[R-390] It followed me home

[Barry]

> The last process I would recommend for painting R-390 front panels or
> CY-979A/URR cabinets is powdercoating. There is plainly a place for this
> process in this world, such as painting automobile chassis and the like,
> but not when it comes to applying an extremely smooth, uniform, thin coat
> of paint to a panel like Collins, Motorola, EAC, etc., did many years ago.
> I have seen powdercoated R-390 front panels as well as CY-979A/URR
> cabinets, and in my opinion they look awful, not to mention the fact that I
> do not believe a color exists in powdercoat that very closely approaches
> that of the original R-390 paint color. Since many of the R-390/390A front
> panels were engraved, a very thin coat of paint is essential so the
> engraving can be properly filled. With powdercoat, it would be difficult to
> get the thiness of finish required to do this.
> Additionally, powdercoat may be difficult to remove once applied, if you
> should happen to make a mistake or be unhappy with the finish.
> 73,
> 
> Bruce, W2XR

I'll second that.  I had two engraved panels powder coated.  One came out fairly nice, but on the other one, the coating was too thick to allow the engravings to be filled in and still be crisp enough.

I asked them to remove it and apply as thin a coat as possible, but it still looked bad and I asked them to remove that and leave it bare.  These four processes (coatings/removals) left the pane in a pretty rough condition.  They have to bake the coating at somewhere around 400 deg. F but to remove it, they burn it off at around 600 deg. or more (not sure about those temps, but something like that).

I ended up having to fill in what was left of the engravings and other tiny pockmarks, sanding smooth, and priming/painting/silk-screening.  It was sad to lose the engraving but it was about the only recourse at that point.  I thought they could apply a very thin coating (and perhaps another shop could have done a better job), but that didn't work out that way.

You're also correct about the texture.  The panel with the powder coating had a very slight orange peel look to it.  It wasn't really al that noticeable and given that the finish was going to be extremely durable, I though it was a good trade-off.  Bottom line, though, I would not to go with the powder coating again.

Aso, I mentioned that I thought the Collins S-Line front panel paint was a pretty close match for the CY-979A/URR, but it isn't.  I got them both out in the sunlight yesterday afternoon and the panel is a shade darker than the cabinet.  I'm not sure if I'll paint the cabinet non-original to match the panel (kind of hate to do that), or try to get it matched.

Given our location (Huntsville, AL), there should be several places around here that can do military or aerospace finishing and would be familiar with the spec you have mentioned.  That would be ideal.

Thanks again for all the help advice.

Barry - N4BUQ