paint gun question
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
Neither. I used a Harbor Freight gun for topcoats on my 77 last week and although it is shiny and looks "OK", I was unable to completely eliminate all surface texture no matter what I tried... the gun is simply incapable of atomizing the paint finely enough for a really "slick" coat. Spend a bit more and get a lot more for your money I say. The DeVilbiss finishline guns get good reviews mostly and are reasonably priced.
Tech Contributor
Joined: Sep 2011
Posts: 109
Likes: 2
From: In the booth Maryland
What your spraying isn't always the most important factor in gun choice. With today's lower VOC paints you can buy an expensive gun and still not get good results.
For compliant urethane clear coats a 1.3 HVLP is a good all around fluid nozzle size. it's also good for most basecoats
For 2K urethane primers a 1.5 or a 1.6 is good
For polyester primer 2.0 to 2.5
HVLP is whats most common, make sure you can supply it with the volume (CFM'S) it needs
LVLP doesn't need alot of air, low overspray means more paint on car not in the air, Iwata is the only maker I know of. High quality=High$$$ I wouldn't trade mine for the world
RP ( reduced pressure ) a cross between HVLP and conventional
I own a really nice Iwata touch up gun but rarely use it, for automotive work I use my full size for almost everything, if a part is big enough to be worried about shine or peel a full size gun throttled back has been the easiest in my experience.
Whatever gun you choose, practice, practice, practice
I have sprayed alot of the guns out there over the years, I prefer SATA and Iwata.
Before VOC laws came into auto painting, most paints were pretty much the same viscosity and behaved the same so the guns of those days stayed current for many years.
In the 90's ( in MD.) paints ( especially clearcoat ) changed to thicker products with less solvent. For a good while alot of painters were turning job that should have a Sunkiss sticker on it, LOTS of orange peel. Up until the VOC change if your paint didn't flow you opened up the fluid nozzle adjustment and hammered more on. What they failed to understand was that the 1.8 nozzles didn't break up the thicker clears, it was explained to me this way" what's smoother a floor covered in beach ***** or golf *****?" So instead of opening up the nozzles they needed to be smaller to atomize better
Spraying clear that lays out like glass takes the proper fliud nozzle size, the proper temp hardner/reducer, the right amount and pressure air, a good spray technique.
Things that will also affect your finished product are stable temp. enough air rolling over the car while spraying, and bunsch of other things that you'll learn spraying in your particular situation.
Shiny clear starts with your primer/sealer, every layer has to be dead smooth or you'll have to go to great lengths to make it right. If your spraying sealer and it's grainy or peely make adjustments. If your done and it's that way get out the 800 dry and level it. Same goes for base, you all the time in the world to let things dry a bit and sand out dirt,runs,peel, etc.
So now you have a uniform, smooth layer of base on your job, knowing how your clear is going to act when you spray it is extremely helpful. With a new gun, a clear you haven't sprayed before in a booth/room thats new is very tricky for me and I've been doing this all my life. Spraying cars isn't rocket science, it's experience. Alot of people can spray a car and have it come out nice when everything goes well and there are so surprises. A guy who sprays 5 jobs a day and has been doing it for years can fix pretty much any problem that happens in the booth and keep going.
Clears from different companies that have a different VOC content act different. Thin clears ( above 4 voc) are easy to spray, you put on more coats, they don't move too much after you spray them piece of cake, they also don't have the depth, clarity and look of a high solid clear job. From there you go up to 2.3 voc clears. They take more effort and experience to lay out. I sprayed a job last week, the base was good, almost shiny, I sprayed the first coat of a high solid clear properly and looks almost like a million fisheyes, the clear hit the panel and sat for a second, the slowly strarted to lay down. Here is where knowing your product is the difference between runs, sags, solvent pops or WOW that looks great. The really high solid clears I've sprayed for collision work are applied by spraying one half coat immediatly followed by a full wet coat. When doing custom/overalls you spray till you think you've got all the clear it'll stand on each coat before running down the panel, then adjust booth temp to get it where you want it. Having a consistant stroke as you go across the panel makes for a better job. If I have one small drip at the bottom of a panel that dries before it hits the floor it's perfect. The perfect paint job is one big run.
I would suggest using a thinner product and putting more coats on if you don't have alot of air movement across the car and aren't expereince with thick clears.
The Horrible freight gun if that's all you can afford can be used to do a good job, just be sure not to use a 1.8 fluid nozzle for base or clear.
Hope this helps, if you have more questions feel free to ask.
