On Mar 14, 8:31 pm, Roy Lewallen wrote:


Calcium carbonate (Na2CO3), aka "washing soda", is sold at paint stores
as "TSP substitute". It's not as alkaline as lye (pH over 13), but with
a pH of 11.5 for a few percent solution it's still pretty darn alkaline.
Would it work in place of lye?

Don't see why not. Might just have to soak it longer. Fresh lye
works pretty fast and as it becomes depleted it takes longer, so this
would be about the same situation.

I'm not a chemist and don't profess any special knowledge of this
process other than what Iearned eons ago in the "chem lab" in our
engineering lab. We used to do our own aluminum passivation
(Alodine), silver and gold plating and so forth. For example, here's
one of the two-meter amps I've built:

http://k6mhe.com/n7ws/K7CVT_Amp_6.jpg

(Sorry about the quality of the image, this is scanned from an old
snapshot I took just before I polished it up and sold it.)

Before that I worked in my dad's automotive machine shop, where we had
a caustic hot tank for degreasing parts. You learned real fast to not
leave any VW parts in there overnight because the next day, you didn't
have any.