Painting procedure

[V8PunkRocket]

I have decided to try painting my firewall and inner fenders myself, to see if I might be able to tackle other parts of the car as well.

My question is about the procedure and layers of paint needed. I keep hearing this about etching, primer, basecoast, etc. I have been adviced to go with a basecoat/clearcoat system, and I probably will.

Here are my questions. I realize that I may have not given enough info to answer them, I just don't know enough about this yet...but I suppose asking questions is how you learn!

So, after the body work is done, what do you do next? What is "etching"?

What type of primer should I use? And after I sand it, do I need another coat of primer?

Do I sand the basecoat after I spray it, and then buff it shiny? How many coats of basecoat are typically required?

Do you need to sand/buff clearcoat?

Thanks for any information/advice. I'll post pics of the results when I finally get to that point!

[Shua57]

I have decided to try painting my firewall and inner fenders myself, to see if I might be able to tackle other parts of the car as well.

My question is about the procedure and layers of paint needed. I keep hearing this about etching, primer, basecoast, etc. I have been adviced to go with a basecoat/clearcoat system, and I probably will.

Here are my questions. I realize that I may have not given enough info to answer them, I just don't know enough about this yet...but I suppose asking questions is how you learn!

So, after the body work is done, what do you do next? What is "etching"?

What type of primer should I use? And after I sand it, do I need another coat of primer?

Do I sand the basecoat after I spray it, and then buff it shiny? How many coats of basecoat are typically required?

Do you need to sand/buff clearcoat?

Thanks for any information/advice. I'll post pics of the results when I finally get to that point!

It's actually etching primer. It digs deep into existing paint and will allow a better bond for the new paint. If you are painting over old paint then you would use etching primer. If it is bare metal then you would use a basic primer. )I would recommend using the same company's primer as the paint you buy.) Then there is a sealer primer. Its good to use over fillers or fiberglass. It really just seals anything under it so it will not absorb the basecoat. I would recommend 2 to 3 coats of primer.

The basecoat - I usually lay down 3 coats for the basecoat. I sand the first 2 and don't sand the last. As long as the first 2 coats are sanded correctly, the third will have a very fine texture and will allow the clear to bind with it better. Then you spray your clears on and then use a buffing compound and buff it to a shine.

I just did a motorcycle tank with an acrylic enamel and thought I would not clear it to see how the paint would hold up. It doesn't, gas makes it look like crap. Now I have to wet sand the acrylic enamel and shoot another layer on and then clear it, then buff it and be done with it.

Disclaimer::D
The information the shua (Josh) provides is not always correct and should never be taken to be factual. Sometimes Shua is blowing smoke and doesn't have a clue.

[V8PunkRocket]

hehe well it sounds good to me. I will have some fillers/glass material in the panels I will be painting, so I suppose I will use a sealing primer.

is the color of the primer used relevant to the color of the basecoat? Meaning that if you are going with a blue basecoat, should there be a specific color of primer used?

[Chevynut]

It's actually etching primer. It digs deep into existing paint and will allow a better bond for the new paint. If you are painting over old paint then you would use etching primer. If it is bare metal then you would use a basic primer. )

Actually, that is backward;) . Etch primer has an acid in it that etches the metal to promote primer adhesion. It will not etch paint, but it may not adhere well to paint either. Personally, I would rather use a metal prep (phosphoric acid solution) and epoxy primer which is what I'm doing on my Nomad. I think the epoxy primer adheres better to most surfaces and forms a moisture barrier. Etch or "wash" primer usually cannot be used over other paints or fillers (although some brands can).

Then there is a sealer primer. Its good to use over fillers or fiberglass. It really just seals anything under it so it will not absorb the basecoat.

A sealer is used just before shooting your basecoat. Usually it's a tinted or untinted epoxy primer.


The basecoat - I usually lay down 3 coats for the basecoat. I sand the first 2 and don't sand the last. As long as the first 2 coats are sanded correctly, the third will have a very fine texture and will allow the clear to bind with it better.

You should not have to sand the basecoat. If you sand the underlying primer correctly, the basecoat should cover nicely with no further sanding.

The way I think is best is to get the body to bare metal, then metal prep and shoot with epoxy primer. Epoxy primer doesn't sand well. Then shoot your sandable primer/surfacer (urethane, not lacquer)over it and finish sanding. Then you shoot your topcoat over that. The topcoat can be BC/CC or single stage. A sealer coat CAN be used before topcoating, but is not required. Filler can be used below or on top of the initial epoxy primer.

Disclaimer: I have not painted a car with today's new materials, but I have read a lot about this and I stayed at the Holiday Inn. :D

[Shua57]

hehe well it sounds good to me. I will have some fillers/glass material in the panels I will be painting, so I suppose I will use a sealing primer.

is the color of the primer used relevant to the color of the basecoat? Meaning that if you are going with a blue basecoat, should there be a specific color of primer used?

I usually use the grey but I believe you can get primer tinted. There is also black primer. The color of primer will affect the basecoat. For instance the paint will appear darker over a black primer than over a grey or white. Most people seam to go with a grey since it is neutural. I would go with grey.

Disclaimer:
The disclaimer is to long, see above post....:D

[Shua57]

Actually, that is backward;) . Etch primer has an acid in it that etches the metal to promote primer adhesion. It will not etch paint, but it may not adhere well to paint either. Personally, I would rather use a metal prep (phosphoric acid solution) and epoxy primer which is what I'm doing on my Nomad. I think the epoxy primer adheres better to most surfaces and forms a moisture barrier. Etch or "wash" primer usually cannot be used over other paints or fillers (although some brands can).

