Hi guys,

I came across a lot of useful info all from this site, plenty from DarrelK especially. Thank you all for sharing your experience. It's been difficult to search for turbine-specific information, most of it came from this site i think.

I just bought the fuji 2 stage. Tried spraying 1k acrylic just now, didn't go too well. The clear dries before it hits the surface if i hold it at 6", and comes out looking like cotton candy. I have to put the gun really close, maybe 4" for it to lay wet. This clear is quite runny, doesn't seem to be high solids, viscosity is similar to honey.

I read a lot about the hot air that the turbine produces. Not sure if it's the newer turbine design, but the air doesn't feel warm at all. Despite that, i did soak the hose in a tub of cold water.

I also tried thinning it from 20-50%. I could not get a nice finish no matter what settings i tried. Nice is subjective, i know, but what i'm getting now is worse than factory jobs. I played with the fluid output knob, when i turn it down i get almost no output. I turn it up and then i'll get orange peel. Can't seem to get the sweet spot.

Also, how fast are you guys moving your gun? Slower than conventional hvlp systems right?

How much orange peel is acceptable? I don't have any spraying experience before this, so i can't tell if the orange peel level is acceptable. I don't expect a glass finish off the gun, do plan on sanding.

Any tips or tricks you guys have would be appreciated! Especially modifications to the unit itself. Part of me regrets not getting the stage 3.. but i'm stuck with this now so...

Well, welcome and sorry you're having problems..... Oh, and I would imagine that Chris will probably bump this over to tools and equipment section. Okay, yeah, I don't particularly care for the 2 stage Fuji system. It's just underpowered for most auto paints. You don't have enough pressure coming into the gun cup to "push" the liquid at proper velocity into the air stream. Not sure what your acrylic product is but if it is an acrylic enamel they are quite problematic in that regard. Acrylic lacquer is a little better but is still trouble with this 2 stage. If this turbine is not feeling warm after about 5 minutes it may be one of the units that has Delrin or Nylon turbine wheels. These produce little to no heat so further soaking of the hose in ice or cold water would only make the performance WORSE than normal.
Let's try something to determine where you are at right now..... Take the gallon or quart can of your acrylic (no additives yet) and put a foot long stir stick into it all the way to the bottom. Quickly pull the stick up two inches above the liquid level and immediately time the number of seconds it takes for the liquid "stream" to change into "droplets". Most 2 stage turbine systems will need this to be 4 to 5 seconds at most. If this is more like 2 or 3 seconds the material is so thin that the volume of air is causing the liquid to dry (cotton candy) prematurely so it cannot flow out properly on the surface. In that case you would need a higher solids acrylic. If that number is more like 7 to 9 seconds you need more pressure/power to get proper atomization. And, no thinning will not overcome that big of a problem. The only thing you could try would be to run a separate low pressure (10 p.s.i. max., auto vacuum hose works fine) hose to the quart pot but this would be of only marginal help. In that case you are just "under turbined."
As you have already read, I generally like to see 3 to 4 stage systems for most automotive systems (yes, there are some larger 2 stage units but Fuji unfortunately isn't one of them). It's just like compressors, nobody has ever told me "My turbine is too big." You can choke a big turbine down, but it's difficult to near impossible to increase the performance of a small one.

Thanks for your input Darrel!

It's an acrylic lacquer

I did a http://www.youtube.com/watch?v=60DOhUEmcsM video in case i'm doing the test wrongly. I am getting about 15 seconds before it turns to droplets? Seems like it's not because it's too thin, but an atomization pressure?

Really hope to make it work with this setup now hmm.

So i called up the store to ask them what i could be doing wrong. He says it might be the thinner i'm using. I'm using cheap thinner bought from the normal hardware shop. Probably the reason why i'm not getting a nice flow out. Will be heading down to get the 2k thinner he said would be a good match with this 1k clear. Hope that works.

