Tiger striped my first paint job

Slofut said:
If you got a tiny spray pattern you're gonna have tiger stripes.
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I can't afford a new gun or compressor this time, but I decided I'm gonna bump up the pressure and fluid when I respray to give me a bigger pattern. But ya it's been torture trying to use it for an overall
 
Painther said:
I can't afford a new gun or compressor this time, but I decided I'm gonna bump up the pressure and fluid when I respray to give me a bigger pattern. But ya it's been torture trying to use it for an overall
Click to expand...
Your spray gun as two air requirements. First is CFM which is the volume of air the gun needs to function properly, the second is the PSI which is the pressure at which the CFM is needed.

If your spray gun requires 13 CFM at 30 PSI and your compressor only puts out 7 CFM at that pressure, then you are going to have issues. Jacking the pressure up does not increase the volume of air.

I started out with a small compressor and kept having issues, finally broke down and bought a larger, two stage compressor. .
 
'68 Coronet R/T said:
If your spray gun requires 13 CFM at 30 PSI and your compressor only puts out 7 CFM at that pressure, then you are going to have issues.
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That is true if you are spraying continuously - or for longer than the combination of the tank and compressor can supply the required CFM.

But, the combination of the tank and compressor will deliver whatever the CFM the tool demands for some period of time - maybe only a few minutes. Depends on the tank size, compressor CFM output and the tool demand.

See this example:
13 CFM HVLP Gun
30 gallon tank
6.2 CFM compressor output
Tank cutoff pressure 175 PSI

It will supply the gun for 12.2 minutes and recover in 5.5 minutes. That might be sufficient for some situations if you are willing to work around the compressor.

compressor example.jpg


I created this tool to help with this:

compressor sizing guide - Black Diamond

**I am part of the Amazon Associates program. Any purchases made from product links may generate a commission.
blackdiamondblocks.com blackdiamondblocks.com
 
'68 Coronet R/T said:
Your spray gun as two air requirements. First is CFM which is the volume of air the gun needs to function properly, the second is the PSI which is the pressure at which the CFM is needed.

If your spray gun requires 13 CFM at 30 PSI and your compressor only puts out 7 CFM at that pressure, then you are going to have issues. Jacking the pressure up does not increase the volume of air.

I started out with a small compressor and kept having issues, finally broke down and bought a larger, two stage compressor. .
Click to expand...
The specs for the lvlp I'm using says it uses 3-4 cfm, but I'm guessing more like 5. So I'm right at the limit for sure.
When the funds are right I am absolutely going to upgrade my compressor and gun
 
Dean Jenkins said:
That is true if you are spraying continuously - or for longer than the combination of the tank and compressor can supply the required CFM.

But, the combination of the tank and compressor will deliver whatever the CFM the tool demands for some period of time - maybe only a few minutes. Depends on the tank size, compressor CFM output and the tool demand.

See this example:
13 CFM HVLP Gun
30 gallon tank
6.2 CFM compressor output
Tank cutoff pressure 175 PSI

It will supply the gun for 12.2 minutes and recover in 5.5 minutes. That might be sufficient for some situations if you are willing to work around the compressor.

View attachment 39873

I created this tool to help with this:

compressor sizing guide - Black Diamond

**I am part of the Amazon Associates program. Any purchases made from product links may generate a commission.
blackdiamondblocks.com blackdiamondblocks.com
Click to expand...
Luckily I was somewhat proactive with the research and connected another large tank, so it doesn't really fluctuate pressure or run out while spraying the whole car. But the trade off is 14-18 psi while spraying my base and that leaves me with a 4 inch fan. So I was thinking of spraying my base a little wetter this time with more psi, I noticed it makes the fan pattern about 2 inches longer. Here's a picture of my setup, excuse the mess. Lmao
1000004784.jpg
1000004785.jpg
 
BrianK said:
You can rent a small 20cfm gas compressor in my area for about $65 a day, a larger 90cfm diesel tow-behind runs about $200.. might be worth looking into
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would you paint with a towable compressor? i been after one for years, just for blasting. they bring a lot at sales. almost had one of those half a ford engine set ups once but got outbid at the last second. i am not a skilled bidder lol.
 
Treeslayer said:
would you paint with a towable compressor? i been after one for years, just for blasting. they bring a lot at sales. almost had one of those half a ford engine set ups once but got outbid at the last second. i am not a skilled bidder lol.
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If you setup your lines correctly and could have it outside or in an enclosed or partially enclosed area outside of the workplace it should do fine. Noisy though I would imagine
 
Switched up my setup so it actually functions correctly now! Have a stainless flex pipe going from the compressor motor straight to the 50 feet of copper pipe, through a air/water separator and back into the compressor tank. The copper pipe is cooling off the air like a champ, allowing the water to get pulled out. Then into the auxillary tank and finally the 3 stage filter. Did a test by filling everything up, and no matter how long I spray it will maintain a constant air pressure, even at 35 psi. I realize that heat builds up which equals moisture, but I'm confident we're good to go for another try. Bought an r500 also, the spray pattern is way bigger. Sanding down with 800 grit and respraying soon, I'll keep you guys posted.

