Painting and drilling boxes help!!!

[T-Man]

I'm making an OD pedal for my cousin for x-mas and my sister is going to paint the box (she is an excellent artist)

What kind of paint should be used for a base coat and for the actual art?  Also I'd like to put a clear protective coat to protect the artwork, what can i use?

Second, for drilling boxes is a hand drill ok?  Should I get a drill press? I plan on making PCBs eventually... is a drill press better for that?

Thanks
T-Man

[David Deen]

Hey T-Man,
I've used testors enamel in the spray can for plastic models, etc. The kind you can buy in hobby lobby. The best results I've got are when I do the following steps:

1) 1 or 2 coats of primer. just any kind of spray on primer is fine.
2) 2-3 coats of paint
3) bake paint at ~400-450 deg farenheit for ~40 minutes in an oven

I've clear-coated some of my boxes AFTER the bake and they turned out quite nice. If you put the clear coat on before, it turns a very ugly drab yellowish brown color and totally screws up the paint job. Baking the paint on has really proved to work well. I suppose it takes some of the liquid/water out of the paint so the paint becomes harder. Other paints may be better, I don't know.

As for the drill press, I would highly suggest it compared to a hand drill as you can be much more accurate at drilling smaller holes. Certainly true for PCB drilling. I would suppose though that you could manage with a hand drill when you're drilling boxes. Though I've never tried it I doubt it would cause too much trouble for that.

-David

P.S. hey post some pics of the paint job after it's done. If the artist is good it could look totally awesome.

[brad]

don't bake boxes in your kitchen though!

[T-Man]

I think I've got a line on a used toaster oven so that shouldn't be a problem!!!

What if i went primer->basecoat(color,baked)->art->clear topcoat

for everything but the art i would try automotive products....

could regular paint be used for the art? i.e. acrylic or whatever or would that mess up?

thanks guys!

[AL]

I've pretty much given up on painting boxes. I could never get very good results as far as getting the paint to stay. So, I've started using spray on truck bed liner. Someone here recommended it - can't remember who but thank you. I've had better luck with that. I use a fine tip paint pen for the lettering and spray a few coats of clear coat overtop of it. It's not as fancy but so far I've had better luck with it.

AL

[Lonzo]

AL

Care to post a pic or two of your work?  I like the bedliner look but have not seen any examples. 

thanks,
lonzo

[Fret Wire]

1) 1 or 2 coats of primer. just any kind of spray on primer is fine.
2) 2-3 coats of paint
3) bake paint at ~400-450 deg farenheit for ~40 minutes in an oven

You'll get much better results if you use a metal etching primer. The finished job will look the same no matter what primer you use, but without an etching primer, the paint will chip off down to bare metal fairly easy. The clear coat bonds to the base coat, which bonds to the primer. Without etching primer, there is no bonding of the paint to the metal of the enclosure, so chips will come off down to the metal completely.

You don't need anywhere near 400 degrees to bake a finish, 120-200 will work just fine.

You're right, baking the clearcoat isn't a good method, especially if decals are used.

[ronh95]

I just completed my first scratch build after a couple of BYOC kits.  I sanded the box with 220, cleaned with acetone, then used the self etching primer from Small Bear (an Eastwood automotive product) which worked great (high build, quick dry, etc.), then sanded very lightly with 320 and applied the Hammerite finish paint from Home Depot.  Worked out very nice.  Seems like a hard surfaced paint.

As for drilling, while a drill press is nice, in my opinion it's not necessary.  I bought a Unibit after hearing so many good things about them here, but will admit to being skeptical.  It was $18! I wasn't sure how it would work in a handheld drill motor either.  After using it however, I am a believer.  I predrilled each hole with a new 1/8" bit as a pilot, then enlarged them to the proper size with the Unibit.  I was amazed at what a clean job the Unibit did. Perfectly round holes with no burrs on my Hammond 1590B enclosure.  I'm used to the holes from 3/8" up turning out less than round with a conventional bit and these are perfect circles.  I used a DeWalt 14.4 cordless drill for all my drilling.  I did lightly center punch each hole with an old fashioned hit-it-with-a-hammer center punch to prevent wandering.

Good luck! Ron

[T113]

I got an el-cheepo drill press at harbor freight for around $40.  Does the trick!

[David Deen]

You'll get much better results if you use a metal etching primer. The finished job will look the same no matter what primer you use, but without an etching primer, the paint will chip off down to bare metal fairly easy.

AAHH, you're right! Yeah, actually I have had that problem. I try to take care of everything I build or own (despite the inherent stomping) so I don't have too much chipping but I have had some. I think next time I'll try the etching primer. Thanks for the heads up, Fret Wire.

Also you mentioned 400 deg was too high? I had read somewhere of someone doing that so that was the recipe I used. It always turned out nicely for me but I suppose 200 would keep down the paint smell a bit.

-David

[robbiemcm]

I think the idea of etching boxes was brilliant. I've never painted one and not sure if I will ever be bothered, but that etching is mighty tempting! Use the search function and type in "etching boxes" and it should come up, that's the exact title of the thread.