49520

Precleaning of castings for coating  

July 29, 2008

Dear Sir,

I had been trying to do an organic coating on ferrous grey casting. As a standard procesdure, the casting was precleaned using Degreaseing solutions, followed by rinsinng in plain water, followed by organic acid derusting, then rinsing by water.

But I find the adhesion of the coating was poor.

Then I tried cleaning using Hcl acid (10% concentration). I observed black powdery layer formed on the casting surface. Naturally, the coating peel-off was observed. This I guess is graphite particles.

CAn you please suggest me an good casting cleaning process, suitable for coating.

Mahesh Behra
Pune, India

Mahesh Behra
Plating shop owner - Pune, MAharashtra, India