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Paint problems 101:

 
Old 11-21-2011, 08:27 PM
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Spraygun
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Default Paint problems 101:

Spraying auto paint is not difficult, doesn't require a lot of training, it's a fairly simple process.
Spraying auto paint to achieve a high gloss finish with even color and 100% coverage is another story. Most anyone who puts their mind to it can spray a tractor or some lawn furniture and get the desired results. Painting a car that you love and want to look good takes some practice, research and info from people who already know how to do it.
Aside from your prep and mask there are certain problems you can run into while spraying.

Dirt:
Dust and grit can come from 3 main sources, a dirty booth, a dirty car or a dirty painter. Cleaning your booth is straight forward, taking precautions to make sure to air being drawn into the booth takes some filtration. Spray booths have intake filters and exhaust filters. Intake filters are responsible for removing dust and dirt from air being drawn over the car while spraying. They are available from paint supply stores and are not cost prohibitive. You'll need to know how much air your planning on drawing to size them properly, then mount them in such a way that all incoming air goes through them.
The prepped car should be cleaned inside and out before painting. After sanding a car has dust in every crack and crevice imaginable, high pressure air should be used to blow out every surface, jamb, panel, hole, etc. It sometimes takes 4-5 times blowing a car off before no traces of dust are seen while blowing.
The painter should be free of dust while in booth, a paint suit is a good idea to prevent dirt in paint and for safety.
How a car is masked can cut down on dirt, tape up all holes, jambs, wheel wells, etc to keep dust from blowing out on to to paint your spraying.


Fisheyes:
The surface your painting needs to free of any silicon, grease, wax, amour all, tire dressing, etc. Fisheyes are small round areas where the paint could not adhere because silicon/wax prevented it A car should be degreased with a wax and grease remover as soon as it enters the shop. Waiting until it's time to paint to degrease is not a good idea. If there are wax, silicone, etc. on the car sanding will grind them into the substrate making it difficult to remove.



Runs, sags, dry spots, orange peel:
Spray technique, equipment choice, product choice all come into play when it's time to start spraying. If you have never painted before or you have limited experience, don't attempt to spray your car without practice. Things like spraygun adjustment and air pressure will make the difference between, OMG that's sweet! and going to buy more sandpaper to prep again. Painting a car is a fine balance between temp, gun choice, gun adjustment, product choice, reduction, air flow, painter spray speed. I have been painting for 25+ years and I still get a sag or a run from time time. It's been said that " The perfect paint job is one big run" maybe 20 tears ago but I'm not sure that holds true with todays products. Higher solids catalyzed paints are more sensitive than products of the past. A huge factor in weather you get runs is how much solvent blows off the RTS material in the time it takes to get from the gun to the car. A given amount (varies by product) needs to leave the RTS material or it will run off the panel. Air pressure comes into play here, more air in-less solvent on car. Air pressure and fluid nozzle choice are also key in atomizing the paint well, improper atomization causes orange peel.
How do you learn to paint? same as most things, PRACTICE PRACTICE PRACTICE. Most good painters I know have no formal training, me included. I watched guys spray, bought a spraygun and started painting things. You should do the same. You'll never learn to clear a hood and have turn out shiny and beautiful reading tech manuals. It's not rocket science, if you can speak in complete sentences, you can paint. Old hoods/fenders, friends beater cars, sheets of metal are all good things to practice on.
There seems to be an endless supply of people wanting their cars painted for cheap/free, they aren't interested in quality, just price. It's good practice and you might make a couple bucks, or get a new obsession.. I was an electrician with a hot rod in primer, once I got to see the car go from primer to painted I was hooked. The satisfaction and gratification of taking soemthing ugly and making it beautiful is what keeps me painting, and of course the money$.
SG
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Old 06-01-2012, 12:53 AM
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alonzomerrill
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Originally Posted by Spraygun View Post
Spraying auto paint is not difficult, doesn't require a lot of training, it's a fairly simple process.
Spraying auto paint to achieve a high gloss finish with even color and 100% coverage is another story. Most anyone who puts their mind to it can spray a tractor or some lawn furniture and get the desired results. Painting a car that you love and want to look good takes some practice, research and info from people who already know how to do it.
Aside from your prep and mask there are certain problems you can run into while spraying.

Dirt:
Dust and grit can come from 3 main sources, a dirty booth, a dirty car or a dirty painter. Cleaning your booth is straight forward, taking precautions to make sure to air being drawn into the booth takes some filtration. Spray booths have intake filters and exhaust filters. Intake filters are responsible for removing dust and dirt from air being drawn over the car while spraying. They are available from paint supply stores and are not cost prohibitive. You'll need to know how much air your planning on drawing to size them properly, then mount them in such a way that all incoming air goes through them.
The prepped car should be cleaned inside and out before painting. After sanding a car has dust in every crack and crevice imaginable, high pressure air should be used to blow out every surface, jamb, panel, hole, etc. It sometimes takes 4-5 times blowing a car off before no traces of dust are seen while blowing.
The painter should be free of dust while in booth, a paint suit is a good idea to prevent dirt in paint and for safety.
How a car is masked can cut down on dirt, tape up all holes, jambs, wheel wells, etc to keep dust from blowing out on to to paint your spraying.


