Reply to: RE>RE: RE: Paint
Time to add my two cents to the great paint debate:
I personally would not paint a car with lacquer; it's not as durable as
enamel. Painting a car is such a big job, that you want it to last as long as
possible. Lacquer's UV resistance is poor; it tends to dry out and crack in
the sun.
The problem with enamel, as TeriAnn rightly surmised, is the difficulty in
fixing mistakes. You *CAN* sand out, and yes, *polish* enamel, but you have to
wait until it "cures". For normal enamel, this takes about a month. Not much
fun when you have a run.
The modern alternative to hard-to-fix enamel is "Catalyzed Acrylic Enamel".
This is regular acrylic enamel with a "gloss catalyst" added. The gloss
catalyst has the following effects:
* It makes the paint glossier.
* It makes it cure in one or two days instead of a month
* It makes the paint highly chemical resistant
So with my catalyzed acrylic job, I paint on Saturday, and fix my runs on
Sunday. I have two choices in fixing those runs: either I sand them off, and
recoat the affected panel; or I sand them off and buff out the sanding marks.
The first choice is the easier one.
The hard part about shooting enamel is not so much avoiding runs, as
avoiding Orange Peel. This insidious effect makes the paint surface look
mottled instead of perfectly flat. It happens because the paint didn't "flow
out" properly. You can see the difficulty in avoiding orange peel in most new
cars. I think that 99 percent of all new cars have it. Fords have it. Chevys
have it. My new Nissan truck has it. New BMWs and Mercedes' have it.
To spray enamel without orange peel, you must:
* Hold the gun about two hand-spans away from the work.
* Run the air pressure fairly high, about 65 PSI
* Pile the paint on until it almost sags, but not quite.
( this is for the second coat. For the first coat, spray a light, dry
coat and don't worry about even, full, coverage. This first coat will tack
out, and make a nice sticky surface for the thick-glossy second coat to stick
to, helping you avoid runs and fish eyes. )
Shops like enamel, because you essentially spray the car twice, and ITS
DONE! You don't have to go round and round it, spraying coat after coat....
My time ( & TeriAnn's time ) is just as valuable as the shop's time, so I like
it too :-).
Since TeriAnn has a stripped car, she can start off by painting all the
insides and undersides, and make her beginner's mistakes there.
By the way, about tack rags: These are soaked in a sticky goo that
attracts dust. So far so good. Unfortunateliy, the sticky goo also likes to
stick to your work. And can ruin a paint job. So don't rub & scrub with that
tack rag! Just run it lightly... no, lighter than that, over the work, just
barely touching the work, no pressure at all.
SAND SCRATCHES:
Ugh. This is where you spray the car, it looks great. You get up the
next day, and it don't look so great no more. There are little lines under the
paint where you sanded. You can avoid sand scratches by:
* Make sure the primer is good and dry before you color coat. Maybe even
before you do the final sanding. The thing is, that in the case of lacquer
primer/surfacer, it can take a week or so for all the solvents to really
evaporate out of it. And as long as they are evaporating, the primer is
*shrinking*. The bottom of a scratch is thinner than the top, so they shrink
at different rates, and an invisible scratch enlarges into visibility. This is
especially bad when you have primer covering the sanding scratches in the
*metal*.
* Do a final sanding with 400 grit, or even 600 grit. Make it really
thorough, so you know that all the scratches remaining are fine-grit scratches.
One last thing: Whether TeriAnn sprays lacquer or enamel, she must get
her painting area clean! The last time I did a painting project in my dirty
garage, it took me two weeks to get it clean. First I used my blowgun to blow
the dust out of all the nooks and crannies. Then I vacuumed the floor. Then
the blowgun again. Then the vacuum. Then I vacuumed the nooks & crannies.
Then the floor... Then I mopped the floor twice. Then the blowgun....
- Jerry
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