Autobody Paint Tech 101:
First some clarifications: A "Paint Store" is not your local NAPA. Find a Paint store! NAPA is good for small quantities, but they do not mix paint. You will find your best selection at a Pro paint store.
There are many manufactures of paint.
I use PPG Starbase or DBC or DBU as a basecoat. Starbase is lacquer. DBC is better. DBU is best, adding a catalyst to the thinner (reducer) to make the base color chemically cure. Some painters like other brands. The important thing to remember is to use the same manufacturer throughout the process. If you use X brand primer, use X brand clearcoat. Keep it consistent. The chemical composition of it all is very important. I like PPG (the most expensive). This article will use PPG products, because I am familiar with them. One thing about painting a car, the bodywork labor is at least 50% of the price of the job. That leaves 50% for materials. Why scrimp on the materials? Use the best you can afford!
The paint store salesmen are your friends. They are highly trained on all the products they sell. They can teach you about paint. Ask for it! A motivated paint store salesman will teach you about his products. He sells more paint that way. I once had a Tech take me around back and teach me how to color sand and buff on a fresh black paint job on my 440Z Cabrio.. I have since bought $500 worth of sandpaper and buff compound/pads from that store….not including paint.
1. Bodywork. Walk around the car and look at it.
Park it in the sunlight and close your eyes. Feel along the car
and sense the difference in the surface temperature of the metal. The
bondo will be colder than the metal. Mark or remember the
cold and low spots. Your fingers and palm will be a better judge
of low spots than your eyes. The old magnet trick works to find
filler, if you remember that the magnetic properties of the substrate
are all relative to the bare metal. There is a calibrated magnetic
gauge available that tells you the thickness of the paint, available at
Feather edge it. Scratch up the metal good with 36-80 grit on your DA. You can do this with the DA or by hand. Apply the filler to an area at least 4x the size of the repair. Grab a 16" "longboard" sanding board armed with 80 grit and sand the area you filled. Get it reasonably smooth (feel it with your hands).
Sandpaper comes in two weights. One grade fills quickly, the other lasts a lot longer; but costs more. I use the better grade to save money in the long run….
You gotta have tools! You will need a compressor. I have
gotten by with a 3 hp 20 gallon for the past 10 years. A air
powered DA will make it run nonstop. You will also need a paint
gun. There is no reason to buy a traditional siphon feed (cup on
the bottom) gun. They are inefficient. The air pressure
needed to feed the paint is between 40-80 psi. At this rate, there
is a lot of overspray. These guns are virtually outlawed in
California, as they waste so much paint and blow it into our air.
There is a new Sheriff in town, and his name is HVLP (or High Volume/Low
Pressure). These guns have an increased "Transfer
Efficiency" and reduce overspray by 20-50%. This directly
impacts your pocketbook, as you buy less paint at the store. HVLP
guns need a lot of air volume, and my little 3 hp 20 gal does not keep
up with it. Another option is a gravity feed gun, either in a HVLP
or non-HVLP setup. The non-HVLP guns still have the high
efficiency , as they do not need any air pressure to get the paint out
of the gun. A gravity feed gun has the paint cup on top. It
flows out on its own. The air pressure is only there to atomize
it. These guns are very cheap at Harbor Freight (1800 423-2567
$40?). At this price, you can affords to throw away the gun after
every job, although mine are going on 2 yrs old and 20 cars. I
have found that my little compressor will keep up with a gravity feed or
a siphon feed gun because you are not spraying continuously.
Refilling the cup gives the compressor time to recharge, as does walking
around the car. There are also mini guns out that fit in a door
jamb, or can be used for those smaller jobs. I can't stress enough
the value of a gravity feed gun. It saves paint, reduces overspray,
and gives consistent show quality jobs. I even paint my house with
it. The cup on top design makes cleanup a breeze. It can go
in the dishwasher if you are using water-borne paints or housepaint.
Wax (not!). Flame on, Wax Salesmen! The paint mfgs say don't wax for 30 days. Don't ever ever use 5 Year Miracle Wax on a fresh job. Don't listen to me, ask the paint tech at your paint store.
Carwash -by hand. Make your shine last.
Color sanding and buffing. After the car comes out of the booth
and you find your trademark (mine is an eyelash in the top coat of clear
and usually a run near the door handle), let it sit for a few days.
Grab some 1000 grit on a 5" board and start wetsanding out the
runs. A slight blast of contrasting color of paint over the run
will act a as a guidecoat. It is very hard to see a run in the
clear when you sand it to a dull sheen. The guidecoat makes it
show up clearly. Anyway, sand out the runs, gradually working up
to 1500 grit abrasive. Then you need to buff the flat paint out
into a high gloss. I use a Milwaukee buffer and Presta compounds.
There are dozens of buffers and hundreds of compounds. Presta is
very cheap and works fantastic. Use what your mentor or paint
Painting the vinyl and plastic in a Z is easy. There are 2 sources for the dye. If you don't have a paint gun, find SEM vinyl dye at a good paint store. SEM is the only way to go, and I have never found another product that works as well or lasts so long. It also looks totally natural. They have Satin Black for your 240Z, and Napa Red for your red 240Z. They have ZX colors, too. Please do not even consider any other brand. Been there, done that. In my experience, there is no other brand that has the correct gloss, durability, and chemical composition to bond to the vinyl. SEM is about $7/can. I use 4-6 for an entire interior on a 240Z. If you have a paint gun (door jamb gun is good, HVLP jamb gun even
better). Dupont has vinyl dye that is comperable to SEM. It is about $20/quart. Does one car.
Preparation is everything! Here's my process:
Note: DO NOT PAINT THE SEATS. IT WILL RUBv OFF EVENTUALLY ON YOUR 501'S.
The Napa red is a precise match for the Datsun red interior. Even a patch of paint will blend in to the existing panel.
The theory behind the lacquer is that it chemically softens the VP. When you apply the dye, it soaks in and grabs the substrate.
Dupont also has texture paint to redue the texture for Ford Bronco
tops. It so happens to look like vinyl when it is dry. I use
it to redue the sill plates... It also works for roll bars to spiff them
up. The stuff is bulletproof when dry. It does not match the
Datsun sillplate vinyl exactally, but it is a lot easier than trying to
recover that rusty piece with contact cement and vinyl. This paint
has to be applied with a non-HVLP gun (your normal old fashioned gun is
not HVLP). It's the pressure that makes the spiderwebs as it comes
Bare metal prep 101:
The epoxies do a great job of sealing off all the substrates.
Modern paints are very hot and agressive. If applied over a old