If there is no load on the filler you could use Permatex copper, it works
well for high heat 700 degrees.
Not sure how hot a header right out of the head gets though it may vary
based upon load, etc.

http://www.holeshot.com/chemicals/permatex_prod.html

----- Original Message -----
From: "Mike Collum" <collum@VERIZON.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, February 01, 2006 8:02 PM
Subject: Re: JB Weld question

> It only withstands temperatures up to 500 degrees F (260 C).
>
> http://jbweld.net/products/jbweld.php
>
> Mike
>
>
> Stephen Overmyer wrote:
> > Apologies for the lack of direct VW content here but since JB Weld is
> > mentioned regularly here on the list I believe some of you users are the
> > best volk to ask...
> >
> > Q : Is JB Weld able to handle the temperatures of an exhaust manifold?
> >
> > JB Weld is not commonly available here in Oz but I have occasionally
> > seen it and will chase it up if it is likely to be able to do the job I
> > require.
> > BTW, this is not for any manifold on a Volkswagen but for my old Land
> > Rover where I would like to effect a short to medium term patch or
> > repair on a small crack in the manifold where it meets and bolts to the
> > flanged connection on the remainder of the exhaust system.
> > The crack is not large at approx 1.5" or 38mm long and could be
> > dremmelled out and filled if JB Weld was indeed a suitable product to
> > use. Just enough exhaust gas escapes at present to create some
> > backfiring on deceleration. Muffler putty would of course be useless...
> >
> > I do have a spare manifold but removal of the existing one is not an
> > option at this time as the vehicle is on a relatively remote property
> > and I have no intention of tackling the old manifold studs and bolts
> > while in this location. I always keep in mind the old maxim, "The
> > probability of an event occurring is in inverse ration to it's
> > desirability"...so in short, I aint risking it ;-)
> >
> > Just to add a little T3 content...I drove my waterboxer this week for
> > the first time in over 5 weeks as I have been away down at my property
> > in the Double Cab, leaving the WBX in the garage at home. She fired up
> > immediately with only the briefest of lifter clatter before settling
> > down to idle quietly....But what I really wanted to mention however was
> > how pleasant it was to get back in the van again. They really are a
> > pleasure to drive and some time away from the T3 really has made me
> > appreciate them all over again...especially with the new Wolf console
> > between the front seats that arrived from Terry K not long before
> > Xmas...:-)
> >
> >
> > Cheers,
> > Steve O
> > NSW Australia
> > '92 Transporter WBX Kombi
> > '00 Transporter Double Cab
> > '03 Transporter Double Cab (work truck)
> > '78 Land Rover 109 Series 3 Soft top ute (ex-Aust Army)
> >
> >