| 1. |
Q.
What are the basic paint systems out there, and what is meant by a
"system"?
A. It's a company's paint line based on a certain
type of paint. Basic types of paint include Lacquer, Enamels and Polyurethane.
So, for example, DuPont's polyurethane line of paints are called "Chroma"
system. Their basecoat paints are called "ChromaBase", Clears
are "ChromaClear", etc. Their single-stage urethane paint
is called "ChromaOne". Reading their literature, they have
a specific protocol one should follow to achieve best results. The
various products are designed to be compatible with one another and
the reducers won't react negatively with one another when used as
intended. But that might not be the case with other companies products.
Spraying one company's base color over another company's sealer for
example and third company's clearcoat on the base color is just asking
for trouble. Compatiblity issues regarding their reducers and resins
could occur resulting in a paint disaster. For that reason, it's a
very good idea to stick with products from a single company. |
| 2. |
Q.
What are the differences between Lacquer, Enamel and Urethane paints?
A. The basic components
that make up each type of paint is different and they're not all compatable
with each other. Enamels, for example, contain different resins than
lacquer paints. You can't use enamel reducers to reduce (or thin out)
lacquer paint, they won't mix. And you wouldn't use enamel reducers
or any enamel hardeners for urethane paints. Lacquer paints are the
oldest, then came Enamels in the 60's and 70's, and finally Polyurethanes,
(or just "urethanes") in the 90's. Each system is based
on certain base resins and represents an advancment in paint technology
over the previous type of paint. Urethanes are the most recent edition
to the paint line and considered a better quality product than previous
paints. They're more durable and longer lasting while at the same
time very easy to apply. |
| 3. |
Q. Can I just paint
my car with spray can paint?
A. Yes, you can -- but it'll look like crap. Small
repairs in inconspicuous places like down low can be done with a
spray can and won't be highly detectable. But for high-quality,
long-lasting repairs, use automotive grade paints.
|
| 4. |
Q.
I know a guy that sprayed his whole car with spray can paint and it
looks pretty good. How did he do it?
A. Maybe he just finished it and it looked ok while
still 'wet'. But those paints don't have sufficient UV protecting
compounds (if any) and it'll fade quickly, you just watch. Plus, it
won't have any resistance to rock chips. In addition, what looks good
to one person, particularly a beginner, might look like crap to another.
We'd all like to be able to get nice quality paint jobs from $25 in
spray cans but the ugly truth is you can't. There's a system to follow
to get a quality paint job and using the right paint is of paramount
importance. |
| 5. |
Q.
I used spray can primer, can I cover it with automotive paint?
A. If it has been allowed plenty of time to dry
you'll probably be ok, but there's no guarantee. There's a chance
that the new paint's solvents might lift the edges of the primer.
If it's been on your car for a week and you carefully use a automotive-grade
primer or sealer before painting, you'll probably be ok. Lightly dust
some sealer on the primer edge first and give 10 minutes to dry. Just
lightly mist it on the spray can primer. Then apply the sealer like
you normally would. It'll be less likely to lift. |
| 6. |
Q.
Where do I buy automotive-grade paint?
A. There are automotive paint and body shop supply
stores that sell it. Check your phone book or maybe ask some local
bodyshop owners who the local bodyshop supply stores are. Also, it's
available at many auto parts stores. You probably won't find it sitting
on their showroom shelves, so ask the parts manager. If they sell
it, you'll have to give them your vehicle's paint code (usually located
on the driver's door) and they will have to mix it for you. Their
mixing station contains a number of primary paint base colors from
which they can mix about any color you need. |
| 7. |
Q.
How much does it cost to paint a car?
A. Well, it depends on the size of car, if it needs
priming and the type of paint you plan to use. But normally for a
mid-sized passenger car, figuring sealer, masking tape, sand paper
and sealer and paint it can run from as little as $200 for a true
economy job using cheap paint, to $500 for extra primer and basecoat/clearcoat.
If you plan to prime the whole vehicle and then seal and paint it
with basecoat clearcoat, figure on $450 or so for all the supplies.
You'll have reducers and hardeners left over for future job, though.
|
| 8. |
Q.
Why are automotive paints and primers so expensive?
A. Good question. I don't have a good answer for
that. It's hard to imagine why some quarts of mass-produced paints
can run $100! There are universal primers and clears on the market
that are pretty good and cost significantly less than those sold by
major manufacturers. |
| 9. |
Q.
I want to do a cheap paint job, what should I use?
A. Nobody wants to spend a lot of money on a paint
job so I tell this to everybody: Before you figure out what you want
to spend, consider your vehicle and try to envision the quality of
paint job you want to end up with. Spending more for higher quality
paint will give you a nicer looking and more durable shine (provided
it was applied correctly). Acrylic enamels are usually cheapest and
will have a shine that lasts about 4-5 years (if a urethane hardener
is used). They go on fast and look pretty good. If you're a beginner,
the only problem with them is that once you spray it, you really can't
fix runs or sags or dust, w/o taking away from the shine. A urethane
paint will last longer. One inexpensive urethane paint is Martin Seniour's
MSU paint line sold at most Napa stores. It's a watered-down urethane
paint that is surprisingly good for it's cost. It's not much more
expensive than an acrylic enamel. Most paint companies sell an economy
line of urethane paints. I think the best bang for the buck is to
spray a basecoat/clearcoat paint job using an inexpensive universal
clear. That would give you repairability (if you get runs or dust
during painting) and a shine that should last 8 or more years. |
| 10. |
Q.
What is basecoat clearcoat paint? Why is it good?
A. It's a paint job where a base color is first
sprayed down then a clear is sprayed on top of the base color. Urethane
basecoat/clearcoat paint jobs can last 10 years or longer. Other reasons
why it's a good paint system is it is, for a beginner, mistakes can
be more easily fixed. It's more durable, better for making paint blends
for later repairs and can be buffed to original luster even after
many years. |
| 11. |
Q.
What are urethane paints?
A. Paints based on urethane resins. A typical urethane
paint system includes urethane undercoats (primers & sealers)
and top coats (paints), and activators all based on compatible urethane
resins. |
| 12. |
Q.
What is the difference between basecoat/clearcoat paint and single-stage?
A. A single stage paint is applied in one stage
- the painting stage. The paint is shiny when it dries. After painting,
there's nothing else to apply. A basecoat/clearcoat system is considered
a two-stage paint system because it requires two application stages:
first the color paint (basecoat) must be sprayed on, then the clearcoat
must be applied. The basecoat or color coat alone does not shine or
have much durability. Indeed, you could easily scratch it up with
your fingernail. The clearcoat is what gives the paint it's shine
and durability. It's takes longer to spray a basecoat/clearcoat paint
job -- you might have two or three coats of the base color and three
coats of clear. That's 6 coats to apply. With a single-stage paint
job you can put on three coats of paint and be done with it. |
| 13. |
Q.
What are the advantages of spraying basecoat/clearcoat on my vehicle?
A. Longer lasting, increased shine, greater durability,
increased reparability. Also, dust, runs and other mistakes can be
buffed out without reducing the pant's durability. |
| 14. |
Q.
What are the advantages of single-stage paints?
A. Less expensive, faster to apply. For solid dark
colors like blacks and dark blues, when painted with a clearcoat,
scratches appear whitish (because they're really in the clearcoat).
Scratches in a single-stage dark color won't show up as well. |
| 15. |
Q.
Is basecoat/clearcoat paint better than single-stage paints?
A. It depends on what the application is. Generally
they will last longer and are more durable. Plus they can be buffed
out periodically w/o removing the paint's UV layer like would happen
with buffing a single stage. For newer vehicles and restorations it's
the paint of choice. Personally, considering that they don't cost
that much more than single-stage urethane paints, it's the only way
to go. However, that's not to say that single stage urethanes don't
last a long time either, they do. |
| 16. |
Q.
