my adventures in painting the car thread, DONE! Some final thoughts... Options

[mb911]

Prepsol should be allowed to dry /evaporate before spraying anything over it. I wait a good 15 minutes but apply wet then dry with 2 separate rags and then allow the 15 minute air dry.

[914 RZ-1]

Don’t overlook the quality of your compressed air if you’re having flaws in your finish. A filter/regulator mounted right at the compressor tank with a hose to your spray gun is likely not enough to eliminate moisture and oil that can spit out and cause fisheyes or what might be blamed on solvent pop. I don’t know what you have for a compressed air system but it’s important to trap the water and oil that can really screw up an otherwise nice paint job.

I've got a 25' coiled hose from the tank to 2 moisture filters on the wall. It then goes out to a coiled 50' hose. I got a "pumpkin" filter at the gun.

Interestingly, whenever I purge the moisture filters on the wall, no fluid comes out. When I purge the tank, I do get a bunch of orange water.

Compressor is 8.6/6.4 cfm @40/90 psi. 2 (running, not peak!) HP, 33 gallon.

[914 RZ-1]

Here's the latest:

I painted both doors. I put on 2 coats, one right after the other while it was still wet. They both look pretty good except for some orange peel in a few places. It doesn't seem as bad as before. I'll try sanding it out. It looked really good when I first sprayed it, then as it dried the orange peel appeared.

The gun was intermittently not spraying paint, but otherwise it went well.

It was 85-90 degrees, 45% humidity at 9 am.

[Andyrew]

What kind of gun with what size tip are you spraying with?

[Andyrew]

Don’t overlook the quality of your compressed air if you’re having flaws in your finish. A filter/regulator mounted right at the compressor tank with a hose to your spray gun is likely not enough to eliminate moisture and oil that can spit out and cause fisheyes or what might be blamed on solvent pop. I don’t know what you have for a compressed air system but it’s important to trap the water and oil that can really screw up an otherwise nice paint job.

I've got a 25' coiled hose from the tank to 2 moisture filters on the wall. It then goes out to a coiled 50' hose. I got a "pumpkin" filter at the gun.

Interestingly, whenever I purge the moisture filters on the wall, no fluid comes out. When I purge the tank, I do get a bunch of orange water.

Compressor is 8.6/6.4 cfm @40/90 psi. 2 (running, not peak!) HP, 33 gallon.

I always buy a new filter from HF whenever spraying. This type. It will grab all moisture. I have used JUST this filter before without issue for minor work. I replace it after the media starts to change color.
https://www.harborfreight.com/inline-desicc...lter-68215.html

[Costa05]

I thought I read in one of your posts that you were running 10 to 15 psi at the gun which is real low. 25 to 30 psi is better. From what I have learned from the net is 10 psi is at the tip of the gun but is unmeasursble. The pressure must be sustained obviously and with small compressors that can be difficult to do. Thus small parts its ok. A good test is release just air out of gun, set the pressure, and continue releasing while watching the gauge see just how fast it drops off on you. I had a 20 gal compressor once that gave maybe enough time for one coat on a small fender at the required pressure. It got way better with my 60 gallon.

[914 RZ-1]

What kind of gun with what size tip are you spraying with?

This one, with a 1.4 tip:
https://www.harborfreight.com/20-oz-profess...-gun-68843.html

I thought I would try a cheap gun first, then buy a nicer one, but this one seems to work fine. Everything I read said it's really the technique, not just the gun, that makes for a good spray job.

[914 RZ-1]

Don’t overlook the quality of your compressed air if you’re having flaws in your finish. A filter/regulator mounted right at the compressor tank with a hose to your spray gun is likely not enough to eliminate moisture and oil that can spit out and cause fisheyes or what might be blamed on solvent pop. I don’t know what you have for a compressed air system but it’s important to trap the water and oil that can really screw up an otherwise nice paint job.

I've got a 25' coiled hose from the tank to 2 moisture filters on the wall. It then goes out to a coiled 50' hose. I got a "pumpkin" filter at the gun.

Interestingly, whenever I purge the moisture filters on the wall, no fluid comes out. When I purge the tank, I do get a bunch of orange water.

Compressor is 8.6/6.4 cfm @40/90 psi. 2 (running, not peak!) HP, 33 gallon.

I always buy a new filter from HF whenever spraying. This type. It will grab all moisture. I have used JUST this filter before without issue for minor work. I replace it after the media starts to change color.
https://www.harborfreight.com/inline-desicc...lter-68215.html

Thanks, I'll look at this one. I think I need a new filter anyway. I was using the red "pumpkin" filters.

