Part cleaning for Alodining (Chromate Conversion)? 2

[keffassefa]

I have a cylinder barrel which is cast aluminum alloy A356.2-T6 which needs to be be Alodined as per MIL-C5541E, CLASS 1A.
Since the barrels are machined and water based coolant is used in the machining process, what type of cleaning need to be done before sending out for the Alodine preocess?
My concern is not to create any contamination on the cleaning bath and the part itself during the surface prepartion stage.
Any suggestion please?

 

[CorBlimeyLimey]

I am in the process of Alodining some parts as we "speak". I am not familiar with the MIL spec you mention. We use the Alodine partly for cosmetic & partly for UV non-reflectivity qualities.

We used to wash in Propanol, then Acetone prior to an Alumiprep etch. Now we just wash in hot water using Ivory dish washing detergent & a non-abrasive brush, prior to the Alumiprep. So far it works great. On the more visible parts I wipe with Acetone ... just to make sure, but all the non-visible parts have turned out great so far.

from (the City of) Barrie, Ontario.

I tried sniffing Coke once, but the ice cubes got stuck in my nose