DarrelK wrote:Whoa......back the truck up here....You had the gun set at WHAT? 12 p.s.i......????? Don't those guns call for a minimum of 23 p.s.i. with a full trigger pull?????

If it is the Finish Line 4 and the #3 Air Cap (HVLP), I think the factory says: 13 CFM @23 psi.

The #1 Air Cap (conventional) says: 9.9 CFM @40 psi at the inlet.

I know because I was supprised as I have the #3 Air Cap and I run mine with primers and sealers at 2 bars (28 psi), and it seems to work good.

Oh dear! Where do I start?

Let's start with gun pressure. Firstly, I really don't understand why so many people persevere with HVLP unless it's mandated. Obviously not in this case since spraying outside. 12psi might be the recommended pressure, but that's at the aircap, not at the inlet. RP guns are much more efficient, transferring more product to the surface with less going to atmosphere. They also generally use much less air and are capable of much better finishes. Out of the 20 or so guns that I own there is only one that is HVLP and that's a mini gun with 1.00mm setup that I use mainly for blending clear.

See the charts on this page. Although the FLG4 isn't actually listed (not classed by Devilbiss as a professional gun?) there are inlet pressures for various others, including HVLP and you will note that they range, typically, around 24-26psi.

So, at 12psi you're waaay too low. That's going to be a major contributor to that finish because you're simply not atomising the paint.

It also looks like you're holding the gun too far out, making the problem even worse. At the right pressures the air cap needs to be in around 150mm from the surface. This will slam the paint on and help it to stick and flow out, giving a wetter, flatter finish.

Sanding. Hard to see from the pictures, but if there are sanding marks under the clear then they'll be poor preparation on primer or substrate. I really don't like to go coarser then P800 wet. Although some say P600 is ok, and you may get away with it on solid colours, the risks, IMHO, are too high. The primer or substrate that you're painting base over needs to be flat, no peel. If you don't go far enough then any imperfections will amplify with subsequent coats.

When sanding there are a couple of golden rules. Firstly, unless absolutely impossible, alwats use a block. Looking at the sanding scratches in the pictures I can see finger marks. Using a block will avoid these. Secondly, if you absolutely cannot use a block the sand side to side, not in line with your fingers. Again this will even the sanding action. Never sand in circles. Also make sure that your paper is clean and you have enough water to flush away any grit which will contribute to the bigger scratches than can be seen in the pictures.

So, what to do? First option is to continue blocking the surface out with P1200 wet until it's level, then P1500/P2000 and maybe P3000. Then buff. There is a risk of cutting through but you may have enough clear on there.

Alternately, cut the worst of the orange peel out and reclear. If there are sanding scratches under the existing clear you can dust some more colour over those areas first.

Buffing. A DA will not cut it when buffing. Literally. Some electric random orbital machines have the power, with the right pads, to work, but I prefer a rotary for this stage. You can go to random orbital later to address swirl.

Toyota (even Lexus) paint isn't so good out of the factory that you need to get a perfectly flat finish which will look different to the factory peel. Some peel is going to actually be better. Accept that and follow what I've said above on pressure and technique and "off the gun" may well be good enough.

NFT5 wrote:Oh dear! Where do I start?

Let's start with gun pressure. Firstly, I really don't understand why so many people persevere with HVLP unless it's mandated. Obviously not in this case since spraying outside. 12psi might be the recommended pressure, but that's at the aircap, not at the inlet. RP guns are much more efficient, transferring more product to the surface with less going to atmosphere. They also generally use much less air and are capable of much better finishes. Out of the 20 or so guns that I own there is only one that is HVLP and that's a mini gun with 1.00mm setup that I use mainly for blending clear.

See the charts on this page. Although the FLG4 isn't actually listed (not classed by Devilbiss as a professional gun?) there are inlet pressures for various others, including HVLP and you will note that they range, typically, around 24-26psi.

So, at 12psi you're waaay too low. That's going to be a major contributor to that finish because you're simply not atomising the paint.

It also looks like you're holding the gun too far out, making the problem even worse. At the right pressures the air cap needs to be in around 150mm from the surface. This will slam the paint on and help it to stick and flow out, giving a wetter, flatter finish.

Sanding. Hard to see from the pictures, but if there are sanding marks under the clear then they'll be poor preparation on primer or substrate. I really don't like to go coarser then P800 wet. Although some say P600 is ok, and you may get away with it on solid colours, the risks, IMHO, are too high. The primer or substrate that you're painting base over needs to be flat, no peel. If you don't go far enough then any imperfections will amplify with subsequent coats.

When sanding there are a couple of golden rules. Firstly, unless absolutely impossible, alwats use a block. Looking at the sanding scratches in the pictures I can see finger marks. Using a block will avoid these. Secondly, if you absolutely cannot use a block the sand side to side, not in line with your fingers. Again this will even the sanding action. Never sand in circles. Also make sure that your paper is clean and you have enough water to flush away any grit which will contribute to the bigger scratches than can be seen in the pictures.

So, what to do? First option is to continue blocking the surface out with P1200 wet until it's level, then P1500/P2000 and maybe P3000. Then buff. There is a risk of cutting through but you may have enough clear on there.

Alternately, cut the worst of the orange peel out and reclear. If there are sanding scratches under the existing clear you can dust some more colour over those areas first.

Buffing. A DA will not cut it when buffing. Literally. Some electric random orbital machines have the power, with the right pads, to work, but I prefer a rotary for this stage. You can go to random orbital later to address swirl.

Toyota (even Lexus) paint isn't so good out of the factory that you need to get a perfectly flat finish which will look different to the factory peel. Some peel is going to actually be better. Accept that and follow what I've said above on pressure and technique and "off the gun" may well be good enough.

I see that you've been at this a long time (20 guns?) and this is great advice. I tried leveling out everything but went into the base because of all of the mistakes that I made from the start. Wind, low pressure, peeled base etc. I have to start from scratch again. If you can add anything to an already great response I'd fully appreciate it. Going in for the last time.

OldFatBald wrote:

DarrelK wrote:Whoa......back the truck up here....You had the gun set at WHAT? 12 p.s.i......????? Don't those guns call for a minimum of 23 p.s.i. with a full trigger pull?????

If it is the Finish Line 4 and the #3 Air Cap (HVLP), I think the factory says: 13 CFM @23 psi.

The #1 Air Cap (conventional) says: 9.9 CFM @40 psi at the inlet.

I know because I was supprised as I have the #3 Air Cap and I run mine with primers and sealers at 2 bars (28 psi), and it seems to work good.

I was watching some Aussie video where he was set at 12. My dumb mistake and I should have known better.

rambrosi wrote:(20 guns?)

Yeah. Sad isn't it? Even the ones I class as fails I keep because there's some use for them. Only the Devilbiss Starting Line guns went into the bin, a long time ago, since there was no possibility of them ever being any use. Strange how a name brand manufacturer of such good stuff could possibly have come up with such garbage - even worse than the cheap Chinese junk that sometimes actually sprays ok. Trying out the latest, a GTi Pro Lite, this afternoon on a bonnet, 2 guards and 2 doors on a Corolla.

If you've already cut through then there's no choice but a rework. Cut it all back flat with P800 and then just spot prime where you went through. If you used grey primer then just spot out the primed areas with base before going all over with just 2 coats. Then clear, after sorting out pressures and technique, as above. On a bonnet it should flow out if wet enough and not too hot.

My FLG4 Finishline manual says to set air to 23PSI to start with the #3 cap. I think at 12 PSI it just dribbles out the end.

Before you start up again... watch like 20 videos on how to setup your gun. Then get a roll of brown paper from your big box store, fill the gun with water instead of paint, and learn how to set the gun up. You will be amazed what a little practice can do.

BeoBob wrote:Before you start up again... watch like 20 videos on how to setup your gun. Then get a roll of brown paper from your big box store, fill the gun with water instead of paint, and learn how to set the gun up. You will be amazed what a little practice can do.

I thank you all for your great advice when I am done I will repost my results with pictures wish me luck

NFT5 wrote:

rambrosi wrote:(20 guns?)

Yeah. Sad isn't it? Even the ones I class as fails I keep because there's some use for them. Only the Devilbiss Starting Line guns went into the bin, a long time ago, since there was no possibility of them ever being any use. Strange how a name brand manufacturer of such good stuff could possibly have come up with such garbage - even worse than the cheap Chinese junk that sometimes actually sprays ok. Trying out the latest, a GTi Pro Lite, this afternoon on a bonnet, 2 guards and 2 doors on a Corolla.

If you've already cut through then there's no choice but a rework. Cut it all back flat with P800 and then just spot prime where you went through. If you used grey primer then just spot out the primed areas with base before going all over with just 2 coats. Then clear, after sorting out pressures and technique, as above. On a bonnet it should flow out if wet enough and not too hot.

Only 20 ? Begginer...

HaHa just poking fun brother