I appreciate the help from everyone
 
'68 Coronet R/T said:
I took my signature car to a body and paint class that a local college offered. After I had shot 3 coats of base on the car, the instructor took some base coat and added extra reducer to it. He then held the spray gun about 16-18" from the car surface and sprayed what he called a dust coat (or something like that), which he said would give the metallic a nice even look.

Hopefully some of the pros on here will comment on this technique.
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I'm not a pro obviously, but Barry taught me the drop coat back in 2014. It saved my ass on a severely striped metallic I was painting (which was my first complete and a difficult color). Any time I've done a metallic since then, I also do a final drop coat immediately over the last wet coat of base just in case, though my striping issue was something that sorted itself out after I realized how closely the LPH400 needs to be held to the panel, and once I started using 75% overlap.

4" panel distance, 75% overlap, faster passes letting the overlap fill it in a little more each time ended up fixing my poor technique.
 
Painther said:
Switched up my setup so it actually functions correctly now! Have a stainless flex pipe going from the compressor motor straight to the 50 feet of copper pipe, through a air/water separator and back into the compressor tank. The copper pipe is cooling off the air like a champ, allowing the water to get pulled out. Then into the auxillary tank and finally the 3 stage filter. Did a test by filling everything up, and no matter how long I spray it will maintain a constant air pressure, even at 35 psi. I realize that heat builds up which equals moisture, but I'm confident we're good to go for another try. Bought an r500 also, the spray pattern is way bigger. Sanding down with 800 grit and respraying soon, I'll keep you guys posted.

I appreciate the help from everyone
Click to expand...
I highly suggest a motor guard M30 for a final moisture filter maybe 40 or so ft from the gun. I've had very good results using it and you can find a good deal on them, but I get really dry air from an otherwise marginal system, it makes me happy, money well spent.
 
Lizer said:
I'm not a pro obviously, but Barry taught me the drop coat back in 2014. It saved my ass on a severely striped metallic I was painting (which was my first complete and a difficult color). Any time I've done a metallic since then, I also do a final drop coat immediately over the last wet coat of base just in case, though my striping issue was something that sorted itself out after I realized how closely the LPH400 needs to be held to the panel, and once I started using 75% overlap.

4" panel distance, 75% overlap, faster passes letting the overlap fill it in a little more each time ended up fixing my poor technique.
Click to expand...

Agreed. The 4" distance is hard to get used to at first but what a difference as the paint flows out.

My first attempt at this distance was spraying clear coat on this hood. I was terrified that I would have runs all over the place but it was amazing that I could see the clear flow together and the orange peel disappear.
This was a truck hood so not a show car and hence I was able to put this on the truck without any cut or buff.
ColorasSprayed.jpg


TruckFrontAfter.jpg
 
Lizer said:
I'm not a pro obviously, but Barry taught me the drop coat back in 2014. It saved my ass on a severely striped metallic I was painting (which was my first complete and a difficult color). Any time I've done a metallic since then, I also do a final drop coat immediately over the last wet coat of base just in case, though my striping issue was something that sorted itself out after I realized how closely the LPH400 needs to be held to the panel, and once I started using 75% overlap.

4" panel distance, 75% overlap, faster passes letting the overlap fill it in a little more each time ended up fixing my poor technique.
Click to expand...
Thank you for the heads up! I'll give this technique a shot on my test hood before spraying the car again. I did try to spray a couple drop coats after the first coverage coats but I think the stripes were just too obvious to be fixed at that point. I even did alternating directions but I'm pretty sure that gun distance and overlap is what killed me, I was so scared of getting mottling that striping never crossed my mind. Now I know to check it over with the shop lights off before clear! Hahaha, live and learn. Thanks again bro
 
'68 Coronet R/T said:
Agreed. The 4" distance is hard to get used to at first but what a difference as the paint flows out.

My first attempt at this distance was spraying clear coat on this hood. I was terrified that I would have runs all over the place but it was amazing that I could see the clear flow together and the orange peel disappear.
This was a truck hood so not a show car and hence I was able to put this on the truck without any cut or buff.
View attachment 40360

View attachment 40362
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Damn! That looks great, I'd be more than happy with an outcome like that, especially straight off the gun. I'll practice a bit before the respray and try not to be scared this time!
 
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