hi can someone tell me how to repair a broken (iron) casting, there is no stress on this item,purely cosmetic, weld .braze etc, thanks in advance, john,

superglue, araldite?

Cast iron can be welded.

JB weld.......

Is it the rhones or cast guttering your on about?

A very good clean with the wire brush and tack weld it together .
Then mig it a short section at a time making sure its hot all over the piece.
If you go too fast it cracks ......

its actualy a garden trough similar cast to guttering. ile give mig a try,thanks all.

You should really heat the piece up very hot, weld it then pack it in (fireproof) insulation and leave to cool for days.
Brazing is much more kind and safer.

For cast i thought Mig wasn't good - heat too concentrated so that area expands and contracts too much. Thought Arc was much better, esp as they do rods for cast (but this may also need pre-heat, no idea as i've never done it).

get the good old sticck welder out make sure you heat the item prir to welding or the cooling process can stress the repair

I welded some pig iron with some "cast" welding rods in a bog standard stick welder. First blast it with a gas blow-torch so you get it nice and red around the crack (in my case). As said, let it cool REALLY slowly - stick in an oven if at all possible.

As said use proper cast rods (not cheap!) & if you can warm the whole area up a bit then it does help with the thermal shock. Another thing to do is weld it in short sections, about an inch at a time & tap the weld as it cools for a few seconds with a blunt chisel then weld another inch or so. Welding in short bursts then waiting 15-20 seconds stops too much heat build up & the tappin relieves the stresses apparently.
If it's got a side that is'nt seen & so does'nt matter cosmeticly then you can weld some strips of mild steel across the join if you want to help tie it together, the cast rods will weld the two together.

I welded a cast iron fire place back together when it split in two while removing it. I arc welded it using cast rods, welded up a treat even though it was a five foot weld, I welded it on the back side and as it welded it pulled the join tighter and tighter until it was invisible on the front

I welded cast steel with a mig no problem but when I tried to weld cast iron it made a real mess

Cheers
David

cast rods or dis-similar, heat prior to welding and it'll be less likely to crack

Pre heat till red use cast rods 90% nickle if you can afford them and let cool slowly also dont forget to gring a good prep on it (v groove)

thanks all. stick it is,,

pre heat and weld with stainless (non mag type) or braze with mig or gas

your weld will just crack off if you just weld it normal