Amongst all the stovie clan out there there has got to be someone who has good imput on how to repair cracked cast iron. I am particularly interested in cracks in older type cast iron pot rings. Would they take a small weld from underneath without a risk of additional damage? Since they heat up pretty good I don't think they would take any sort of epoxy repair. All ideas are welcome. Gordon
Gordon Welding cast iron is not really a job for an amateur. To weld it sucessfully It has to be heated to red heat, special rods used and allowed to cool slowly over a few hours or it will crack again beside the weld. It's more sucessful with thick castings. With something as thin as a pot ring I think it may be a no no. There are rods that will weld all metals but the weld ends up a different colour to the parent metal. It is possible to brass braze cast iron but then you get the same difference in colour. Bet that's cheered you up. Henry
I worked in the Aerospace industry for years and the favourite (and only certain) way of repairing cast iron that the welders used, was brazing using 'Sifbronze'. Regards: Jim Ford
What has to be done in prep for the brazing? Does the work have to be preheated? Is there any sort of flux used, etc.? What are some sources for sifbronze? Thanks for the response stovies. Gordon
Albert did a welded repair for me, rebuilding a top ring from a handful of jig-saw pieces, by welding. I repaired a crack by filing a groove into the crack to get a clean surface, fluxing with borax and using a brazing rod from my local tool supplier which claimed to be suitable for cast iron. It was just OK for the Bernzomatic brazing torch I have, with MAP gas. Different colour metal but OK viewd from above..
Hay Murray how did that pot ring go ? Did the welds hold up ok. or Did it crack again, I hope not Gorden I would say epoxy repair would be out. Weld or braze would be the only way. Realy you have to heat your job, just under red. Weld. If you are taking too long you, will have to stop, heat again, then start welding again. The problem is not only where you are welding but the expansion or contration of the metal even 3" or 4 " away will crack. Cooling , Well I am told you should put it in lime and let it cool as slow as posable. Too fast and it will crack. It is really bad stuf to weld. All the above aplies with brazing as well. Good luck. Do you want a new one. I have them
