On Tue, Feb 16, 2010 at 6:39 PM, David Beierl <dbeierl@attglobal.net> wrote:
> At 01:09 AM 2/16/2010, neil n wrote:
>>
>> I heated them up with a standard propane torch. I kept flame moving
>> and applied light pressure until crank started to bend. It didn't take
>> much heat to do this but the plastic cover may melt a bit. In my case
>
> Fascinating. �I thought these zinc alloys were hot-short so I specifically
> *didn't* heat it. �Maybe it's only the Zamak series or maybe I'm just
> completely wrong about it. �Can't test that part very well as all the Zamak
> parts I have belong to the lathe. �But I'll keep the torch handy for the odd
> zinc casting in general...
>
> By the way, when you're heating brass and other zinc alloys try not to
> breathe the fumes. �"Brass-smelters ail" isn't terrifically serious, but it
> isn't pleasant either. �I actually got a mild case from polishing a brass
> vase with a Dremel tool (wrong tool for the job anyway...).
>
> Yours,
> David
>

Thanks for the heads up.

yah I don't know why it worked. You obviously have way more knowledge
of metallurgy. I just took a gamble as I had spare cranks.

Have used the driver side crank w/o issue so far, so likely haven't
fatigued (or made more brittle?) the metal that much or at all.

One thing worth mentioning is that there was a noticeable sharp nub
that got exposed once plastic cover removed. Sharp enough to scrape
ones hand or at least annoy an unknowing user when rolling down the
window.

I was really careful with the flame. Didn't take much heat before it
bent quite easily.

-- 
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines