Body and Paint Questions

[bearman]

67 Coronet let me get this correct. First you prime
Second wetsand prime
Third you use a sealer
Forth wetsand sealer
And last of all you apply paint.

 

[snakeoil24]

Bearman First Straighten metal.
Do your plastic work.
Sand Plastic work
Prime 2x
Block sand with ridgid block 220
Prime again possibly 2 more times.
Block with 320
Guide coat
Block with 320 or 400
Spray body with Body wash, walk the car with Fluorescent light looking for any imperfections.
Spot any small stuff.
Sealer
Light block 600
Wipe down with Body wash
Apply three coats base
Apply 2 coats clear
wet sand 800
Wipe down with acetone
3 more coats clear

 

[Detroit Iron]

Bearman First Straighten metal.
Do your plastic work.
Sand Plastic work
Prime 2x
Block sand with ridgid block 220
Prime again possibly 2 more times.
Block with 320
Guide coat
Block with 320 or 400
Spray body with Body wash, walk the car with Fluorescent light looking for any imperfections.
Spot any small stuff.
Sealer
Light block 600
Wipe down with Body wash
Apply three coats base
Apply 2 coats clear
wet sand 800
Wipe down with acetone
3 more coats clear

And THAT is why paint jobs cost what they cost!

 

[bearman]

Bearman First Straighten metal.
Do your plastic work.
Sand Plastic work
Prime 2x
Block sand with ridgid block 220
Prime again possibly 2 more times.
Block with 320
Guide coat
Block with 320 or 400
Spray body with Body wash, walk the car with Fluorescent light looking for any imperfections.
Spot any small stuff.
Sealer
Light block 600
Wipe down with Body wash
Apply three coats base
Apply 2 coats clear
wet sand 800
Wipe down with acetone
3 more coats clear[/QUOTEo
Thank you so when I get done I should have some great looking arms also haha.

 

[snakeoil24]

You will be very sore for sure it is a lot of work. Any body man doing this long enough gets very beat up.

 

[snakeoil24]

And THAT is why paint jobs cost what they cost!

That is the absolute truth!

 

[1967coronet]

67 Coronet let me get this correct. First you prime
Second wetsand prime
Third you use a sealer
Forth wetsand sealer
And last of all you apply paint.

Pretty much as snakeoil discribed, we differ a little in a couple areas but all in all pretty dang close.
Thats the classics , restos , ect.
Insurance / late model work is a little faster.

 

[440 4 speed]

Don’t know how well the long flat ones would work on a 66-67 Charger or B-body. The painter that did our car said he does not ever want to another 66-67 b-body. Didn’t realize just how many angles, curves and body lines there are in the early Chargers. But he will do the later b-bodies.

 

[snakeoil24]

67 charger required a lot more fine blocking with a straight edge and many more sprays with body wash looking for irregularities. you could spend 400 hours blocking and need twice more when your going to do as a do it yourselfer

 

[Detroit Iron]

So my first attempt at painting a car was a disaster. I've painted engine compartments, wheels and random parts with great success. Today I set out to paint only the roof and had two problems spraying the single stage. I would like input on my issues.

Runs: I got runs on the sail panels. This problem is pretty obvious. I put too much material down at one time. I think I didn't wait long enough between coats. I understand single stage likes to have a base tacky coat, then two wet coats in five minute intervals. Correct?

Orange Peel: I sanded, primed, sealed and blocked to 400, so I don't think this was a prep problem. I think it's more of a technique problem. My guess is too much PSI. I sprayed at about 20psi.

I would also like input on how to correct my screw ups. Can I sand out the runs, re-block the orange peel and then just scuff the rest and repaint?

 

[bearman]

First off I would like to thank you for sharing this. Knowing the goods and bads is awesome. With the input that will guide you in the right way will also be thankful.
My input maybe wrong but this is what I would make sure it is totally dry then take 800grit on a da sander and do the whole roof then finish off 1200 wet sand let dry and clean.
Paint gun would be set trigger pulled at 30 psi adjust to have more product come out and test on a paper until you get it the way you like the flow. Also would be 8to10inches away from the roof when spraying. Put down one light coat wait 5 minutes then put down second coat a little more heavier wait again then finish off with final coat same as second coat.
Most important is the final step must be done correctly. Go into house get a cold beer and relax. Others may have a better way and they're pros follow their advise first on how to do it except for the final step. I'm sure I got that one correct.

