Majorly bummed out. Look at pics
- Thread starter PHANTASM
- Start date
turbodave231
Moderator
- Joined
- May 24, 2001
Cast iron welding
I hate to Highjack this thread, but I was asked about my comments on welding cast iron:
Successfully welding cast iron is certainly possible. But as you have heard it is full of problems and is best left to the expert welders. I've run into plenty of "backyard" guys who claim they can stick weld cast iron with nickel rod.
OK, they can probably make the metal stick together and look OK. If this is in a low stress area of the casting, it might live a full and productive life!! But put this area under extreme stress.......say a main bearing web in a block, and the problems will show themselves.....and not in a good way!
Inspect it with magnaflux or better yet X-ray afterwards and report back!!! Because the localized heat of the weld pool tries to expand the metal around the area, it puts a radial pressure on the casting. The cooler metal around the weld pool doesn't move and if it does, it will produce cracks. The "HAZ" Heat Affected Zone around the weld pool hardens the metal and again promotes cracks.
Preheating is always required for effective cast iron welding.... and when I say preheating, I'm talking 1500 degrees F. Higher than most welding shops can effectively produce for the entire casting. It is generally accepted that a long cooling process and stress relief process needs to follow cast iron welding
Don't misunderstand me, I believe Cast iron can be successfully welded and repaired. But to do it right, It takes an expert with alot of very good equipment and expertise.
Here is a good source to read if you you want more about about the effective repair of cast iron:
Full Torque
We have some pretty darn good welders who frequent this board, Please weight in and let me know if I'm off base with my opinions.
To be constructive to the problem at hand: I think this block can be saved by machining the block and cap on this one main cap for dowel pins. It can probably be done without disturbing the main bore and should not require any other block work. I agree with Rich's comments about the problem: You wouldn't have asked if you didn't know this might be a bigger problem. Fix it now and run the daylights out of the engine without worrying about it!!
Dave
I hate to Highjack this thread, but I was asked about my comments on welding cast iron:
Successfully welding cast iron is certainly possible. But as you have heard it is full of problems and is best left to the expert welders. I've run into plenty of "backyard" guys who claim they can stick weld cast iron with nickel rod.
OK, they can probably make the metal stick together and look OK. If this is in a low stress area of the casting, it might live a full and productive life!! But put this area under extreme stress.......say a main bearing web in a block, and the problems will show themselves.....and not in a good way!
Inspect it with magnaflux or better yet X-ray afterwards and report back!!! Because the localized heat of the weld pool tries to expand the metal around the area, it puts a radial pressure on the casting. The cooler metal around the weld pool doesn't move and if it does, it will produce cracks. The "HAZ" Heat Affected Zone around the weld pool hardens the metal and again promotes cracks.
Preheating is always required for effective cast iron welding.... and when I say preheating, I'm talking 1500 degrees F. Higher than most welding shops can effectively produce for the entire casting. It is generally accepted that a long cooling process and stress relief process needs to follow cast iron welding
Don't misunderstand me, I believe Cast iron can be successfully welded and repaired. But to do it right, It takes an expert with alot of very good equipment and expertise.
Here is a good source to read if you you want more about about the effective repair of cast iron:
Full Torque
We have some pretty darn good welders who frequent this board, Please weight in and let me know if I'm off base with my opinions.
To be constructive to the problem at hand: I think this block can be saved by machining the block and cap on this one main cap for dowel pins. It can probably be done without disturbing the main bore and should not require any other block work. I agree with Rich's comments about the problem: You wouldn't have asked if you didn't know this might be a bigger problem. Fix it now and run the daylights out of the engine without worrying about it!!
Dave
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
I have a block almost just like that. Pete (ANS) told me he purposely knocked those corner chunks off the register (all of them) because more often than not the peices would fall off on their own and end up in the oil pan. This was way back maybe 8-9 years ago.....
Never had any issues with the block in that area. I did crack one of the bores and had to have it sleeved, but no issues with the mains. It's in the car now but I'll have it out in a few days for a motor swap. I'll try to take some pics of it for comparison.
Never had any issues with the block in that area. I did crack one of the bores and had to have it sleeved, but no issues with the mains. It's in the car now but I'll have it out in a few days for a motor swap. I'll try to take some pics of it for comparison.
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
Good move.
Dave......welding cast iron only take SIMPLE welding equipment. A local cast iron welding repair shop showed me how to do it. I have him weld repair cylinder heads that I have gone a little too far with.
1) Grind away the area a bit to expose clean iron
2) Pre-heat to RED HOT with oxy-propane torches placed at each end of an oven that he makes out of fire bricks to accomodate the size of the part.
3) Remove a brick or two to make an access hole to weld into.
4) Use an oxy acetylene torch with a solid 1/2" cast iron welding rod.
5) Keep the pre-heat torches running to keep the part red hot
6) Weld the area with the torch and cast iron rod
7) Replace the fire bricks and let cool for a few hours
8) Quickly remove part from the make shift oven and wrap with thermal blanket, lay on floor (carefully) and immediatly bury the part with a BIG pile of sand.
9) After 24 hours of slow cooling, shot pean the entire part in a steel shot blaster.
10) Re-machine all areas of the part. Done.
Simple tools and equipment, but very time consuming. He has weld repaired some terrible damage and it comes out perfect. You can't even tell it'e been welded. BUT.......that is the ONLY thing he welds. I may have missed a step or two, also. It's been 10+ years since he showed me how to do it.
I have welded cast iron with a TIG and stainless rod. Stainless and cast iron have similar heating and cooling characteristics. Similar is key word here. I have also used silicon bronze to repair a gouge in a cylinder head deck on an FE Ford for a local machine shop. Worked great.
The only other feasible option would be to weld a bead on the edge of the steel cap and re-machine the register in the block to accomodate the wider cap. (after machining the welded cap edge)