Will b/c last longer than other paints?
A. Almost for sure, provided you're talking about
a good quality urethane b/c system that was properly applied. |
| 17. |
Q.
What about regular acrylic enamel paint?
A. It can be good for low-cost paint jobs. Be sure
to use a wet-look hardener with it - it'll almost double it's life.
You can get a universal hardener at a paint and body supply store.
But before buying the acrylic enamel, price out low-cost urethane
paints like the MSU line available at most Napa stores or consider
spraying a base/clear job using an inexpensive universal clear. It's
not that much more expensive and lasts longer. Plus, you can fix goof-ups. |
| 18. |
Q.
Can I use an enamel paint from a home center?
A. Don't do it, unless you're looking for a paint
that quickly becomes dull and has poor resistance to rock chips. If
you're looking for a halfway decent paint job, at the very least buy
inexpensive automotive enamel paints from an auto parts store. It
will be better quality than home center enamel for about the same
price or a little more. Automotive grade paint has more UV inhibitors
than regular equipment enamel, so it lasts longer. Why put all that
work into getting a vehicle ready to paint and then try saving a few
bucks by using cheap quality paint? The best low cost job would be
using low-cost automotive enamel and a wet-look hardener. The $30
hardener might be the difference between a 2 year shine and a 4- 5
year shine. |
| 19. |
Q.
My dad keeps talking about lacquer paint. What's the deal with it?
A. Lacquer paints were used extensively throughout
the the 60's and 70's and even into the 80's. But paint technology
has improved. Modern shops use urethane paints almost exclusively.
They just last longer. One of the major drawbacks of Lacquer paint
is it becomes so hard and brittle that it chips easily. Lacquer paints
also give off a good deal of solvents which damage the environment.
They're illegal for use in many regions. |
| 20. |
Q.
I'm just starting out, are any paints particularly good for beginners?
A. Acrylic enamels are relatively easy to spray
and don't cost much. But my advice is to begin learning to use modern
paints like single-stage urethanes and base/clear. |
| 21. |
Q.
What are hardeners and activators and reducers used for in paint?
A. Reducers thin the paint out so the it flows through
a spray gun and allows the paint to properly flow out after it's reached
the paint surface. The reducers eventually evaporate. The hardeners
engage in a chemical reaction that produces cross-linking and makes
the paint harden up. |
| 22. |
Q.
Do I really need all the expensive reducers and activators (hardeners)
for the paint? Are there any shortcuts?
A. Yes. Modern paints require them. Trying to take
shortcuts to save a few bucks nearly always results in lousy paint
jobs. Stick with the type of reducers and hardeners that the paint
calls for. A couple exceptions exist. universal enamel urethane hardeners
are considerably cheaper and seem to work well. Also universal clears
which cost less can be used. But not all clears are created equal.
If you're doing a quickie repair on a bumper a universal clear might
be the way to go. But if you're painting a 72 Chevelle that you spent
two years restoring, stick with one company's paint system and their
best quality high-solids clearcoat. |
| 23. |
Q.
Can I mix some hardener produced by one company with another company's
paints?
A. It may work but for quality jobs it's not a good
idea. If it's a universal product, you can assume they've tested it
with most brands of paint. Sometimes they'll even say on the label
which products not to use it for. Use this rule of thumb: if it really
matters and you absolutely don't want to do the job over, stick with
one company's products throughout. |
| 24. |
Q.
What is the difference between slow and fast reducers?
A. Slow reducers evaporate more slowly which makes
them ideal for use on hot days. Otherwise, a standard reducer would
evaporate quickly and reduce the paint's gloss. A fast reducer evaporates
quickly and should be used in cold temps. It'll prevent the paint
from running. Learning to use fast, medium and slow temp reducers
helps create a paint that flows out well in various temperatures. |
| 25. |
Q.
What is a "wet-look" hardener, and should I use it?