SprayGun
For compliant urethane clear coats a 1.3 HVLP is a good all around fluid nozzle size. it's also good for most basecoats
For 2K urethane primers a 1.5 or a 1.6 is good
For polyester primer 2.0 to 2.5
HVLP is whats most common, make sure you can supply it with the volume (CFM'S) it needs
LVLP doesn't need alot of air, low overspray means more paint on car not in the air, Iwata is the only maker I know of. High quality=High$$$ I wouldn't trade mine for the world
RP ( reduced pressure ) a cross between HVLP and conventional
I own a really nice Iwata touch up gun but rarely use it, for automotive work I use my full size for almost everything, if a part is big enough to be worried about shine or peel a full size gun throttled back has been the easiest in my experience.
Whatever gun you choose, practice, practice, practice
I have sprayed alot of the guns out there over the years, I prefer SATA and Iwata.
Before VOC laws came into auto painting, most paints were pretty much the same viscosity and behaved the same so the guns of those days stayed current for many years.
In the 90's ( in MD.) paints ( especially clearcoat ) changed to thicker products with less solvent. For a good while alot of painters were turning job that should have a Sunkiss sticker on it, LOTS of orange peel. Up until the VOC change if your paint didn't flow you opened up the fluid nozzle adjustment and hammered more on. What they failed to understand was that the 1.8 nozzles didn't break up the thicker clears, it was explained to me this way" what's smoother a floor covered in beach ***** or golf *****?" So instead of opening up the nozzles they needed to be smaller to atomize better
Spraying clear that lays out like glass takes the proper fliud nozzle size, the proper temp hardner/reducer, the right amount and pressure air, a good spray technique.
Things that will also affect your finished product are stable temp. enough air rolling over the car while spraying, and bunsch of other things that you'll learn spraying in your particular situation.
Shiny clear starts with your primer/sealer, every layer has to be dead smooth or you'll have to go to great lengths to make it right. If your spraying sealer and it's grainy or peely make adjustments. If your done and it's that way get out the 800 dry and level it. Same goes for base, you all the time in the world to let things dry a bit and sand out dirt,runs,peel, etc.
So now you have a uniform, smooth layer of base on your job, knowing how your clear is going to act when you spray it is extremely helpful. With a new gun, a clear you haven't sprayed before in a booth/room thats new is very tricky for me and I've been doing this all my life. Spraying cars isn't rocket science, it's experience. Alot of people can spray a car and have it come out nice when everything goes well and there are so surprises. A guy who sprays 5 jobs a day and has been doing it for years can fix pretty much any problem that happens in the booth and keep going.
Clears from different companies that have a different VOC content act different. Thin clears ( above 4 voc) are easy to spray, you put on more coats, they don't move too much after you spray them piece of cake, they also don't have the depth, clarity and look of a high solid clear job. From there you go up to 2.3 voc clears. They take more effort and experience to lay out. I sprayed a job last week, the base was good, almost shiny, I sprayed the first coat of a high solid clear properly and looks almost like a million fisheyes, the clear hit the panel and sat for a second, the slowly strarted to lay down. Here is where knowing your product is the difference between runs, sags, solvent pops or WOW that looks great. The really high solid clears I've sprayed for collision work are applied by spraying one half coat immediatly followed by a full wet coat. When doing custom/overalls you spray till you think you've got all the clear it'll stand on each coat before running down the panel, then adjust booth temp to get it where you want it. Having a consistant stroke as you go across the panel makes for a better job. If I have one small drip at the bottom of a panel that dries before it hits the floor it's perfect. The perfect paint job is one big run.
I would suggest using a thinner product and putting more coats on if you don't have alot of air movement across the car and aren't expereince with thick clears.
The Horrible freight gun if that's all you can afford can be used to do a good job, just be sure not to use a 1.8 fluid nozzle for base or clear.
Hope this helps, if you have more questions feel free to ask.
SprayGun
Tech Contributor
Joined: Sep 2011
Posts: 109
Likes: 2
From: In the booth Maryland
PS: there are only a handfull of paint gun manufactures, Snap on, Eastwood and the like are private lable guns from one of the large names. Alot of Sata knock off's are around, most come out of China, quality ranges from good to piece of crap. If your at harbor frieght check the gun you going to buy. I got one a couple years back that didn't have all the holes drilled in the air cap
Drifting
Joined: Feb 2008
Posts: 1,560
Likes: 4
From: Arlington texas
Spraygun,
That was a lot of info that was really good. I want to paint my own car in the future and enjoy hearing someone with experience explain things that weekend hobbyists can understand and learn from.
That was a lot of info that was really good. I want to paint my own car in the future and enjoy hearing someone with experience explain things that weekend hobbyists can understand and learn from.
