MARTINSR, other painters?

I have painted several cars now and none of them have come out without paint that did not need buffed to get a good shine. What in blue blazes am I doing wrong?

Clear coat I have sprayed goes on much nicer, but still needs buffing to get a real shine.

Dave

No matter how good a painter you are, to get a super slick show quality finish you have to wet sand and buff. Are you not getting any shine before those steps?
What brand and types of paint have you used?
There's a good chance that it's the gun or the application methods. Did you read MartinSr's post on atomization? Very good reading if you haven't already. Are you measuring air pressure at the gun?
Whay kind of gun are you using?

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MY 69 (http://www.chevelles.com/cgi-bin/xchange/xchange.cgi?search_and_display_db_button=on&db_id=22&exact_match=on&photo_size=full)

You gotta lay some clear on that thing!Theres a fine line between a great shine and runs and sags. http://www.chevelles.com/forum/biggrin.gif I see a lot of people scared to death of runs,so they put the clear on real dry.Don't be scared.

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jimmy P:
No matter how good a painter you are, to get a super slick show quality finish you have to wet sand and buff. Are you not getting any shine before those steps?
What brand and types of paint have you used?
There's a good chance that it's the gun or the application methods. Did you read MartinSr's post on atomization? Very good reading if you haven't already. Are you measuring air pressure at the gun?
Whay kind of gun are you using?
<HR></BLOCKQUOTE>

Jimmy:
I get a shine before blocking and buffing, but nothing like even the most average factory paint job.
Yes, I did read MARTINSRs post. Printed it out and tried to follow to the letter. It did help, but still not happy with the initial paint shine.
I am experimenting with air at the gun now. I have a regulator right at the gun and am using an HVLP gravity feed. I started with 55 psi at the gun and am now down to 40. What I am trying to do is get the adomization as fine as I can and still throw enough paint to cover in a reasonable amount of time with a shine.
Using Martin Sr. paint and MSA reducer/hardener. MSA has the Martin Sr. logo and is supposedly packaged by Martin Sr.

70isfine:
I'm not scared to put paint on, believe me.
I have blocked out my share of runs. I am trying to put the paint on to look the way I want it when it dries. Starts off nice and shiny and eventually looses its gloss to some extent. Seems to shrink a lot too. I am mixing paint to exact specs on the cans with hardner, so I don't think there is too much solvent. I see almost the same problem with clear, although not nearly as bad.
I know I am doing something wrong, but I just don't know what.

Dave

[This message has been edited by SS_Dave (edited 04-09-2002).]

Dave, if you have gone down to 40 lbs, you are going the wrong way. The lower the pressure the LESS it will be atomized and the more solvent you will dump into the film.

Tell me something is it "die back" we are talking about? How does it look the minute you are done spraying? If it looks good then and then the next day or two is when it looses it's shine, it is die back caused by eccessive solvent in the paint.

MSA (Martin-Senour Acrylic) is Sherwin Williams "Western" brand. Martin Senour products are ALL Sherwin Williams products with a different label. Sort of like a 2002 Mazda Pickup IS a Ford Ranger with a different emblem on it. Or a Geo Prizm IS a Toyota Corrolla with a different emblem.


MSA is a lower end paint, though I have been very happy with results from it. I wonder if you are expecting a shine like you would get with a urethane or bc/cc and you are simply asking too much of the MSA?


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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

<BLOCKQUOTE>quote:</font><HR>Originally posted by MARTINSR:
How does it look the minute you are done spraying? If it looks good then and then the next day or two is when it looses it's shine, it is die back caused by eccessive solvent in the paint.
<HR></BLOCKQUOTE>

Minute I am done, looks great. My expectations soar and the next day reality
sets in. http://www.chevelles.com/forum/frown.gif The finish almost turns into a semi-gloss. Sounds like it is "die back".
If I am mixing according to the can, why did it do this?

<BLOCKQUOTE>quote:</font><HR>
I wonder if you are expecting a shine like you would get with a urethane or bc/cc and you are simply asking too much of the MSA?

I whish that were the case. However, you do bring up a good point though. Maybe I will be switching to urethanes instead of the Acryllic Enamels. I would like to be able to shoot a decent paint job without blocking and buffing with the Acryllics. I'll try the higher air psi route.

[/B]<HR></BLOCKQUOTE>

Thanks for the input MARTINSR. http://www.chevelles.com/forum/smile.gif

Dave, go back and read the "Atomization basics" again, I cover it there. The solvent is being trapped in the film and after the top surface drys a little it "glazes" over. Then the solvents that are trapped break through like weeds comeing through blacktop.

It comes down to these factors:

Too slow of reducer (flashes do slow the top has time to glaze over before it leaves)

Too fast of a reducer (Flashes so fast on the surface that the top glazes over while excessive solvent is trapped.

