Frank, when I was in the Navy, then later in aircraft mechanic school
for heavy cleaning jobs we used a mixture of detergent soap and diesel
fuel in a pressure wash. The item was soaked in mineral spirits for a
couple of days, the pressure washed, pressure rinsed with clear water,
the force air dried. Then a light mist of minieral spirts sprayed on,
mineral spirits being an oil base as well as a solvent. This process
didn't really address corrosion issues with aluminum however. For
corrosion with aluminum it was a wire brush and zinc chromate for
corrosion control.

One problem with aluminum castings is that they can develop what is
known a "inter-granular corrosion" where the corrosion extends
completely through the metal from one side to the other in the form of
granules.. Eventually this will weaken the metal and cause a failure.
Not any real way to deal with that except replace the part.

Regards.

John Rodgers
88 GL Driver

Frank Condelli wrote:

>What's the trick to getting the engine case  sparkling clean when rebuilding
>?  I have looked into this locally and have  been told by two engine
>rebuilding machine shops that the chemical dunk tanks  they normally use are not good
>for aluminium.  The chemicals they use will  turn the aluminium to mush they
>say.  They also say there is no  aternative other than pressure washing or
>perhaps oven baking.  I have  tried various engine shampoos and pressure washing
>but the corrosion from oil  and salt deposits on the cases remain.  I think
>there must be a chemical  alternative.  Anyone with suggestions please ?
>Cheers,
>
>Frank  Condelli
>Almonte, Ontario, Canada
>_BusFusion_ (http://members.aol.com/BusFusion/bfhome.htm)  a VW Camper
>camping event, Almonte, ON, June 10 ~ 13, 2004
>'87 Westy & Lionel  Trains
>Member: _Vanagon List_ (http://www.vanagon.com/) , _LiMBO_
>(http://www.bcn.net/~limbo/) , _IWCCC_ (http://www.westfalia.qc.ca/)  & _CCVWC_
>(http://www.ccvwc.ca/)
>Vanagon/Vanagon Westfalia Service in  the Ottawa Valley
>_STEBRO/Vanagon Stainless Steel  Mufflers_
>(http://members.aol.com/Fkc43/stebro.htm)
>_Frank Condelli &  Associates_ (http://members.aol.com/Fkc43/busindex.html)
>or  http://frankcondelli.com
>
>
>