On Mon, 17 Jan 2011 17:47:17 +0000,
(DA) wrote:

responding to
http://www.rittercnc.com/metalworkin...ts-487279-.htm
DA wrote:
Don Foreman wrote:

A phosphoric acid wash never hurts either - like Aluma-Prep-33 (or
simple water softener resin cleaner - virtually the same stuff)
(Phosphoric acid and ethyl polyol)

This stuff makes a huge difference with aluminum. It completely
degreases, and leaves a surface that really holds paint. It makes any
paint wet better and flow out nice and level. Aluma-Prep 33 is made
by PPG or Ditzler and is found at places that sell paint and supplies
for auto body work.

Thank you for the reference. Yes, I would much prefer something that works
yet makes no fumes (or less than paint thinners, anyway).

However, I was looking for sources for the cleaner and found this page at
Henkel http://bit.ly/dFiEMk that describes a product called Turco
ALUMIPREP 33 'Cleaner and Conditioner for Aluminum' - judging by
similarities in the name and that they do mention phosphoric acid, I think
it's the same product.
It looks like they do NOT recommend it for castings:

"Turco Alumiprep 33 should not be used on high copper bearing aluminum
alloys or aluminum castings."


"Not on high copper bearing ----- castings"
Not on castings? Can someone who worked with phosphoric acid cleaner
comment on that please?
Aluma-prep and alodine are both used on many aluminum castings (like
aircraft engine crank-cases)

Or, and I do get Rich's comment about this not having to be
hospital-clean. Indeed it probably shouldn't be. But to paint these parts
properly is just a part of the fun for me - it is, after all, a hobby
project. That's why I keep bugging people with questions
The ResCare product is roughly 10% of the cost of the Aluma-Prep and
has virtually the same composition. Readily available at plumbing
supply and home supply stores everywhere.