Welding cast iron.
Turbo Mini Forums

I've got a head I need to do some welding on. Has anybody any experience of this ?
It's not a repair or anything like that, I just need to weld some small blobs of weld into a port. It doesn't need to be neat or accurate in any way, but it does need to adhere and not crack or break away.
I have mig, arc and tig welders.

Phil.

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I'll ask one of the welders at work. But the general gist is grind a prep, pre heat, arc weld with high nickel rods I believe.
Can you not braze it, might be easier?

as tom says really,

I'd look at Tig Brazing it personally, good long pre heat and gentle cool down whatever you do.

I had a welder in nuneaton do my cylinder head when it cracked, he TIG brazed it with nickel rods and assured me that it was the accepted practice. Whether that would suit what you're doing I don't know.

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Definitely not the professional, expert or recommended way, but I have successfully welded cracked cast iron turbo housings with a mig

Cheers guys. It doesn't need to be neat or smooth at all, infact it's better if it's rough. I just need to make half a dozen or so small blobs of weld about half the size of a small pea.

Phil.

WWW.TURBO-MINI.COM

The difference here compared to most other repairs....is most others will not be in a port, with huge potential for risk if it comes apart.

Maybe something to have a specialist welder do ?

And not all cast iron is the same too, although I'd have no clue how to determine what is what

Would you have any old scrap heads to test any welds on first ?

I'd say TIG is likely best option...but I'd nearly be sure pre-heating an slow cooldown would be important to eliminate risk of cracking afterwards

I welded a cast turbo manifold on my Mini years ago after I accidentally drilled a hole in it LOL It welded ok with a MIG but it was a small weld.
Equally I've welded cast manifolds on my V8 for turbo fitment...but these were exceptionally easy to weld, just a nice form of cast iron.

Edited by stevieturbo on 19th Oct, 2016.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

If you wel cast iron with mig the weld and immdediate surrounding area will turn to dismount hard,

if you have broken through a port Phil I'm afraid you may be pissing in the wind trying to weld it up as the feather edge will just burn away,

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Something for you to think about Phil.....?.

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Cheers for all the advice so far chaps.

Phil.

WWW.TURBO-MINI.COM

terrific photo sprocket, nice roughening, but does it work better? curious whether all the extra detail actually outperforms just a roughed out one. - either way the level of skill required is way above my paygrade, so just envious..

I had a head that was broken trough between the inlet and the midle exhaust port if i remember corect. A mate brazed the small holes. Never had a problem with it. Ran the head for 5 years.

No idea on the brazing material but looked like gold ( colour i mean ) or to say yellow copper colour.

Edited by Rammie2000 on 22nd Oct, 2016.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

The problem is when you have to join two pieces of cast iron. When the cast iron cools it shrinks at a different rate to the weld and pulls the joint apart. As stated above, you can pre-heat the whole head so the welds and iron cool slower and more uniformly, or you can weld in short bursts (let it cool enough that you can touch it before each weld).

As you're not actually joining cast to cast, just MIG it with mild steel wire. I've done this when I made a big mistake caving a head. It worked a treat.

I've tried TIG welding with nickle wire and it was a disaster - a waste of a lot of time and gas. I have no idea what happened, but I'm not going to try that again in a hurry.

Brazing is maybe the safer option unless it's an exhaust port ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

How did it go? I''ve got a cast part i'd like to weld/braze onto. I duno if anyones used the site and youtube videos 'weldingtipsandtricks' but he used AC to get some cleaning action.

I've seen on facebook someone laser welding cast heads?

If something is worth doing, it's worth doing half of.