 

[Builderguy]

Single stage can be bite you every now and then. Runs: They can be caused by caused by too much material (as in your stroke got slower or paused for a second) but they can also be caused by your reducer. You want the material to be thin so it sprays out very fine for better coverage but too thin and it can run. Follow the spec sheet to a "T" and this is usually eliminated. Orange Peel: Can be caused by the coat your spraying over being too dry. Finger test on some masked off area right next to a panel. If it smears, you need to wait a little longer. If it sticks a little to your finger and pulls some strands, that is just about right. If you leave a finger print and nothing else, you waited too long. It is not so much time, as it is how the paint is setting up (temp and humidity have a huge impact). I never liked the base coat tacky followed by two wet coats 5 minutes apart idea. I spray it all the same (two medium wet coats and done) but I take extra time on the last coat to watch my overlap. Basically the last coat is spray it like you want it to look, cause that is how it is going to end up. A second cause for orange peel can be with atomization. The paint droplets/particles are too big. Make sure your tip size is correct for the product you are using. Too big and you can get nasty orange peel. I tend to use the smallest tip the tech sheet mentions. Since you have sprayed other parts with great success you technique is probably not the problem. I would check your mix ratios and such along with the tip size. Good luck and keep swinging, it only makes you better. Lighter in the wallet, but better.

 

[Detroit Iron]

A lot of the orange peel has smoothed out as it dried. Many areas of the roof look amazing. Some areas have a bit of orange peel. In the past I've sprayed at about 25 psi. The instructions that came with the paint said to spray at 7 psi. I never sprayed that low, so I went lower than 25, but a little more than 7.

I will need to re paint the roof because of the runs on the sail panels.

 

[Builderguy]

You have to watch the psi recommended. The 7 psi you are seeing is at the cap, not at the gun. For my gun I need to run 30 PSIG at the gun to get 10 psi at the cap. I don't spray at that 30 psig I drop it to 26-28 and adjust from there. But, depending on your gun, you may need up to 40 psig at the gun to get 8-10 psi at the cap. I am always checking my gauge on the gun handle to make sure it hasn't drifted even with a push down lock feature. I also use a brand new moisture trap at the gun each time I spray color. I only use these once, and then relegate them to primer only use. Cheap insurance to prevent er a water droplet in your finish color coat.

 

[Builderguy]

Just a little follow up on cap vs gun pressure because it can be confusing:

Unless you have specialized test equipment, you will not be able to measure this pressure "at the air cap". For HVLP guns, an equivalent pressure "at the gun inlet" that will result in a maximum 10 psig "at the air cap" should be given in the documentation that came with the gun; or stamped on the gun handle itself. My HVLP spot gun has this inlet pressure stamped on the handle as 29 psig max. This is interpreted to mean when I have 29 psig at the inlet to the gun, with the trigger pulled, the cap pressure will be no more than 10 psig and the legal requirement for HVLP will be met. It does not mean that the gun will be harmed if you increase the pressure (within reason of course)...only that you may be breaking some law, depending on your situation and location.

HVLP gun inlet pressures required to keep the cap pressure at a maximum of 10 psig are different, depending on gun manufacturers. I think about 30 psig is typical but I have read about pressures as low as 15 and as high as 50 psig. Because these pressures are different with different guns, the paint manufacturers cannot give an HVLP inlet pressure in their paint technical data sheets. They can only say a maximum of 10 psig for HVLP, in order to comply with legal requirements. A good tech sheet will tie it down to 10 psig "at the cap". A poor tech sheet will just say 10 psig and leave it up to the reader to know what it means. For HVLP, you need to get the correct gun pressure from the gun manufacturer and not the paint manufacturer.
http://personalpages.tds.net/~thomp...ired to keep the,as 15 and as high as 50 psig.

 

[Detroit Iron]

You have to watch the psi recommended. The 7 psi you are seeing is at the cap, not at the gun. For my gun I need to run 30 PSIG at the gun to get 10 psi at the cap. I don't spray at that 30 psig I drop it to 26-28 and adjust from there. But, depending on your gun, you may need up to 40 psig at the gun to get 8-10 psi at the cap. I am always checking my gauge on the gun handle to make sure it hasn't drifted even with a push down lock feature. I also use a brand new moisture trap at the gun each time I spray color. I only use these once, and then relegate them to primer only use. Cheap insurance to prevent er a water droplet in your finish color coat.

So maybe my problem today was not enough PSI. How would you recommend I move forward with repainting the roof? Sand the runs and just scuff the rest with a Scotch Brite, then respray?

 

[Builderguy]

Scotch Brite pads, I know some people really like them, but I don't (too inconsistent as they start to clog) as you want a really even sub-surface. Since you probably blocked the car for a long time, why mess up all that hard work with a pad? I would go over it all with 400 grit on a board. Your paint product may recommend a different grit (500, 600, ???). Use what they ask for. You can use a DA if that makes life easier, but I like hand sanding to finish even when I use a DA. Once you are done sanding, use some wax and grease remover wiped on very heavy, or even spritz it out of a spray bottle. The wet look and lots of light will show you how it is going to look when done (or at least close). Like what you see, let her rip. See some ripples or waves, sand some more. Unless you sand through somewhere you probably wont have to re-primer it. Just make sure the current paint has time to set up before you start sanding or you will be fighting a battle you can't win.