Cast Iron Manifold

[oldcorollas]

actually.. "rust" does refer to iron oxide specifically.
iron based materials can rust, IF the iron is the component that oxidises.

for example, stainless steel is iron based, with nickel and chromium typically.
the chromium oxidises naturally, but you can't see yellow stain, so it is not "rusting", but when the chromium gets depleted, the iron starts to oxidise, and you see yellow/orange stains, and you say the stainless steel is "rusting"

a chromia or alumina former does not "rust"...

when you see aluminium being oxidised, you don't say it is rusting......

all metals do oxidise. gold, platinum and palladium also oxidise under the right conditions. the difference is that the oxide layer is very thin and is dense and protective.

platinum oxide vapourises too (ie has high vapour pressure), so you can't use it to suspend samples when you oxidise alloys around 1200 or 1300C it is ok in vacuum tho...

[hypo23]

yes you can weld it ive only done it a handful of times though, you can get cast iron electrodes, they are not cheap though as packet of electrodes works out to be about $4:80 per electrode, they are not an easy rod too weld with, and yes its best to give it a bit of pre heat with an oxy and peen your welds as soon as you do a weld while its still hot to prevent them from cracking

[The Real Roadrunner]

the rods in question are a high nickel content rod and only available for ARC welding, but you can knock the flux off them and use them for filler rods with TIG if your after a better finish.

but for the cost of a new head flange i know which way id go.

cheers
linden

[clubagreenie]

You can get rods called weld alls (what lindens referring to????) Used often to weld under water (wrap in electrical tape, scape off end when under). Will join pretty much anything to anything. You just have to trial and error for strength but I have welded cast to stainless before. But as mentioned there are specific cast rods as well.