Double Zincating

+++++++

I am just a little bit dazzled about the fact of acid washing or removing the zinc seed deposited on the 1st zicating process, what is the reason or principle behind?

Anna Paat
NXP Semiconductors (Founded by Philips) - Cabuyao Laguna Philippines

+++++++

The reason is because it works better, Anna. The principle is less certain to me; I suppose that in the process of zincating, the aluminum surface grain or texture is beneficially affected in some way and when you strip it and start the zincating the second time the zincate sees this refreshed aluminum surface and reacts better with it.

In terms of material conservation it would seem to me that we should investigate as a reasearch project whether it is possible to gain the same structure that the first zincate gave using just an acid or alkali without actually having to wastefully apply and strip zinc metal.

Ted Mooney, P.E.
finishing.com
Brick, New Jersey