Not sure if it's been asked, but you've allowed penetrating fluid time
to do its' job?

Have you tried Liquid Wrench or other?

If you apply again, try scraping away corrosion on stud where it meets
the aluminum. Removing corrosion will help to allow more of
penetrating fluid to get down into threads. A triangle file with faces
ground to good sharp edge may be useful here. The tip (point) of file
can get into area where steel meets aluminum.

***Be careful.  Try not to scrape/damage the aluminum. It's easily
done with a tool like this and a deep scratch can result. ***

You can also use a small wire brush (with handle) or stiff tooth brush
to agitate fluid. Obviously the tooth brush won't damage the aluminum
so that may be a safer "bet".

Pretty sure aluminum expands/contracts faster than steel.

It's possible even a propane torch will get aluminum hot enough to
expand and help penetrating fluid get into threads below surface. Just
don't leave the flame in one spot. Keep it moving and don't put it on
the steel stud. If there's penetrating fluid already there, it may
ignite. Regardless, in theory, if the aluminum expands before the
steel, and you haven't heated the steel too much, it may help
penetrating fluid get into threads.

Neil.

--
Please send me your Vanagon/Westfalia links!
http://vanagonlinks.googlepages.com/home

Neil Nicholson. 1981 Air Cooled Westfalia.
http://web.mac.com/tubaneil

On 8/11/07, Tom Rowsell <tom@geoexploits.com> wrote:
> At this point, I'm about to give it over to some well-deserving mechanic
> before I bugger it totally.
> See http://exploits.dyndns.org/stud.jpg
> There's not much to grab onto, and I'm afraid to try and drill it.
> Specifically, what should be heated? My (lack of) logic tells me to heat the
> aluminum ???
> Thanks
> Tom
>
> On 8/10/07, dylan friedman <insyncro@yahoo.com> wrote:
> >
> > I have had amazing results with CRC Freeze It penetrating spray.
> > Mucho buckos, but has not failed me on rust bucket vans.
> > just follow the directions.
> >
> > df
> >
> > John <vanagonvw@GMAIL.COM> wrote: Geeez, not a good thing to read when I
> > am getting ready to remove my
> > exhaust system :-)
> >
> > Ben speaks of heating, and then dumping on the cold water. I am aware
> > that he knows what he is talking about  its just that I haven't done
> > very much with a torch on rusty bolts.
> >
> > I just got done torching the bolt on the spindle/knuckle while replacing
> > the struts on my son's car, and I  merely heated the spindle, and after
> > I got it all nice and hot, I had him twist the nut out, while keeping
> > the heat on the spindle, near the bolt.
> >
> > Did I do that completely wrong? Should I have torched it to the max, and
> > then tossed cold water on it? It sounds dangerous, or at least possibly
> > disasterous, but most of you will know more than me, so I figured I
> > better ask.
> >
> > When I am pulling the exhaust bolts  from the head, I should heat it up
> > good, and then hit it with cold water? Like from a bucket, or a maybe a
> > spray bottle? Do I want to directly heat the bolt, or focus on the head,
> > where the bolt attaches?
> >
> > Guess I better learn some more, before I go for it, as I would have
> > heated the head where the bolt attaches, and then twisted the bolt
> > loose, while it was still hot, and/or being heated by the torch.
> >
> > Happy to hear the right way, from those who do it often.
> >
> > Thanks a lot,
> >
> > John
> >
>