2 piece EM welding, skimming, and coating

[Stetina]

Yes,
I agree that pre heating and proper cool down probably increase one's
chances of sucess 95 %.
As far as Phil's comments about a failing engine mount problem affecting the
manifold ; after analyzing exactly where my manifold was cracked (and
Gerald's too),  I think we can safely say that it cracked in the hightest
heated area which sees the most flow.  This is the bottom / outside radius
of the collector (which carries gases from several cyliders) and is directly
in front of the turbo.  I don't see this area as impacted by a twisting
engine or exhaust system,  just the most concentrated area of exhaust flow
and therefore heat...
Joel
----- Original Message -----
From: Jörgen Karlsson <jurg at pp.sbbs.se>
To: <quk at isham-research.freeserve.co.uk>; <stetina at easy-pages.com>;
<quattro at audifans.com>
Sent: Monday, August 21, 2000 4:38 PM
Subject: RE: 2 piece EM welding, skimming, and coating


> Phil wrote:
>
> > In my experience, welding is very rarely successful.
>
>
> I don't think that the proper welding procedure are used very often, it is
a
> PITA to weld cast items.
>
> First the part should be normalized, this is never done!
>
> Secondly the part should be _very_ hot while it is welded, one way is to
use
> two welding torches to keep it (red)hot, while you weld it with an
electric
> welder with suitable electrodes. Of course powder welding the part while
it
> is hot is the best alternative, but it is hard to get someone that has the
> equipment for powder welding.
>
> Now the part should be normalized again... Most likely it is now badly
> warped and needs to be milled...
>
> If this is done the manifold will probably be as good as new, or a lot
> better!
>
> Anyone that has seen a welded part being normalized understands why welded
> manifolds tend to crack...
>
>
> Jörgen Karlsson
> Gothenburg, Sweden
>
> For sale:
> New K24-7000 turbo(S4), MC exhaust manifold, wastegate, downpipe.
> Used K26 turbo, MC exhaust manifold, wastegate, downpipe.
>