Fisheyes:
The surface your painting needs to free of any silicon, grease, wax, amour all, tire dressing, etc. Fisheyes are small round areas where the paint could not adhere because silicon/wax prevented it A car should be degreased with a wax and grease remover as soon as it enters the shop. Waiting until it's time to paint to degrease is not a good idea. If there are wax, silicone, etc. on the car sanding will grind them into the substrate making it difficult to remove.



Runs, sags, dry spots, orange peel:
Spray technique, equipment choice, product choice all come into play when it's time to start spraying. If you have never painted before or you have limited experience, don't attempt to spray your car without practice. Things like spraygun adjustment and air pressure will make the difference between, OMG that's sweet! and going to buy more sandpaper to prep again. Painting a car is a fine balance between temp, gun choice, gun adjustment, product choice, reduction, air flow, painter spray speed. I have been painting for 25+ years and I still get a sag or a run from time time. It's been said that " The perfect paint job is one big run" maybe 20 tears ago but I'm not sure that holds true with todays products. Higher solids catalyzed paints are more sensitive than products of the past. A huge factor in weather you get runs is how much solvent blows off the RTS material in the time it takes to get from the gun to the car. A given amount (varies by product) needs to leave the RTS material or it will run off the panel. Air pressure comes into play here, more air in-less solvent on car. Air pressure and fluid nozzle choice are also key in atomizing the paint well, improper atomization causes orange peel.
How do you learn to paint? same as most things, PRACTICE PRACTICE PRACTICE. Most good painters I know have no formal training, me included. I watched guys spray, bought a spraygun and started painting things. You should do the same. You'll never learn to clear a hood and have turn out shiny and beautiful reading tech manuals. It's not rocket science, if you can speak in complete sentences, you can paint. Old hoods/fenders, friends beater cars, sheets of metal are all good things to practice on.
There seems to be an endless supply of people wanting their cars painted for cheap/free, they aren't interested in quality, just price. It's good practice and you might make a couple bucks, or get a new obsession.. I was an electrician with a hot rod in primer, once I got to see the car go from primer to painted I was hooked. The satisfaction and gratification of taking soemthing ugly and making it beautiful is what keeps me painting, and of course the money$.
SG
I have read your all information about painting and all detail is very helpful and definitely i will follow it. Before go start learning painting, i want to know that how much practice needed to become a good painter.
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Old 06-16-2014, 12:57 AM
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I have been painting for a production collision shop for about 5 years. One of the biggest thing is to clean car and area you will paint vary vary will. If you miss a spot that you dint blow off before you start painting I guarantee it will come out when your paint gun blowers on it. If your environment is a dirty area wet down floor and walls, this will keep dust down.

As for products used I was trained with PPG waterborne paint and to be honest I would never go back to solvent based paint. Waterborne doesn't react nearly as easy to fisheye or lifting issues. its as if water isn't as picky as solvent based and you can watch water dry from a blue tint when its wet and then it dries to your color you are spraying. Know the Primer; Sealer; and Clear are still solvent.

Gun choice, I have a couple SATA 3000, but there pricey ($600 NEW). I did just by another gone that is a SATA knock off that I think works awesome. I can not remember the name but I only paid $200 for it. I can PM any body that wants me to get the name for you.

One last bit of info. Get comfortable in your suit and mask. don't rush yourself during the prepping/masking and painting the car.
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Old 02-02-2015, 05:03 PM
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86C4Z51
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Start by building plastic models. Get yourself a dual action airbrush and paint those. If you can do all the details on those, and get a good paint job, you're well on your way.

Then experiment with metallic finishes and clear coats, or colored gloss "clear" coats. I learned a lot by doing that. Yet I'm still no expert...
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Old 02-03-2015, 05:40 PM
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Originally Posted by 86C4Z51 View Post
Start by building plastic models. Get yourself a dual action airbrush and paint those. If you can do all the details on those, and get a good paint job, you're well on your way.

Then experiment with metallic finishes and clear coats, or colored gloss "clear" coats. I learned a lot by doing that. Yet I'm still no expert...
partially. Learning how to fully utilize a dual action air brush is a good talent to obtain...that is FOR SURE. But instead of investing in a dual action air brush...because the dynamics of using a dual action air brush is not the same as a production paint gun....people need to know how to correctly paint something with an aerosol can FIRST. You would be surprised on how many people cant paint worth a crap with a 'rattle can'. If you can not MASTER a 'rattle can'...do not even pick up any other type of spray equipment.

Painting with all the above (dual action air brush, production paint gun and aerosol cans)..I can say that REALLY using a dual action air brush take the most dexterity and concentration....especially when I an doing a mural or fine shading.

DUB
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Old 02-04-2015, 10:23 AM
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86C4Z51
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Good points, Dub.

Good lighting from all directions is also REQUIRED. If you can't see what your paint is doing, it'll do something you don't want it to!
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Old 02-04-2015, 05:17 PM
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Originally Posted by 86C4Z51 View Post
Good points, Dub.

Good lighting from all directions is also REQUIRED. If you can't see what your paint is doing, it'll do something you don't want it to!
100,000,000,000%

WATCHING the paint at the point of contact is so important.

It is similar to what I have told the guys I have trained in the past. I can handle a run or a sag...I don't like it....but it happens in some areas...we are HUMAN.....BUT 'dry spray' is COMPLETELY unacceptable. That lets me know you were not LOOKING at the paint or clear when it was being applied or where you had applied it.

DUB
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