Welding a Kettle

The wire you used was the wrong type for cast iron. I believe when you mentioned "flux core", you were referring to E-70 or 71 TGS or something similar.

The problem you experienced on the inside of the kettle was due primarily to contamination. When cast iron is heated, the material it is in direct contact with will seep into the porous grain structure and can be difficult to counter. Contaminants are removed by boiling them or burning them out, by grinding, by sealing and burning as with an exothermic electrode, or by chemical wash.

I would not agree that cast iron is unweldable by electric arc. The type of cast iron in these kettles is particularly difficult to repair for more than one reason. I have repaired them using the exothermic electrode followed by a "high quality" SMAW electrode of proper chemical composition. A powder welding torch works well also. The SMAW or even GMAW process is sometimes the only viable method (for cast iron repair)in cases where the base metal mass is great. I don't believe that any one process is the catch all.

Glad to hear that someone wants to learn to

weld cast properly . the terms arc weld and cast

iron should never be used together ( not

compatable ).

Airco used to make cast rod for torch but no

longer does , harris is one of the few that still

makes it.

You will need the rod ,the flux ,a small torch

with which to weld , and a large torch to preheat

the work,( propane weed burner works well ).Heat

large area of the kettle to dull red ,this gets

past all of the expansion so that when it cools

that base metal and the weld will contract evenly.

That can not happen if welded with nickel,because

nickel has about 3 times the tensile strength and

a much greater rate of expansion than cast iron.

Maintain the preheat while welding and when

finished welding do a post heat to a slightly

higher temperature to stress relieve and wrap

in asbestos blanket until cool ( 10 to 12 hrs).

george