A. It's a urethane hardener that can be added to
enamel paints. Enamel paint will harden w/o out it but with it it
really gets glossy. Most shops that spray acrylic enamel paint use
it. It reduces dry time, dramatically improves gloss, durability and
longevity. Like the name says, it gives it the "wet look".
Personally, I wouldn't even spray a set of old truck rims w/o using
it. |
| 26. |
Q.
What is Wax & Grease Remover? Do I need to buy some?
A. Yes, it'll help reduce paint disasters. Wax &
Grease Remover is a cleaning agent that removes surface contaminates
like oils and silicates which can lead to paint problems. It floats
contaminants to the paint's surface where they can be wiped away with
a clean cloth. Body technicians will typically wipe down a whole car
with it before performing any repairs, and again before beginning
the paint stage. Undetectable oils from the engine or road as well
as interior and exterior cleaners which might have gotten on the paint
can lead to disastrous paint problems. Sanding may just spread the
contaminants. To avoid having to redo a paint job, wipe the repair
area or entire vehicle down with wax and grease remover before beginning
any repair work. Wipe the area to be painted once again before applying
any sealer or paint. |
| 27. |
Q.
Who makes the best paint? How do I know which one I should use?
A. That's a debatable question, like asking who
is the best-looking woman/man. All the major paint companies produce
good quality products. Each company has premium as well as economy
paints. Many painters I have talked to feel Sikkens or PPG have a
slight edge over the competition but a lot of it depends on how well
one knows a certain paint line. For practical applications, they all
have great products that work well. When choosing a paint system,
many painters will tell you that availability is very important. Find
a nearby supplier that has convenient hours for you and is willing
to help you out and answer your questions. Also, once you decide,
stick to one company's products. Paint products are expensive so it's
cheaper in the long run so you don't end up with partial cans of reducers
and hardeners from multiple companies laying around (intermixing is
not recommended). The second benefit of using one company's products
is you get to know their products well and learn to spray them better. |
| 28. |
Q. Can you list some
links to company's websites?
|
| 29. |
Q.
What are "universal" clearcoats? Are they any good?
A. They're clears that are made by a third-party
company that can be sprayed over other company's basecoats. They're
usually quite a bit less expensive than clears produced by the major
paint companies, sometimes less than half of the cost. They have become
quite popular in the last couple years because paints have become
very expensive. They range in quality depending on the company but
many shops use them for daily repairs and use the clears (by major
mfgrs) for better quality paint work. Many companies producing universal
clears are themselves well known companies that make quality fillers,
primers and other automotive repair products. Evercoat and USC are
two well known companies that produce autobody products that also
make universal clears. Although most universal clears can be sprayed
over most basecoats, be sure to read the can or data sheets to ensure
compatibility with your basecoats. |
| 30. |
Q. So, what order
that I should apply all these products in?
A. Most shops do it one of a few different ways
depending on the situation:
| |
Bare metal, no bodywork
needed:
|
|
Bare metal, bodywork needed
|
| |
- Bare Metal |
|
- Bare metal |
| |
- Self etching
primer |
|
- Apply filler
& do bodywork |
| |
- Epoxy Primer |
|
- Self etching
primer over bare metal |
| |
- Sealer
(optional) |
|
- High-build
primer (sand if needed) |
| |
- Paint (or
basecoat + clear) |
|
- Sealer
(1 med-wet coat) |
| |
|
|
- Paint (or
basecoat + clearcoat) |
|
| |
Painting over
existing finish , No bodywork needed |
|
Painting over
existing finish - Some bodywork needed |
| |
- Clean w/Wax
& Grease Remover |
|
- Clean w/Wax
& Grease Remover |
| |
- Sand vehicle
with w/360 grit |
|
- Grind repair
areas to bare metal |
| |
- Sealer
(1 medium-wet coat) |
|
- Apply body
filler (sand as necessary) |
| |
- Paint (or
basecoat + clearcoat) |
|
- High-build
primer over bodywork |
| |
|
|
- Spray guidecoat
over primer |
| |
|
|
- Sand primer
as necessary |
| |
|
|
- Sand vehicle
with minimum 320 grit |
| |
|
|
- Sealer
(1 med-wet coat) over entire vehicle |
| |
|
|
- Paint (or
basecoat + clearcoat) |
**Many autobody repair technicians skip the self-etching primer stage
and apply primer directly over bare metal. But for best rust prevention,
you can't beat an etching primer. |
| 31. |
Q.
