re. Exhaust manifold welding tips + ceramic coating

Orin Eman orin@drizzle.com
Fri, 6 Sep 2002 12:37:16 -0700 (PDT)


Check out posts on welding cast iron on the welding newsgroup,
sci.engr.joining.welding.  Pre-heat, nickel filler and _slow_
cooldown seem to be the keys...

Orin.

> Martin Pajak welded my manifold up for me about six or seven months ago and
> it is still holding up fine.
>
> On the first attempt to do a mig weld, we were getting a very unsatisfactory
> looking weld so we used a barbecue to heat the manifold prior to welding. On
> the second try with the heated manifold, the weld was excellent and flowed
> smoothly from new material to original casting with an almost imperceptable
> change in appearance. It turned out looking 'picture perfect' and has held
> up much better than my head gasket (blown twice now) on this engine.
>
> Perhaps the uniform pre-heating of the manifold is the way to go on this
> kind of repair.
>
> My $0.02 cdn.
>
> Cheers!
>
> Peter
> 1990 200Q MC2
> 1989 200Q MC1 parts
> 1987 Coupe GT 2.3
>
> > -----Original Message-----
> > From: quattro-admin@audifans.com [mailto:quattro-admin@audifans.com]On
> > Behalf Of Aaron Gibson
> > Sent: Friday, September 06, 2002 2:49 PM
> > To: bswann@worldnet.att.net; antar@attbi.com
> > Cc: quattro@audifans.com
> > Subject: Re: re. Exhaust manifold welding tips + ceramic coating
> >
> >
> > I had a local welding shop fix my cracks and they used a nickle
> > welding rod.
> > They also would weld a small bead and let it cool and then weld
> > more etc etc
> > etc. Its holding up very well so I guess nickle rod is the way to go.
> > ----- Original Message -----
> > From: "Ben Swann" <bswann@worldnet.att.net>
> > To: <antar@attbi.com>
> > Cc: <quattro@audifans.com>
> > Sent: Friday, September 06, 2002 12:54 PM
> > Subject: re. Exhaust manifold welding tips + ceramic coating
> >
> >
> > > I'd be interested to know what you find as I have 2 manifolds here with
> > tiny cracks.
> > >
> > > I was tempted to try brazing as that may allow for some flex.
> > >
> > > My understanding was however that if you weld it, then it needs to be
> > planed so that all of the runners are flush.
> > >
> > > Ben
> > >
> > >
> > > [Even though I'm probably going to trash my manifold, I tried to weld up
> > the
> > > cracks in it today. I was using a cheap 120A gasless MIG welder, but I
> > > would notice that eventually that the cracks came back in the same spot.
> > > What's surprising too, is the place where the metail cracked is actually
> > > pretty thick. The crack must be very deep for WD-40 to spray out. Also
> > when
> > > I let the metal cool after welding, I hear this clicking noise
> > from it. Am
> > > I welding this wrong, or are these manifolds really no hope? I see some
> > > repaired manifolds at Dad's and such..are these worth it, or will these
> > > crack soon too? Would a ceramic coating protect it from high heat and
> > > cracking again? Thanks.
> > >
> > > -ameer]
> > >
> >
> >
>
>