Welding Steel to Cast Iron Question

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Welding Steel to Cast Iron Question: I am skilled but new to welding, and I am using a Lincoln SP-180 (220v) MIG welder. I have an antique leather bench machine (circa 1881) with a cast iron frame. A mounting foot was broken off sometime and I have made a new foot of 1/2” steel about 1” x 1” x 1/2”.  The cast iron frame is an “L” 1/4” thick where welds will have to be made.  Am I trying to do the impossible? What should I watch out for? Would I be better off drilling and tapping the foot and frame and attaching it with machine screws? Any other suggestions? Thanks.
Reply:Drilling and tapping would be a good plan.   If you have a stick welder and a gas torch, you can pre-heat the casting with the torch and stick weld it with high nickel rod made for welding cast, then 'peen' it with a hammer as it cools, or keep the torch on it for awhile so it cools slowly and evenly.  I've welded steel to cast iron this way and it works good.   If you try it with your mig welder and no pre/post heat, it'll likely crack right next to the weld once it cools.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:I'ld consider brazing it. Plenty of strength, and no chance of cracks forming anywhere.City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:what sort of cast iron is it? if its antique its likely to be grey cast iron so i think you will have to control the heating and cooling carefully. i agree with tanglediver, i reckon you should braze it, but i would still post heat the job and wrap it in a fire blanket to slow the cooling.if it doesn't work you can always clean it up and revert to drilling and tapping
Reply:Thank you for your replies. I'm off to a family reunion this week but will do the job when I return.
Reply:Originally Posted by tanglediverI'ld consider brazing it. Plenty of strength, and no chance of cracks forming anywhere.
Reply:Me toobraze itPeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Me 4, braze it, post heat it, fire blanket itIn the field: '06 Ram 3500/Miller PP350    '14 F-350/Lincoln Classic 300DIn the shop: MM252, Hypertherm PM-85, White face MM200