To paint or not to paint ?

[g4wim_tim]

For those of you following my home brew build for 160, 80 and 60 mtrs - it's finished all but for the case painting to match the front panel.

Question is do I really want to powder coat the case black to match the front panel or should I just leave it bare aluminium showing a few scribe marks and scratches ?

Powder coating would cover up the blemishes, but would also make the ventilation holes less effective likely reducing the hole diameter from 3mm down to about 2.5mm

Plus powder coating would make it look like just one big black box.

I'm open to being convinced either way - currently I'm leaning toward leaving the case 'naked'.

Regards Tim

[g4aaw pete]

Naked works for me, Tim

But, what a terrific looking pice of equipment!

[HamishBoxer]

Looks superb as it is now.

[G4YVM David]

Sorry...i say powder coat. It eithrr looks unfinished or something from a very expensive 'avante gard' dealership. To me it's unfinished. But it IS a remarkable job!

[David G4EBT]

Like you Tim, I've been a keen home-brewer since the mid 1950s, and I've never tried to emulate commercially made equipment, because we don't have the resources to do that, and we'll always fall short. The benchmark I've always used is to try to attain the highest homebrew standards within the limit of my skills and resources, and to never make anything that I'd be embarrassed to take the cover off.

Using that benchmark, what you've designed and built is superb - the 'real deal'. Perverse as it may sound, I think if you were to powder coat it, would actually detract rather than enhance the appearance. It would look more 'Panda Cub' and less 'G4WIM', if that makes any sense.

Wonderful to know that while home-brew amateur radio is in inexorable decline, it's not yet extinct!

[G6Tanuki]

If you do paint/powder it remember to put some masking-tape along the faces where the grilles attach to the plates, and along the faces of the plates where they're screwed to each-other. You wouldn't want to go and destroy all that nice screening by an insulating layer between the parts.

Personally I'd go for black wrinkle-finish as found on 1940s HROs etc.

[Sean Williams]

How about powder coat the frame, and get the mesh anodised - would look very smart, and not reduce the diameter of the holes by a measureable amount?

[Radio Wrangler]

Why assume black for powdercoating?

A grey would look rather professional

David

[yesnaby]

I like it the way it is. But down the line the aluminium might not look so good after a few years. Difficult one!

[Radio Wrangler]

There is, of course, the problem of getting paint to stay on aluminium. It needs either etch-primers or else Alochrome treatment.

David

[Ted Kendall]

Don't mess with it - it's fine as it stands, and well fit for purpose.

[Sparky67]

It's obviously very subjective, but personally I think I would go for a light grey or silver (satin?) finish Tim. That would make it look 'finished' and cover any marks, and provide a contrast with the excellent front panel.

Martin
G4NCE

[RobinBirch]

Ooooh that's well done. How about seeing if you can get the aluminium anodised. Then you can pick a nice colour including a bare one so it would look similar to how it does.

Failing that - etch prime and then spray. All available from Halfords and it wouldn't close the holes. Always quite liked a colour with bare metal fasteners.

Robin
G5HI

[GW3OQK Andrew]

Excellent job Tim.

Just taking the smooth finish off the aluminium in a caustic soda solution is good. It leaves it matt finish. (I wonder if someone will bother pointing out the hazards.)
73, Andrew

[Bazz4CQJ]

One question that's hard to answer is that of how that surface will age; will it stay much the same or could it start to look less appealing?

I'm not a fan of powder coating. As, suggested, anodising could be good. As for paints, I had some really good results on aluminium using an etch primer from a company called Clostermann and would certainly use them again.

I think that one big advantage of painting is that if you don't like what you end up with, or it gets damaged, then it is easy to re-work. That is less true of powder coating or anodising.

Nice job!

B

[Andrew Mawson]

Give the aluminium a good clean up and then get it anodised. It will then remain tarnish free and be significantly less liable to scratching.

Personally I'd clear anodise it, but there is a whole of colours to choose if you wish.

[G4XWDJim]

I’d go with post 14 and then clear lacquer.

Jim

[g4wim_tim]

Hi guys,

certainly given me some ideas and questions.
I think powder coating the frame and anodising the mesh as Sean suggests in post #7 is a good option.

However not sure about how or where to get the mesh anodised. I guess I could leave it naked and let it naturally anodise.

But if I were to anodise the mesh then there'd be issues with its connectivity / screening.
Maybe clear lacquer on the mesh would be a better idea ?

Regards Tim

[Argus25]

There is another way and you can do it yourself without having to turn it over to the powder coaters and get a coat that is too thick.

Recently I had a large aluminium chassis to paint. (see page about 32 of this article: http://worldphaco.com/uploads/ARGUS.pdf ).

The trick is to ensure two things, that the aluminium is treated with Alodine or similar (used in the aviation industry to prime aluminium, it leaves it with a matt yellow finish) and that you use a high temperature enamel paint that you can bake in your own home oven, I used VHT machinery grey spray paint.

The result is great, exactly like a commercial finish and scratch resistant with good adhesion thanks to the primer.

Anodizing can look fantastic when new, but when scratched it is a cosmetic nightmare and does not lend itself well to touch up repairs, unlike paint.

PS: very cool transmitter.

[G4YVM David]

Originally Posted by g4wim_tim

Hi guys,

But if I were to anodise the mesh then there'd be issues with its connectivity / screening.
Maybe clear lacquer on the mesh would be a better idea ?

Regards Tim

Why? Anodised metal still conducts. It does on my landrover anyway. You can also get coloured anodising. They are dull colours, but still.colours.