Corrosive Protection Paint on Galvanized Sheet

[AungKyawTun_HVAC]

Hi,
We are requested to paint (Primer 150 micron + Top coat 75 micron) on the pre-galvanized sheet metal(G60)0.85 mm.
Question is that which type of surface preparation shall be done prior painting since the sheet metal is only 0.85 mm.
Thanks

 

[pierreick]

Hi,
To me very weird question , Galvanized sheets are self protective against corrosion . This means that your client is going to loose the benefit of the galvanization (money thrown away) .
Remove the galvanization and apply the paint .

Pierre

 

[dik]

With galvanising steel, the coating has to be compatible with HDG. With some coatings, a zinc saponification occurs and the coating will not adhere for any length of time. I often spec safety yellow coating for HDG bollards or crane beams...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[AungKyawTun_HVAC]

Pierreick,
Thanks for your reply, we got shock for this request from client. They said, they prefer paint rater than pre-galvanized sheet metal.

@Dik,
If HDG, the surface may not be very smooth and there may be a way to paint. Now is pre-galvanized sheet for ventilation duct and we are having a challenge with that.

 

[dik]

It has nothing to do with the roughness... some coatings do not work well with HDG... make sure your top coat can be used with HDG.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik