, return for another round of spot and peen, etc. etc. A highly restrained joint can survive best if "buttered" all around with your ductile filler rod before attempting completion or closure of the crack or hole. In other words, the final weld spots should not join 2 sides of cast iron, but rather, couple 2 sides of filler rod.

The second method for welding cast iron involves using a large furnace where the block is allowed to "soak" so the core termperature is maintained at a high level. For spray welding the core temperature should not drop below 600 degrees. This means it is sometimes necessary to either return a partially welded item to the furnace or apply some of the welding while the part is in the furnace. As you might guess there can be some discomfort for the operator. Some procedures require 1000 degrees, or more, to safely weld cast iron. The welding is followed by a strict cool-down procedure which can take 2 or more days.

Welding of non-restrained joints in cast iron can be as simple as welding steel. But, any restrained joint condition can set off a series of unpleasant happenings when welding is done.
Click to expand...
 
Are we done yet ???

Jb weld,tigging,ni rods,Grampa's oxy,my uncles spray weld,pipe plugs.
 

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