I had to look it up. You got me. I have never used Etching primer but I was close HA
Etching Primer: A primer with ingredients that etch into bare metal for better adhesion, also referred to as self-etching primer. Primarily used to prep bare metal.


A sealer is used just before shooting your basecoat. Usually it's a tinted or untinted epoxy primer.

Sealing Primer: A primer used to isolate the existing substrate, or to provide some filling and surface enhancement under the final finish.

You should not have to sand the basecoat. If you sand the underlying primer correctly, the basecoat should cover nicely with no further sanding.

Who said I ever did anything right?:D That subject seems to be one of those "just depends on who you ask".

The way I think is best is to get the body to bare metal, then metal prep and shoot with epoxy primer. Epoxy primer doesn't sand well. Then shoot your sandable primer/surfacer (urethane, not lacquer)over it and finish sanding. Then you shoot your topcoat over that. The topcoat can be BC/CC or single stage. A sealer coat CAN be used before topcoating, but is not required. Filler can be used below or on top of the initial epoxy primer.

I would go with a primer/sealer instead of a primer/surfacer. Primer/sealer is more stable and you can tint it with your base coat. Here is a link to the process from carcraft http://www.carcraft.com/howto/24820/ that should help.

Disclaimer: I have not painted a car with today's new materials, but I have read a lot about this and I stayed at the Holiday Inn. :D

Dislaimer: I need to stop talking and I also have read alot about painting. Unfortunately I can't remember any of it.:( and I have not stayed at the Holiday Inn :(

[alans 55]

my 55 has both bc/cc and single stage enamel on it. (look at the picture in your thread about under hood pictures or go to my album linked below) I painted under the hood, interior, and bottom of the car with single stage enamel w/hardner matched to the base coat for the outer. did for several reasons, if you shoot it correctly it goes on as smooth as bc/cc and nothing else is needed. if you chip or scratch it can be easily touched up as compared to bc/cc. over all it's less expensive as bc/cc when you add up all the items. as Laz (chevynut) said the prep and primer is as important as the finish coat. when I did my 55 I used over 4 gallon of primer and as a rule to include fillers, most was sanded off and put on the floor.

go with the best you can afford. I have shot both the good and cheap and in some cases the cheap is as good or better than 1st line. used to use a lot of centari, but now has been replaced by nasons. I like it cause it goes on easy and lays well. a good gun is also a prerequisite. you will need some type of booth or enclosed area with good ventalation and most important is your own well being with respirtory protection.

painting is a whole lot different than years ago when you just painted either in the garage or in the driveway. watch out for treehuggers that would turn you in if they saw you painting without all the current epa requirements. haven't heard of anyone but who knows they can and will.

prime it good, sand it good, prep it good, paint it good and you are there. don't get discouraged, but do your homework 1st.

regards,

alan

[DONZIE]

HELLO V8
THE BEST ADVISE I CAN GIVE WOULD BE FOR YOU TO JOIN THE PROPER FORUM & READ READ READ & THEN ASK QUESTIONS.
TRY THIS FORUM
http://spi.forumup.org/index.php?mforum=spi

THE VERY BASICS GO
1 SAND WITH "80 GRIT" OR AS RECOMMENDED BY PAINT MANUFACTURER
2 EPOXY PRIMER
3 BODY FILLER
4 SEALER / EPOXY PRIMER
5 POLYESTER PRIMER
6 BLOCK SAND TO PERFECTION
7 FINISH COAT IF SINGLESTAGE - BASE COAT IF BC CC
8 CLEAR COAT
AGAIN - THE VERY BASICS LOTS OF OTHER THINGS MAY BE REQUIRED DEPENDING
DONZIE

[DONZIE]

ALSO - IF THIS IS YOUR FIRST PAINT JOB I WOULD SUGGEST GOING WITH A SINGLE STAGE PRODUCT. IT IS SIMPLER & CHEAPER TO DEAL WITH, LESS EXPENSIVE TO REPAIR SCREWUPS ETC.
DONZIE

[Rick_L]

It may be easier - i.e., less steps - to repair or touch up a single stage paint job - it's much easier to repair a bc/cc paint job and get professional results. That's why it's the choice of body shops.

As for some of the other comments, I don't know where to start.

As said, etch is for bare metal.

I don't know of any bc/cc system where you sand the base. If you do, you essentially have to start over.

Sealers can be in many forms. Usually when the term sealer is used, we're talking of something shot over primer just before topcoat. Sealers are not meant to be sanded prior to topcoat. Epoxy primer can be used as sealer, but it's not the only thing used. You can also use 2k primer surfacer. With either, you usually add more reducer than usually called for as primer. This gives you a finish that does not NEED to be sanded. There are also non-catalyzed sealers - but you don't want to use these with catalyzed primers or topcoats!

One of the main purposes of "sealer" is to give a uniform color to the body/panel prior to topcoat. If you don't have sand through's in your final coat of primer, you don't really need sealer.

Usually, sealer or final primer color should somewhat match your top coat shade/color. This helps your color coat hide and be uniform with fewer coats. I.e., if you're painting white or a light color, you don't want black or dark grey or red sealer. Dupont has tintable primer/sealer recommendations for their colors. PPG has several colors of epoxy primer. Light colors over dark primer are not part of this. On the other hand, dark colors over light primer isn't as bad.

Hope all this makes sense - no doubt there will be more discussion.