What are some good spray guns to use?
A. If you're just starting out, a cheapie HVLP import
spray gun from somewhere like Harbor
Freight will work fine. I've seen some very good spray jobs come
from some of these guns and have tried one out myself. Moving up in
price and quality , Sharpe makes a good spray gun as do Binks and
DeVilbiss. A good economy spray gun is the DeVilbiss Finishline series
(app $150 for HVLP). Sata is generally known to produce some of the
best gravity feed HVLP spray guns on the market. You need a decent
quality modern spray gun to properly atomize urethane clears if you
want the clear to flow out properly. When buying a spray gun, be sure
your air compressor can handle the requirements. |
| 32. |
Q.
Are paint fumes really that dangerous and how can I protect myself?
A. Yes. Read the safety data sheets for the paint
products you are using and protect yourself accordingly. A good quality
paint respirator or a Supplied Air System (SAS) is a must. Never paint
w/o a good respirator. Reports of people dying from paint hardening
up in people's lungs should scare you enough. Don't take risks. Be
sure to paint in a well ventilated area. Also, reduce skin exposure
to thinners and reducers by wearing chemical resistant rubber gloves
when handling paint products. |
| 33. |
Q.
Can I get a good looking job in my garage?
A. Yes. I've seen some fantastic paint jobs that
were done by relatively inexperienced painters in average house garages
and even outdoors. But you must take measures to reduce dust and spray
when conditions are favorable (see more below). |
| 34. |
Q.
What are some tips when spraying in my garage?
A. The secret is good preparation following all
the proper steps and not cutting corners during preparation and painting.
It's also important to take measures to reduce dust. Vacuum dust off
the floor with a shop vac and cover with water before you paint to
hold down dust. Make sure dust won't fall onto the paint from rafters
or lights above the vehicle. Blow off vehicle. Blow off air compressor
so when it starts up halfway through a paint job it doesn't blow dust
all around. Wear a paint suit and head sock so dust from clothes and
hair don't fall into the paint. Make sure you have a sturdy stool
to stand on if necessary. Use wheel covers or cover with plastic bags.
Mask around wheel wells and panel seams to prevent sudden dust from
blowing out of cracks. Paint early in the day rather than later in
the evening when bugs come out. They'll see your shop lights' reflection
in your paint and fly right into it. If you paint outside, do it on
a cloudy day. Don't paint in direct sunlight because the paint surface
will warm up (from the sun) and it won't flow out. It'll look gravely.
And obviously don't paint under trees. |
| 35. |
Q.
What are the mixing ratios of my paint?
A. It varies between paints and manufacturers. Some
common ratios are 1:1(equal parts paint and reducer), 2:1 (two parts
paint to one part reducer), 4:2:1 (four parts primer to two parts
reducer to one part hardener). Clear plastic mixing cups available
where you buy your paint have common ratios and graduations on the
side. They are the most convenient and accurate way to mix paint. |
| 36. |
Q.
What is a paint mixing cup?
A. It's a clear plastic cup with graduated markings
on the side for common mixing ratios. They're inexpensive and available
where you buy your automotive paint. Some painters clean them out
with thinner and reuse them several times. Small mixing cups about
the size of a regular cup are great for mixing small amounts of paint
for small repairs. |
| 37. |
Q.
Should I strain my paint? Why?
