powdercoating

[skippy]

I'm looking for some advice re powder coating techniques. I get some products manufactured in 2mm sheet metal. The average panel is about 750 x 1300mm with 30mm returns and some with double returns of 30/20mm.

Firstly, my competitor uses pre-galvanised sheeting, everything is riveted together using huge external (i.e. seen) aluminium rivets with 10mm heads so therefore there are no welds whatsoever. (= cheaper manufacturing cost and customers like the idea of rust free, long life) Being galvanised, they only have to be painted on the outside (= less cost) and I have a feeling that he uses a spray on 2 pack epoxy paint or maybe polyeurethane instead of powder coating.

My products involve quite a lot of welding on normal steel sheet and then afterwards I send them for powder coating. I specified that prior to the application of the orange powder coating process, that they use a primer called "polyzinc" or "polizinc" which is a primer applied by the same powder coating process. The powder coating guy however, claims that a primer isn't necessary. My products are out in the weather all year long and must withstand the often harsh Spanish weather.

My questions are: Is powder coating the way to go or would I be better to look at some kind of 2 pack paint instead? Does powder coating need a primer on normal steel sheet for outdoor applications or is the colour coat sufficient? What kind of surface preparations are necessary for powder coating with and without a primer? The reason I brought up the info about my competitor is that maybe I should be looking at doing the same thing, minimal or no welds and pre-galvanised sheet?
What's your thoughts and thanks in advance.

[skippy]

just unashamedly giving this thread a bump. MC where are you?

[SKennedy]

bumpo