SWMBO's Korean tintop has developed a small crack in the exhaust manifold - you can hear it on a cold start but it closes up as soon as the engine is warm.

I just called the main stealer and the price for a new manifold (which has a welded on cat) is over £650 !!

Needless to say I am looking at ways to repair the crack - any ideas guys? I heard of a epoxy putty used to repair boilers but can it be welded?

would exhaust gunk not do the trick?

I qualified as a PCN Mag particle inspection tech today That would find the extent of the crack.



You could then get it welded.

They can be brazed or tig welded with the right rods. I used to work for someone but he is in croydon.
If you can get it over to him I'm sure he'll do it. Preferebly off the car.
Alpha Welding 020 8684 3811 Alec

[Edited on 18/6/2010 by nitram38]

arc welding works i'm told

Thanks for the offers guys. It is her daily driver so I really need to do a quick bodge ..... er ... repair for now. I would really like to get it done properly when I can take it off the road for a few days.

You will find it needs heating up before welding and then checking, then heating and welding over and over as the crack can return.
The rods look like a soft bronze colour

I``ve welded using arc a cast manifold to mild steel.
It worked vey well, and that was with standard rods.
You need to use 2.5mm+ rods, designed for cast, as high power without melting holes. I used 100 - 120A.

The higher heat and penertration is the reason it works better than wig would.

Darren

Hmm a Hyundai by any chance!
I thunk my dad had it welded and when you bolt it back on it twists and cracks again, maybe reskimming could stop this tho.

We cured it in the end using said above Boiler Assembly mastic that's rated to over 1300 oC
usually made by Pyrma? I think and about £10 a tube.
Just cleaned up the manifold with it still on the car and smeared as much sealant in as we could with our fingers and an inspection mirror.
We let it dry, fired the car up so it really dried out and then when cold again covered the mastic in silver flue
tape to try and prevent it getting wet.

Did the job for a good 3 years 20,000 mile till the car was scrapped suppose we should have kept it now lol

you can arc weld it, but really heat it up with a blow torch beforehand ( i mean red hot) and then after welding keep applying heat so it cools down gradually, i've done a couple like that and also repaired cast iron guttering the same way

This method works well, i used to work for a company that repaired heads and manifolds and we would heat up till really hot then weld it and after welding we peened the weld with a ball pein hammer then buried it in sawdust and left overnight to cool.We used Eutectic cast rods which are a high nickel content and had very few failures, as mentioned above you do need to check it is flat after welding as if distorted it will cause it to crack again.
Paul

quote:

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Originally posted by rpm
you can arc weld it, but really heat it up with a blow torch beforehand ( i mean red hot) and then after welding keep applying heat so it cools down gradually, i've done a couple like that and also repaired cast iron guttering the same way

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Ive MIG welded cast before. Makes a bit of a mess, but it is possible at high power and fast wire feed.

I have the same problem on my tintop. I jsust filled it with exhaust putty. Its been there 4 months now

If it is cast iron, use monel metal arc rods as previously described

If cast steel, you can mig with a good level of success. Even better, drill out 5mm holes either side of the crack, tap to M5, grind out a channel between the tapped holes, place M5 setscrews in the holes and mig the screws along the channels to make a stitch, the cooling with draw the crack together and seal it.

iv done loads of transit ones,drill the ends of the cracks and use an arc welder....simples