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Powder coat problems due to masking need

I have an extruded box with open ends, that is being powdercoated. In the past we would attach the front and rear panels to the open ends with two-three screws and attempt to self-mask the ends. This little box will need to contain GIG traffic from new boards going into it. The problem is the existing method allows for some overspray and it is very difficult for the assemblers to remove the powdercoated screws. I need total contact along the profile surfaces of the extrusion for the front and rear panels to make contact to contain the GIG noise. I have tried having the painter mask the entire profile surfaces, but this creates two problems: they don't really have a place to put the hanger for painting and baking and when they do there is a very sharp lip if powdercoat left along the outside edges of the profiles.

How can I have this part masked & painted without that problem occurring or is there other conductive paints that are inexpensive and will maintain a >.50 Ohms per Sq In on the market, so I don't have to mask at all?

Tracy Ramsdell
Telecom - Merrimack, NH, USA
2003

My solution would be to develop a rack that mounted on one of the holes on your product, fully masking that hole. On any other masked surfaces I would use a silicone "pull plug" and remove it between powder application and the cure oven. Removing the plug before cure will eliminate any "bridge" or adhesion to the plug that may contribute to flaws in the cured film.

Andy Peal
Automotive Components - Grand Rapids, Michigan, USA
2003

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