Too heavy of an application (too much solvent plain and simple)

Too low air pressure ( Same as above, too much solvent because it is not broken up)

Too much material (too many coats or it may include too much sealer and or primer depending on when they were applied)

1K Sealers or primers that are sucking up the solvents till the top glazes over and they are trapped.

does anything ring a bell?

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

Dave, you don't mention the conditions under which you are spraying. It makes a huge difference. Since all of the newer Urethane BC/CC paint sytems were designed for use in a heated, downdraft booth, I can easily achieve a finish as smooth,or even smoother than late model factory finises. I use Spies/Hecker 8000 clear with a Sata NR95, cranked up to about 60 lbs., well over the green indicator on the gauge. With this combination, I only need to nib sand and polish out the light dust for even a high end car finish.
However, painting in a garage or other similar situation is a completely different matter. First, I try to achieve a decent air flow with attic fans in the ceiling. Then, with the same Sata NR95 and a Spies/Hecker 1- coat clear, (8110), I spray on one good coat of the clear. Then, the next day or so, I sand the clear smooth with 1000 sandpaper. Then apply the final coat of clear. By using this one coat at a time process, very little dirt gets into the clear, leaving an easy buff job to get an outstanding finish. In case you are wondering, applying these (Sies/Hecker) clears in this way, you will have as much material on the panels as other brands get with several coats.

Gordon VM
Restoration Motorsports

Man, that is a very good point Gordon! I forgot all about air movement, in a garage that can be a killer.
If you have a booth you normally would leave the booth running long after the car is shot to help "pull" out the solvents from the paint.

If you paint in a garage and then walk out and leave the door shut, your solvents can't get out. The air in the garage is all filled with solvent very fast and the solvent left in the paint has no where to go.

Plus the overspray in the garage falls back onto the surface and dries it up, it is a loser either way.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

That little trick you mentioned Gordon is a great one. I learned that one about 10 years go from a Ferrari/Porcshe/custom - high end refinisher in Ft. Lauderdale. I was at a transmission shop waiting for a trans for about 6 hours (long story) and this place was next door. At first I watched, then I made conversation. Then I asked questions, then I got some GREAT info, first hand. That's how they did ALL of their paint. They were doing a 46 Ford when I was there. Since it was an older car that needed a lot of straightening, after the primer was blocked down they would apply two coats of a color in urethane, then let it dry for few days. Then, they blcked sanded with a stick (5 gallon stir stick cut up) to get a super slick straight finish, removing most of the color coat. Then the base color was applied and first coat of clear went on. Dried for a few days and applied two more coats of clear. This clear was over a brandywine metallic. I saw the car when it was finished at a show. WOW! Now I realize and others must also, that over a grand of materials was used on this car in paint alone. But the results showed it.
I've been copying those guys stuff ever since. Amazing what you can learn when you're in the right place and someone is willing to share.

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MY 69 (http://www.chevelles.com/cgi-bin/xchange/xchange.cgi?search_and_display_db_button=on&db_id=22&exact_match=on&photo_size=full)

Dave, Martin SR may have just nailed your problem. "Die back" due to not enough air flow after you are done spraying. Those of us who are professionals, do this as second nature without even thinking. We hit the "Bake" button or if painting in a garage, leave the fan on for several minutes after spraying.
Jimmy, You're right. The process I mentioned is really not new. Some paint manufacturers teach this method as means of achieving "buffless" paint work. Spies/Hecker even has a section in their tech book utilizing this method for restoration. The thing to remember though is, on a custom or restoration paint job, you will still need to buff your work to get perfection. An even if you get some die back, you can still revive it with a buffer.
Gordon VM
Restoration Motorsports
http://communities.msn.com/Restorationphotos/shoebox.msnw

I agree with the movement of air being vital to the reaction process. Fresh air has to be involved in order for you base or clear to flash off. I do however think that the extra steps in sanding the intial coat of clear with 1000 or any grit in not needed. paints/clears today do not require this extra step, at least in PPG or Dupont. The nice thing about BC/CC is that you can stop at any time during the base and fix your mistakes. Clear is meant to flow with several coats upon each other. My advise is to contact your paints' technician where you bought the product and tell them about your specific problem. These tech's spend many hours learning about their products in different inviroments. Good luck

MARTINSR, Gordon:

I think between the two of you, you have nailed my problem. Poor atomization and no air movement. I only paint small pieces in my garage because I have no exhaust fan. I shoot the part and then open all the garage doors trying to get the overspray out. As soon as most is out, I close the doors. I know, what do I expect. The truth eventually comes out, huh? I see now that with all the previous jobs I have done, it was one thing or the other that caused the problems.
I will be experimenting with this new knowledge and more air pressure.

Thanks for all the input. http://www.chevelles.com/forum/smile.gif

Dave