Paint a 3-channel copter

Paint a 3-channel copter Dec 5, 2010 15:36:13 GMT -5

Quote

Post by killbucket on Dec 5, 2010 15:36:13 GMT -5

Can't get this off of a shelf.

Let's see how I did this:
MOST important, is preparation for painting.

Make absolutely sure everything is clean.
Paint is a highly planned chemical compound- and anything contaminating the application process can lead to unpredictable results. Paint on top of a imperceptible oil or soap layer can look great at first, but peel or chip easily later.

Paradoxically, it's what you do AFTER spraying or otherwise "applying" paint, that has the most consequences: paint takes time to change from a liquid to a solid, and humans are impatient as a general rule.

"Just walk away."

That's probably the single most important thing to DO when painting!

After washing a part and drying as best you can, don't assume all moisture to be gone, and hurry on to the primer or paint can.
"Just walk away."
Give a little time to let any water residue evaporate, at least a half-hour. This is a good practice, because once you start spraying paint, you have to "Just walk away" and let it dry anyway.

More paint-jobs of any given item are screwed up at this point- people just have to "do" something in those critical moments.
"I'll just turn it around to get the other side..." Kee-rash!
"Just walk away..."

PAINT TYPES

I like enamels for the most part, because they naturally dry to a high gloss, and can be applied over just about anything without risking a paint reaction like lifting. Enamels dry thru a two step process. First, the volatiles (liquid part added to allow spraying) evaporate and the surface is produced. At this point, the coating feels and even seems dry, but will continue to 'cure' for several days or weeks, depending on formulation. This is a process called Decarboxylation . During this time, the enamel actually takes IN oxygen, completing the cure process. The paint coating is hardening up while this is happening, and special care must be taken to prevent scratching.
This is why you aren't supposed to rub, wash, or wax newly painted car for 30 days or so.

The typical "store brand" paint is enamel.

Lacquers are great if something's being painted for the first time, they are a bit more durable these days, and dry solely through evaporation. Depending upon application techniques, this can make for very fast work.

I found lacs to be much easier to use when doing custom work or airbrushing murals: Once they FEEL dry, they ARE dry, and can be safely masked over without worry. enamels tend to lift if masked too soon, so they take a bit more time and care to use in custom work involving more than one color application.

The typical auto touch-up paint is lacquer.

This is important to know:
Lacquers will attack existing enamel coats; the reverse is not true.

Lacquers shouldn't be immediately post-processed either, as it may take as much as a few days for a full coating thickness to lose its liquid components.
This process in both types may be directly observed as the "shrinking out"

PREPARATION

You quicken your work by following your washdown with a wipe with Isopropyl Alcohol (IPA), which will help the water transition off into the surrounding air a bit faster. If the item you're going to paint is relatively clean to begin with, I use IPA alone to prep the thing.

Gears were masked with a strip of paper and some tape.

The non-used hole on the other side was masked inside similarly, so the PCB wouldn't get paint on it too much.

Don't forget to mask the IR port window, or you'll be making a paperweight.

Another chunk of paper (Chinese restaurant menu-how fitting) it stuffed into the cockpit.

The charging socket and on-off switch were masked with tiny bits of tape.

The main shaft is masked at the top of the chassis, and the whole head encased in a baggie, and taped shut.
You don't want to paint the head,even if you've seen me do it: You will be re-tuning the flybar forever if you do.
DON'T PAINT THE HEADS.

So, our victim is ready for the spray job to come.
It has been shot with adhesion promoter spray, and will hold the new paint quite well.

Because we are using a light color (bright green) and the chopper is silver and black and tan, we need to have all this be the same color under that green. Otherwise, the parts will be different-looking shades when dry.
Additional coats of paint would remedy this, but remember, aircraft have weight issues. you want the overall coating to be as light as possible.

As stated in the first, a light mist coat of Red Oxide Primer is put on, and left to dry.

The other side. No more than this much paint in that first coat.
NOW-WALK AWAY, Human. Give it twenty minutes or so.
Go have coffee, pet the dog. Maintain a relationship.