[Ratchet]

I am into the final steps on the project and last night I laid down the first pass of clear coat. Using PPG's DCU 2002. It is mixed 4 parts clear 1 part reducer and 1 part hardener.

When I sprayed it on it came out really thick and I had to use a very slow gun motion to apply it and get good coverage. This was ok on the roof and hood as they are flat surfaces. When I went to the sides I got some pretty enormous runs.

The gun is adjusted as best I can get it folowed all the how to guides.

What do I do to make it flow out better so I don't have to apply it so thick?

Can I reduce it a little more?

Ric

[302 Z28]

Yes you can reduce it a little more, but if you do not have good gun control that is only going to make your problems with runs even worse.

Vince

[MARTINSR]

What does "The gun is adjusted as best I can get it folowed all the how to guides." mean?

1. What gun and tip size?
2. How much inlet pressure?
3. What compressor and CFM do you have?

Before adding reducers, lets get a good foundation with gun set up.

Brian

[Ratchet]

Ok the Gun is a GRIP HVLP Gun Tip size is 1.4 and the compressor is 10 cfm and the line pressure is set to 80 psi and then the pressure at the gun is set to 45 when I pull the trigger and hold it it stays steady at 40 psi.

As for the pattern I followed your set up guide held gun about 6-8 inches from paper couldn't see squat. changed to cardboard the brown paper on the cardboard makes it easier to see the pattern.

Again with gun 6-8 inches from the target I opened up the material knob one full turn. then I adjusted the fan to a nice wide fan. then I opened up the material knob about a half and shot a pattern kept doing the open 1/2 turn until I got a nice cigar shaped pattern about 6-8 inches tall.

Went and sprayed about a 12 " test swipe and the material did not fill in at my regular gun speed. I opened up the material knob another half turn and did another test swipe at about half my regular gun speed. Looked ok so on it. went. Bad Idea.

[baddbob]

Sounds like poor atomization, your air supply may not be keeping up with the gun? I'm not familiar with the grip gun but I do know some of these cheaper HVLP guns are definately air pigs. 45psi seems like a lot for an HVLP. Also make sure the clear is stirred really well.

[BarryK]

If the gun adjustments did not do any major changing with fluid adjustment.

Unscrew your aircap and the Fluid tip unscrew and look at the inside where the needle goes, guaranteed you have a spot of dried clear, primer or base in there.

[Ratchet]

Originally Posted by BarryK

If the gun adjustments did not do any major changing with fluid adjustment.

Unscrew your aircap and the Fluid tip unscrew and look at the inside where the needle goes, guaranteed you have a spot of dried clear, primer or base in there.

It is not that the gun adjustments didn't do any thing. As a matter of fact the gun adjustments seemed to work just fine. both fan and fluid levels worked just as they should the problem is that the clear is not atomizing enough. No mater if it is a lot of fluid or a little fluid big fan little fan 50 lbs air pressure 30 pounds air pressure the material comes out with big droplets at the outside of the fan causing poor flow out and surface finish. That is why I wanted to add some additional reducer. 4 parts clear to 1 part hardner and 1 part reducer means if you mix up 12 ounces of sprayable material you only have 2 ounces of reducer in it.


Ric

[BarryK]

Can you get the wall pressure to 100-120?
If you figure a 15lb drop for line your just not getting enough scfms.
Turn wall pressure has high as you can and try a spray pattern.

[MARTINSR]

DO NOT add any more reducer until you figure this out. If you have reduced as per manufacturers recommendations it WILL work. Sure, a little more reducer may help it lay out, but AS RECOMMENDED it WILL work.


Other than your material knob being out too far or you are mistaken somehow on the inlet pressure to the gun, I don't have any ideas for you. But in my opinon, SOMETHING is amiss here and adding more reducer is NOT the solution.

Brian

[BondoKing]

Sounds like really that his compressor is not going to flow enough... I know many of you have already said this, I am just in agreement with you... I have sprayed Concept 2002 with an inadequate air supply and then with adequate, the difference in flow was amazing.... I too could not get it to lay down correctly without the right air system on the other area's of the car besides the roof and hood.... Just my 2 cents

Matthew

[MARTINSR]

Matthew, you may have been able to get it to "flow out" on those horizontal surfaces but it later died back, shrank up and turned a leathery look (even if you had to look real close) I'll bet.

Brian

[baddbob]

It's got to be an air delivery problem, when he adjusts the gun to get the fluid volume needed the air isn't there to atomize it correctly, tough to figure out when the gun isn't in your hand. Sounds like the gun atomizes fine when the fluid amount is low. A 1.3 fluid tip might help? Larger air line with high flow fittings maybe. Or add another 1/2 part reducer and deal with the dieback later. ????

[MARTINSR]

It's the pits when like you say Bob, "the gun isn't in your hand". I am willing to bet this is an easy fix, if only we knew what to ask.

I mean first off, the 10 CFM compressor isn't going to cut it. Most HVLP guns need 13-16 so at 10 advertised (probably closer to 8) you are going to have very poor atomization. But there is more to this I think. The needle doesn't match the nozzle,s like I said "SOMETHING" is a miss.

Ri, What kind of filter? A toilet paper filter will rob five or ten CFM by it's self.

What size hose, and how long? How about the other piping, what does it look like?

Is the clear mixed well in a cup and then poured into the gun?

Do you have a link to some info on this gun? I have never heard of it.

Brian

[bluebu]

Maybe it's just a rookie mistake because I had exactly the same problem when I tried to spray this clear. I could get the gun pattern okay, not perfect, just okay but when I'd try to shoot for real it would orange peel badly. After messing with my gun for over an hour I gave up on it and just played around on a test panel adjusting my distance and speed until I found a method that worked. I ended up holding the gun about 6" out and slowing WAY down. I found that if I really watched the clear hitting the surface I could get it slick but I did feel like I was keeping just ahead of a run. Think I held my breathe the whole time. It was pretty nerve racking!

[Ratchet]

http://www.overstock.com/cgi-bin/d2....prod_id=736570

here is the link to the gun.

I know that the compressor is small for the job and that is probably the root of the problem. To compensate I added another 20 gallon holding tank. So I pump up both tanks which are hooked paralell to each other then I start to spray. By the time I empty a full cup gun and have to refill the gun the compressor has been running this entire time but the gage on the gun never goes below 40 lbs while I am spraying that is with the trigger pulled and running a pass from one end of the car to the other the gauge stays right at 40 psi. that is what is going through the gun.

Maybe I am just expecting too much. I can get it on shinny and smooth for the most part but I inevitably end up with one or two runs due to the amount of material I am putting on the car. I am using a 50% overlap is this wrong for clear coat. Should I only be overlapping until I get full coverage like 25%.

Anyway it is going to turn out ok it is shinny and fairly smooth, not like glass it is kind of wavy with the waves being about 1/2 inch in frequency and the amplitude is only a about .1 mill so a good sanding and buffing will look after most of it. There are a couple of bugs in it right now along with a small scattering of specs of dust so I guess it will need to be sanded and buffed anyway.

I am going to put a finall coat on it tonight I will lightly sand out the tiny dirt nibs and the rest of the two bugs that didn't come out with the tweasers. Say a prayer and try to lay down the final coat nice and smooth.

Ric