A. Yes, it's
very important. It keeps paint particles from clogging your spray
gun and chunks out of your paint. Most paint stores give away paper
paint strainers for free when you buy your paint. strain the mixed
paint before you put it in your gun. You'd think a can of paint would
be free from contaminants, but remember, the paint you buy is actually
mixed from a number of base colors sitting on the paint store's paint
mixer. They pour in x number of grams of this color and some of that
according to a formula. If you've ever seen the special lids on these
cans you'd see gobs of dry crusty accumulated paint hanging off the
pour spout. Small chunks often inadvertantly fall into the paint can
as they pour it out. Any chunks will reek havok with a gravity-feed
gun. Straining paint is just another small step to help ensure a good
paint job. |
| 38. |
Q. How do I get
my paint to flow out well without running?
A. That's the million dollar question. It just
takes practice to get the right touch and a 'feel' for how much
to put on. You have to watch the paint as it's going on. But first,
you must be set up properly. Be sure you have the correct air pressure
at the gun and be sure the reducer you are using matches the temp
you are spraying in. Test the spray pattern on a piece of cardboard
and clean the nozzle if it doesn't appear like a long oval. As for
spraying techniques, when you spray, hold the gun about 8-10"
from the paint surface and perpendicular to it. Pull the trigger
to the first level (no paint should be coming out). Begin moving
your hand and pull the trigger in the rest of the way to allow paint
to come out. Maintain a steady rate of travel and distance to the
paint surface. Travel varies but 4-5 sec/yard is good to get started.
Always make sure the gun nozzle is perpendicular to the surface.
Each pass with the spray gun, the paint spray pattern should overlap
the previous pass by 40-50%.
First, if you're spraying a clearcoat finish, you need to have
the proper spray cap on your spray gun. Read your gun manufacturer's
instructions and use the recommended cap. Older paint guns like
the Binks model 7 or DeVilbiss JGA can't properly atomize clearcoats
to get a nice finish. A #7 air cap can be purchased for the DeVilbiss
JGA spray gun so it will perform properly.
|
| 39. |
Q. What is a sealer
and do I need to use it?
A. It's recommended to use a sealer prior to painting.
Here are some properties of a sealer:
- Creates a uniform color and surface to paint over (important
for metallics)
- Improves paint adhesion
- Creates a barrier to prevent the new paint's solvents from lifting
the old paint
- Fills in sand scratches and other minor surface imperfections
(allows use of courser paper when sanding a vehicle than w/o using
a sealer)
- Tintable to vehicle color (reduces # of paint coats - saves
money)
- Improves paint gloss by deflecting reducers upward
Most sealers are non-sanding and are applied with a single medium-wet
coat just prior to the first coat of paint. Usually after spraying
the sealer, by the time the painter has cleaned the spray gun and
mixed the paint, the sealer is dry enough to be painted over.
|
| 40. |
Q. What is the
best air pressure to spray at?
A. Pressures vary depending on the brand and type
of material you are spraying and your spray gun. You need to know
the gun's nozzle orfice size (eg. 1.4, 1.6, 1.8 cc) and which air
cap it has. Some spray gun manufacturers list the best combination
of tip size, air cap and gun air pressure for various types of paint.
So, check with the manufacturer for the best setup and spray pressures.
Obtain product data sheets from your paint supplier for specific
mixing instructions. Here are some general pressures that apply
to a gravity feed gun:
|
Paint product
|
Pressure - PSI
|
| Self etching primer |
30-35 |
| Epoxy primer |
40-45 |
| High-build primer |
35-40 |
| Sealer |
40-45 |
| Basecoat |
40-45 |
| Clearcoat |
45-50 |
| Acrylic enamel |
55-60 |
| Lacquer |
35-40 |
Many HVLP guns use pressures in the 20-30 psi range.
|
| 41. |
Q.
I got some runs in my paint, now what?
A. You can sand them down and buff them out. If
you do a good job you shouldn't be able to tell. Be aware that if
it's a single-stage paint, you'll remove the thin layer of UV protectant
at it's surface and it will eventually fade quicker in the sanded
and buffed area than the rest of the paint job. If it's in the clear
coat, you'll be ok. |
|
|