Well, I think you've found your problem. First, that's some thick lacquer. Yes, I got 12 to 15 seconds when I watched your video. It needs to be thinned down closer to the 5 second mark for your system. About 6 to 7 seconds might work but 5 would be better. Second, lacquer thinner formulations can be one of several hundred different formulas. Hardware thinners are just usually recycled "clean up" thinners that can have all kinds of simple sand filtered solvent contaminates in them. Bad stuff. You should always start with the matching thinner (slowest speed available for your lacquer) for your specific lacquer. Just keep the cheap hardware stuff for a gun cleaner.
When you get that correct thinner make a test batch with about 10% thinner to start with and try your stick test again. If you get in the 6 to 7 second range give it a go. If you can get decent flow out by holding the gun 4 to 6 inches from the surface and moving at about 3/4's the gun speed you see in most pro conventional gun videos you are good. Gun should be about 75 to 80 % open on the fluid and full air flow. With a 2 stage you'll have about a 6 to 8 inch wide fan at that 4 to 6 inch distance from your work. If it is still "dry spraying" or rough kick in another 3 to 5% thinner and try again. That should put you in the 5 second area. You might also see if your supplier carries a separate "retarder" for you lacquer. Minor (1 to 2 %) amounts can help flowout quite a bit with turbines.
Well, see if any of this helps.....

Thank you again Darrel! You've been a great help.

So i bought the quality, slow thinner. Thinned it by 20%, did the stick test and getting about 5 seconds. I'm not getting the dry spray anymore, the surface i'm spraying gets wet and smooth nicely. But now i'm getting another problem - dry overspray landing everywhere else. There is still some dry, white fuzz floating in the air. I take this as a sign that the clear is still evaporating off too quickly?

I was thinking of increasing the dilution factor even more, is that a bad idea? Or should i go straight for the stand-alone extra slow retarder? I'm sure my climate is the whole cause of this, i stay in a high humidity, high temp country.

Good, you are definitely going in the right direction. No, try not to thin it anymore. Now would be the time to try a good quality retarder. Retarders are also referred to as "flash off control solvents" in some geographic areas. Doesn't matter as long as it is compatible with your 1k lacquer and is designed to keep a longer "open time" on the coating. With your temp. and humidity there you still may not be able to eliminate it entirely, however, the neat thing about old style lacquers is they usually cut and buff nicely. That dry fuzz in the air is probably small particles breaking off your fluid nozzle tip as they dry too fast and build up. Retarder will also help keep that nozzle area "wetter," helping that situation.

Awesome, looking forward to tomorrow and hopefully i can get that retarder!

I read that keeping the hose relatively straight without excess coiling is good too, as it prevents excess pressure drop across the hose, especially important for a 2 stage turbine. So i'm going to try not-coiling the hose too much as well, hopefully i can get better atomization.

I was also thinking, the theoretical difference between this 2 stage (5 psi) and the 3 stage fuji (6.5 psi) isn't much. Hard to believe it makes that big of a difference in atomization, hmm. The 4 stage, on the other hand, is 9 psi so i can see how that makes a huge difference.

Am i right to say that the biggest problem with the 2 stage is this - adding enough thinner to allow proper atomization for a low stage turbine will affect the gloss level because there's not enough of the paint pigment, or whatever it's called, to provide good coverage?

Yeah, I'm hoping that will get it done, too.

Okay, yes, keeping the run of hose straighter does help but it has nothing to do with pressure, it has to do with CFM or volume of air.

Again your are not putting together the principles behind the operation of these guns. It is not about pressure, it is about CFM. A 3 stage will automatically deliver 33% more volume of air than the same 2 stage design. A 4 stage delivers a whopping 50% increase over a 2 stage. The operating pressure only helps somewhat based on pressurizing the cup itself so their is more "push" to heavier viscosity materials. In my opinion, a 4 stage is only needed with the heaviest of automotive urethanes. Acrylic lacquers like you are using will work fine with 2 and 3 stage turbines.

And, yes, that is mostly the problem. Excessive thinning is not allowing the pigments to lay down properly and cover. You end up hammering on a lot more coating on and not getting the right "look" for the coating. This is particularly true of special effect metallics, pearls, etc.