Welding crack in cast manifold?

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The conquest won't run really well because it has a crack in the turbo manifold. I got a spare from a friend and his has surface cracks.Friend told me that I should pin each end of the crack. So I did.The said to heat it until its cherry red and I can mig weld it.Will my Hobart 140 handle this job?Talked to my dad and he recommended to stick it with his max star or tombstone with nickel rod or braze it.What do you recommend and am I missing at steps?Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Pinging the ends should be ok. Better to drill a hole on each end though. Use nickel stick rod. Heat it up to about 350 and run a bead. Grind it off smooth and look to see if the crack got longer. If it didnt your goog to go.My hood and I... Till death do us part
Reply:1st post. I've done lots of cast iron manifolds through the years. That said some are repairable some ain't. If the outside of the mani where the crack is looks like alligator skin it's a long shot.  Nickle rod is the way to go, drill each end of the crack with 1/8" bit or less, V out crack about 50%, preheat a bit and lay about 1/2" bead of nickel then peen it with the point of your slag hammer. The idea is to spread the weld a bit, lay another 1/2" and peen, etc until finished. Cool slowly.
Reply:The manifold should be cast steel not iron.drill 1/8" hole at end of cracks. V bevel half thickness. Heat it to 600* let heat dissipate through it, when around 400* weld it up, heat back up to 600 and let cool slowly. When around 200* anneal peen the weld..... That's how I do it.... Never had an issue with one... Good luck.Last edited by astaindsoul5446; 04-06-2012 at 10:17 PM.
Reply:To Start with, what conquest runs like it should, not many. Anyways on the manifold, i have welded many and have always have had good luck using the nickel rod, V'ing the crack , heating to around 600 700 degrees and welding around 300 to 400 using a laser thermometer heating it back up to around 600 700  and letting it cool. Also i had them bolted to an old head to help with it warping as all the ones i have done have been releif cut.