Is there a hi-temp expanding foam on the market?

the easiest and best way would be remove the head and then do the repair. So
much faster...


"Fred Mann" <famnn RemoveThis @bellsouth.net> wrote in message
news:v3QVj.1917$Kk3.169@bignews9.bellsouth.net...
>
> "jim" <"sjedgingN0sp"@m@mwt.net> wrote in message
> news:1210461952_1998@isp.n...
>>
>>
>> none2u wrote:
>> >
>> > "jim" <".sjedgingN0sp"@m@mwt.net> wrote in message
>> > news:1210378750_1932@isp.n...
>> > >
>> > >
>> > > Fred Mann wrote:
>> > >>
>> > >> Unfortunately, everything is so rusted that it would be a massive
>> > >> undertaking to do it right. Not worth it to me.
>> > >> I may try the red RTV though. Thanks!
>> > >
>> > >
>> > > Furnace cement ought to work. Get it from a place that sells wood
> stoves.
>> > > Follow
>> > > the instructions for filling cracks. Give it a full day to dry. You
> have
>> > > to make
>> > > sure you get all the moisture out before you get the temp above
> boiling or
>> > > it
>> > > will crack.
>> > >
>> > > -jim.
>> > >
>>
>> >It wont work either. Been there done that. It wont take the gas pressure
> or
>> >the heat.
>>
>> Yes I hesitated to offer the advice because it probably won't work if not
>> done correctly. Furnace cement will definitely take the heat - a lot more
>> heat than a car exhaust usually gets. And it expands at the same rate as
>> iron so heat and expansion aren't a problem even if you get the exhaust
>> cherry red.
>> It won't work on tin exhaust parts that flex but for filling a crack
>> where it is rigid and there is no flex it shouldn't be a problem. Of
>> course there is a bit of skill to applying it correctly so that it
>> adheres
>> and locks itself in. It won't work on furnaces and stoves either when not
>> applied correctly.
>>
>> -jim
>>
>>
>> >He has to live with it or replace the gasket or manifold.If its
>> >>warped too much.
>
> I think I'll try this next ... if there is a "next" . I JB welded it a few
> days ago ... maybe it will hold more than a few months. I don't drive that
> much.
> And by the way, the car is a 1983 VW Rabbit GTI. And the rust problem is
> limited to the nuts and bolts - the manifold seems to be fine. The nuts
> are
> starting to look like something off of an excavated sea wreck. I don't
> think
> I have the tools or patience to do it right.
> Thanks again for all of the help!!!
>
>

In rec.autos.makers.vw.watercooled Fred Mann <famnn RemoveThis @bellsouth.net> wrote:
> Hello,
> I have a small hole in the exhaust manifold right where it attaches to the
> engine -- actually a small piece of the gasket is missing. There's a little
> space in there that would seem ideally suited to accept a dollop of foam.
> The foaming insulation at the hardware store can only deal with temps below
> 200 degrees. Is there anything out there with a higher temp rating?
> (JB Weld works okay, but doesn't seem to last)
> Thanks!!!!

JBWeld will not handle the heat. Period. They explicitly say on the package
not for exhausts and that its only good to 500 degrees, and honestly, I
don't even believe that. The exhaust there is probably closer to 1000
degrees. There is a product called "Hi-Temp Lab-Metal" (www.alvinproducts.com)
which is supposed to be good to 1000 degrees. Honestly, even that may
not be enough. As with anything, it is strongly recommended the surface
is clean, dry, oil-free, and sanded so it is rough to promote adhesion.
They also claim you need to slowly heat it to 425F and then keep it there
in order to reach the claimed 1000 degrees. I think you might stand a
chance of doing that with a heat gun. I think using the engine to do
it would be unwise.

(Disclaimer: I am in no way associated with Alvin Products or any distributor
of it. I have never seen, much less used one of their products in person.
In short, I'm not endorsing its use, only pointing out its existence)