[914 RZ-1]

I thought I read in one of your posts that you were running 10 to 15 psi at the gun which is real low. 25 to 30 psi is better. From what I have learned from the net is 10 psi is at the tip of the gun but is unmeasursble. The pressure must be sustained obviously and with small compressors that can be difficult to do. Thus small parts its ok. A good test is release just air out of gun, set the pressure, and continue releasing while watching the gauge see just how fast it drops off on you. I had a 20 gal compressor once that gave maybe enough time for one coat on a small fender at the required pressure. It got way better with my 60 gallon.

Yeah, I was spraying at that before I learned my lesson. I upped the psi at the gun to 30 and got much better results. I didn't realize how much pressure drop there was. The air even sounds different.

I did just what you suggest: I pressed and held the trigger to see what the pressure was staying at. Before, I just pressed and released and got about 30 psi, but that was just a burst. It would go down to 10 or so when I held the trigger for spraying. My gauge was covered with paint, then when I cleaned it with acetone, the plastic got fogged up. I sanded with 2000 and polished it up so I could see it again.

I don't get as much paint on anything, like I did before, so I've been able to see the gauge while spraying.

[Andyrew]

What kind of gun with what size tip are you spraying with?

This one, with a 1.4 tip:
https://www.harborfreight.com/20-oz-profess...-gun-68843.html

I thought I would try a cheap gun first, then buy a nicer one, but this one seems to work fine. Everything I read said it's really the technique, not just the gun, that makes for a good spray job.

Thats certainly a good enough gun. The purple $15 guns are junk, but that one is good enough. My $600 gun works only a hair better than my $80 gun.

[aggiezig]

You already have a ton of great feedback on this thread but I thought I would add my $0.02 as well from my introductory painting experience.

First off, I am not a fan of HF guns for spraying topcoats. Some of the more experienced guys can make this work but I just don't think those guns have enough adjustment and do a good job of atomizing paint. That's just my opinion. I bought a devilbiss starting line gun kit. Two guns and accessories for under $200.

It sounds like you are using the right temp reducer, but when in doubt always choose the slower (higher temp) reducer and just allow more flash time between coats to avoid solvent pop.

PSI at the gun should be 35-40 with the trigger depressed. Make sure you are setting this pressure correctly, it can greatly affect your outcome. As others have mentioned, make sure your air is clean.

Make sure you are applying medium wet coats with a good 50% overlap. If you aren't getting enough paint on the panel, it will never get a chance to flow out. A lot of times I have to remind myself to slow down when spraying.

After spraying 3-4 coats of color, give the paint a full 24 hours to shrink up and flash before assessing orange peel and other conditions. It takes time for the paint to reach it's final appearance state but it's 80-90% of the way there about a day afterwords.

When wet-sanding, start around 1000-1200 and work up in stages. 1000 - 1500 - 2000, etc. You will need either rotary buffer (dangerous to novice users) or a dual action with enough throw and aggressive pads to get ALL of the sanding marks out. I can general get around 95-98% correction with my dual action using a microfiber cutting pad and meguiars M105 cutting compound. Tape off your edges when sanding!

I'm sure there are other tips I can think of but that's a fair amount of information for now. Your last efforts look much better than when you started. This isn't an easy trade to master, but with a lot of practice and perseverance you can get pretty good at spraying paint as a hobbyist.

[Costa05]

I thought I read in one of your posts that you were running 10 to 15 psi at the gun which is real low. 25 to 30 psi is better. From what I have learned from the net is 10 psi is at the tip of the gun but is unmeasursble. The pressure must be sustained obviously and with small compressors that can be difficult to do. Thus small parts its ok. A good test is release just air out of gun, set the pressure, and continue releasing while watching the gauge see just how fast it drops off on you. I had a 20 gal compressor once that gave maybe enough time for one coat on a small fender at the required pressure. It got way better with my 60 gallon.

Yeah, I was spraying at that before I learned my lesson. I upped the psi at the gun to 30 and got much better results. I didn't realize how much pressure drop there was. The air even sounds different.

I did just what you suggest: I pressed and held the trigger to see what the pressure was staying at. Before, I just pressed and released and got about 30 psi, but that was just a burst. It would go down to 10 or so when I held the trigger for spraying. My gauge was covered with paint, then when I cleaned it with acetone, the plastic got fogged up. I sanded with 2000 and polished it up so I could see it again.

I don't get as much paint on anything, like I did before, so I've been able to see the gauge while spraying.

Thats great. Check out the Eastwood videos on youtube. I think the guys name is Kevin Tetz. He is pretty good at teaching how to paint. Also good you mounted gauge right at your gun. Even if it clouded over due to solvent. (IMG:style_emoticons/default/beerchug.gif)

[aggiezig]

Thats great. Check out the Eastwood videos on youtube. I think the guys name is Kevin Tetz. He is pretty good at teaching how to paint. Also good you mounted gauge right at your gun. Even if it clouded over due to solvent. (IMG:style_emoticons/default/beerchug.gif)

+1 for Kevin Tetz videos. The guy is extremely talented, down to earth and does a great job of explaining basics. I've watched probably hours of the eastwood videos on youtube before jumping off the cliff.

