[DeTomaso] Campagnolo Paint preparation

[michael@michaelshortt.com]

Thanks for the reply, but according to what I found online, annealing
appears to make them even MORE brittle, that was
what I meant by educating me, it appears to me that the process would worsen
the condition, not improve it.

Thanks

Michael




On Tue, Mar 15, 2011 at 12:29 PM, Garth Rodericks <garth_rodericks at yahoo.com
> wrote:

>  <<< So please educate me, why woiuld annealing them be a good thing? >>>
>
> Because they crack!
>
> Magnesium castings, especially open-mold castings like our Campy wheels,
> tend to be porous, or at least have very large crystalline
>  areas. All wheels flex and bend slightly in use. Magnesium flexes too,
> but the flex-energy is not dissipated completely. Instead,
>  stresses build up inside the castings, eventually concentrating at an
> imperfection such as a casting pore or a crystal grain. Such an
>  area will eventually separate and connect with another pore or weak spot.
> A few more cycles of this and you have a crack growing in
>  the casting, with the accumulated stresses concentrating at the
> point-ends of the crack. This process works exactly like a micro
>  pry-bar!
>
> FWIW, when I stripped my wheels to refinish them I discovered one was
> cracked. Later tonight when I get home, I'll post a picture of an unusual
> and extremely dangerous crack that occurred on the inside rim hoop of a
> Campy that looked "perfectly good" from the front.
>
> Here's an article from Jack DeRyke on the annealing process for Campy
> wheels:
> http://www.realbig.com/detomaso/2000-06/1205.html
>
> Cheers!
> Garth
>
>


-- 







Michael L. Shortt
Savannah, Georgia
www.michaelshortt.com
michael at michaelshortt.com
912-232-9390


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