52015

Best Sealing for anodized aluminum diecastings  

April 28, 2009

Dear Sir / Madam,

We are aluminum alloy Die casters. We are doing Anodizing on our aluminum alloy castings.

During Anodizing – Sealing Process to be followed.

As per our knowledge, there are two types of sealing.

1) Cold Sealing (In cold water with Sodium Dichromate Sealing at Room temp.)

2) Hot Sealing (In Hot water with Sodium Dichromate Sealing at 90- 95 deg. Celsius temp.)

Kindly suggest and guide us, which is the better process.

Kindly confirm.

M. M. UMADI
- NASHIK, India

The cold process does not "seal" the pores, but fills them partially up with dichromate. Most anodizers that work to specifications will chose a proprietary like nickel acetate at near boiling.

James Watts
- FL