[bbrock]

Thats great. Check out the Eastwood videos on youtube. I think the guys name is Kevin Tetz. He is pretty good at teaching how to paint. Also good you mounted gauge right at your gun. Even if it clouded over due to solvent. (IMG:style_emoticons/default/beerchug.gif)

+1 for Kevin Tetz videos. The guy is extremely talented, down to earth and does a great job of explaining basics. I've watched probably hours of the eastwood videos on youtube before jumping off the cliff.

+2 on Tetz. Kinda hooked on his vids.

[914 RZ-1]

What kind of gun with what size tip are you spraying with?

This one, with a 1.4 tip:
https://www.harborfreight.com/20-oz-profess...-gun-68843.html

I thought I would try a cheap gun first, then buy a nicer one, but this one seems to work fine. Everything I read said it's really the technique, not just the gun, that makes for a good spray job.

Thats certainly a good enough gun. The purple $15 guns are junk, but that one is good enough. My $600 gun works only a hair better than my $80 gun.

I actually used a purple gun to spray catalyzed paint (basically spray-on fiberglass) on my targa top. I sanded thru it and needed to fix it and this was the best way. I figured I'd ruin a cheap gun. It actually worked pretty good.

I read in several places about how the cheap guns can spray as good as the expensive ones.

[914 RZ-1]

You already have a ton of great feedback on this thread but I thought I would add my $0.02 as well from my introductory painting experience.

First off, I am not a fan of HF guns for spraying topcoats. Some of the more experienced guys can make this work but I just don't think those guns have enough adjustment and do a good job of atomizing paint. That's just my opinion. I bought a devilbiss starting line gun kit. Two guns and accessories for under $200.

It sounds like you are using the right temp reducer, but when in doubt always choose the slower (higher temp) reducer and just allow more flash time between coats to avoid solvent pop.

PSI at the gun should be 35-40 with the trigger depressed. Make sure you are setting this pressure correctly, it can greatly affect your outcome. As others have mentioned, make sure your air is clean.

Make sure you are applying medium wet coats with a good 50% overlap. If you aren't getting enough paint on the panel, it will never get a chance to flow out. A lot of times I have to remind myself to slow down when spraying.

After spraying 3-4 coats of color, give the paint a full 24 hours to shrink up and flash before assessing orange peel and other conditions. It takes time for the paint to reach it's final appearance state but it's 80-90% of the way there about a day afterwords.

When wet-sanding, start around 1000-1200 and work up in stages. 1000 - 1500 - 2000, etc. You will need either rotary buffer (dangerous to novice users) or a dual action with enough throw and aggressive pads to get ALL of the sanding marks out. I can general get around 95-98% correction with my dual action using a microfiber cutting pad and meguiars M105 cutting compound. Tape off your edges when sanding!

I'm sure there are other tips I can think of but that's a fair amount of information for now. Your last efforts look much better than when you started. This isn't an easy trade to master, but with a lot of practice and perseverance you can get pretty good at spraying paint as a hobbyist.

Thanks for the advice. Always appreciated! (IMG:style_emoticons/default/beerchug.gif) Where were you a few months ago! (IMG:style_emoticons/default/poke.gif)

Yeah, I use the slower reducer. I can wait.

I noticed the psi has a huge effect. I'm just an idiot and didn't do this right the first few times. I now check the psi with the trigger depressed.

I never did find any good advice on how fast to move the gun. I tend to go too fast on the big panels. I noticed on the small pieces I was getting a good finish; I was going fast over them.

I sand by hand unless I'm re-painting a panel. I've burned thru the paint too easily. I've even sanded thru it by hand, especially on the edges. Once I get a good finish, I will tape the edges.

I should have practiced more! (IMG:style_emoticons/default/headbang.gif)

[914 RZ-1]

+3 on Kevin Tetz. I learned most of this from his videos. I also bought some sanding supplies and tools from Eastwood. I just wish they had 800, 1000, 1500 and 2000 grit for the long Durablocks. Their house brand sandpaper is pretty good. I'm using 3M and it works, but clogs and wears out fast, even though I'm using water.

[mbseto]

Man this is a clinic. Almost makes me want to try to paint my own car.

[IronHillRestorations]

FWIW, I have separate air hoses for only paint use.

[mepstein]

+3 on Kevin Tetz. I learned most of this from his videos. I also bought some sanding supplies and tools from Eastwood. I just wish they had 800, 1000, 1500 and 2000 grit for the long Durablocks. Their house brand sandpaper is pretty good. I'm using 3M and it works, but clogs and wears out fast, even though I'm using water.

We buy all our supplies from a local automotive paint shop. It's worth getting the high quality stuff. Much more selection and we can pick up stuff as we need it. Actually, they deliver for free twice a day.