I wonder if plumbing solder wouldn't work. Just wire wheel the crack, gently heat until it will liquify the acid flux paste, then heat a little more until it will melt the lead solder. It should be gentle as far as thermal stresses go. And 200 degree antifreeze should be well below the solder melt point. Since sheet metal used to be soldered by ductworkers as a matter of course in the 30's, then it should work well enough with cast iron too in this low demand application I would think. Don't vee the crack, let it be the wick. Capillary action. Cheap, quick, low stress, semi-permanent. Maybe. Just a thought.
[SOLVED] Welding/brazing diesel engine block Solved
Feb 24, 2005
22 Replies
Now there's an idea! I wonder if solder would "stick" to cast iron. It could be that the galvanized coating allows it to work on some sheet metals. Anyone out there tried this?
John
They used to use lead to join cast iron drain pipe so I think it might work. I have used brazing rod to fix water jacket cracks with great success. Whatever you use you will probably want to drill the ends of the crack. A weed burner works good to heat the block before brazing it. For solder to wick into the crack you would need to clean it so there was no antifreeze or crud from coolant in the crack. Glenn
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