> -----Original Message-----
> From: Jack W Drews [SMTP:vinttr4@geneseo.net]
> Sent: Wednesday, January 06, 1999 6:29 PM
> To: shop-talk@Autox.Team.Net
> Subject: separating aluminum and steel parts
>
>
> I am working on the restoration of a 1930's vintage classic car. I am
> trying to remove the quite large aluminum heads, each secured to the
> block with 21 studs, 1/2" diameter. As you can imagine, electrolysis has
> had sixty years to do its thing with the studs and the aluminum head
> casting. The pistons are frozen in the bores so I can't use the rope
> tricks or compression tricks.
>
> After three days of attacking it with slender wedges of all
> descriptions, vibratory tools applied to the studs, and so-called
> "penetrating" oils which really don't, I humbly ask the list's
> collective wisdom: What are the current methods for separating
> aluminum/steel corroded joints?
> --
> uncle jack
> Happiness is a warm garage....
>
>
My response------------------------------------->
I have recently been through (and solved) a similar problem
with a 1931 Rolls-Royce Phantom II which uses an aluminum OHV head.
The technique that worked for me was to rotate each stud
clockwise and counter clockwise until the corrosion between the head and the
studs broke up. To rotate the studs I used Snap-On part CG500-2, a stud
removal collet holder, and a home-made collet. This tool has two significant
advantages over other types of stud removers for this application. First, it
is meant to be attached to the threaded part of the stud. Since only the
threaded part of the stud is exposed, this is no minor feature. Secondly,
this stud removal tool does not depend on wedging action to lock onto the
stud. This allows you to rotate the stud both clockwise and counterclockwise
to try and break up the corrosion. The reason for the home-made collet is
that these collets come in NC, NF, and metric sizes, but not in Whitworth.
If your car is not British, there is probably a suitable collet in the
Snap-on catalog. If your car is British or uses an unusual metric thread,
you will need access to a lathe and a tap of the appropriate size.
If you shear off or snap off one of the studs you are really
in trouble, so be careful!
Herb Tobin
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