Going insane trying to spray GF HP Poly & GF Enduro Clear Poly...

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Forum topic by DustinB posted 05-23-2015 02:50 AM 4115 views 0 times favorited 19 replies Add to Favorites Watch
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2 posts in 520 days

05-23-2015 02:50 AM

Hey guys, I’m about at my whits end trying to spray this stuff. I don’t know what else to try. I’ve talked to general finishes and fuji as well as many hours of reading everything I could find on the net from forum threads to articles to manufacturer’s guides. So many conflicting causes and solutions, yet I’m unable to get a smooth finish. There’s no way this can possibly be so hard.

I’m spraying with a new Fuji Q3 turbine setup with the T75G gun and the 3M PPS cups. Using the 1.3mm nozzle(the cup is pressurized). GF and Fuji both confirmed that is the proper nozzle, though I do have the 1.0mm set I haven’t tried. Doing this in my climate controlled shop, 75 degrees and 46% humidity.

This all started when I was doing my first spraying with general finishes high performance poly. I was always getting orange peel, and sometimes I would get air bubbles if the finish was laid on too thick.

I decided to get a can of the enduro clear poly and try that instead. Now I’m getting orange peel and bubbles no matter what the thickness is. I’m using plywood and the board I was spraying the gf high performance on after sanding perfectly smooth. I’ve wiped it clean with a dry cotton cloth and I’ve also tried wiping it with a 50/50 mix of DNA and water.

I’ve tried spraying very thin coats, medium coats, thick coats. Checked with a wet film gauge and I’ve read 1 thru 5 mil in my different tests, GF advises 3-5mil. I’ve adjusted the air up and down(hose is straight as possible). I’ve adjusted the fluid more and less. I’m sure I’m getting a very fine atomization. I’ve gotten close to the work, further away from the work, smaller fan width, larger fan width. Goes on as a finely atomized mist. Tried it where it slowly starts to flow out all the way to where it quickly flows into glass. After several hours and even days later the orange peel is still present.

I also just tried spraying glass with the GF Enduro Clear Poly and I get orange peel and bubbles.

The GF HP viscosity measures 20 seconds through the fuji cup(said to be a ford #4) which is strange because they advertise 35-45 seconds. The can has a date of 8/28/14.
The GF Enduro Clear Poly measures 23 seconds, which is also weird because they advertise 40-50 seconds. The can has a date of 3/2/15.

Both cans are unthinned. I find it strange to think they could both be bad cans being so recent and from 2 different unaffiliated local stores. I did try thinning the GF HP by about 10% with the extender which didn’t help.

Not using stearated sandpaper, everything cleaned with denatured alcohol or RODI water. Tried on glass, plywood, poplar, walnut, with and without zinnser sealcoat. The guy at Fuji says with my setup and water based finish, the only possible cause is too thick of a coat, yet I have tried coats so thin the mil gauge doesn’t register all the way up to about 6 mil.

I’m am absolutely lost and extremely frustrated with this. Never in my entire life with all the things I have done, have I EVER had even a fraction of the difficulty I’m having with this. If anyone can share some insight, things to try, solutions, I would be eternally grateful.

19 replies so far

View MrUnix's profile (online now)


4028 posts in 1619 days

#1 posted 05-23-2015 03:10 AM

Orange peel can be caused by many factors, but the most common is trying to spray material that is too thick. I don’t have a turbine, but I frequently spray poly (oil based) with a gravity feed HVLP gun, and I thin it pretty heavily – way more than what is recommended actually. It results in a great finish, but requires more coats.

Somewhere I read, and it seems to hold true, that the poly doesn’t care how it gets there, just that it gets there. That is the key to doing wipe on stuff where it’s mixed at about 50/50 with mineral spirits. It takes a lot more coats to build up the same thickness you would get by brushing, but in the end, they produce the same results (although the wipe on never has brush strokes :)

As always, YMMV.


-- Brad in FL - To be old and wise, you must first be young and stupid

View pintodeluxe's profile


4825 posts in 2233 days

#2 posted 05-23-2015 03:35 AM

Couple things.
1. Eliminate the cleaning with water or denatured alcohol step. To prep the surface for a topcoat, just wipe it down with cheesecloth (not tack cloth), and blow it clean with compressed air.
2. Thin your poly with the recommended thinner (usually mineral spirits). Thin 20% to start.
3. Stir your poly well, but don’t have it shaken.
4. If all else fails, switch to lacquer which is much easier to spray. I use Rudd Dura-Cat and spray with a gravity feed HVLP conversion gun. I prefer lacquer because the second coat blends in well with the first. Also lacquer dries very quickly, which is nice because you can spray two coats in a day. Poly can be slower to dry, although it has sprayed well for me in the past.

Good luck, let us know how it goes.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Shadowrider's profile


183 posts in 629 days

#3 posted 05-23-2015 06:09 AM

I’ve seen these posts before and I am really thinking that it’s got to be something about the turbine system because it always seem woodworkers use turbine setups. I’ve never used a turbine system but I’ve used about every other system out there and sprayed a bunch of waterborne epoxies, 2K basecoat/clearcoats, just about everything you could ever put on a car or airplane, not to mention plain oil based and lacquers. Every time excessive orange peel was caused by the material having too much viscosity for the temp or conditions I was spraying in.

I can say that I’ve been brushing on (foam brush) Enduro-Var and I’ve never seen a finish of any kind that “lays down” as smooth as this stuff. I was very skeptical of it at first because it is pretty dang thick, but dang if it doesn’t work flawlessly every single time. I mean it’s hard to get it to mess up. Thick coat, thin coat, it’s all good. It’s not the same product as you are using, but have you tried a test by just using a foam brush? Might be worth a shot to see if the product is bad. If it looks good with that it’s likely not bad.

I wish you luck and am really curious to see a resolution because I’d like to spray this stuff at some point as it will save a bunch of time.

View jtm's profile


217 posts in 1056 days

#4 posted 05-23-2015 07:13 AM

I have the Harbor Freight/Rockler super cheap HVLP turbine sprayer.

I can spray GF High Performance Poly straight out of the can all day long and get a perfect finish.

On the other hand, Enduro gives me a lot of problems with orange peel.

So now I only use High Performance.

View Fred Hargis's profile

Fred Hargis

3841 posts in 1913 days

#5 posted 05-23-2015 11:30 AM

Man, your experience with HP doesn’t jive at all with mine. I used it on some medicine chests earlier this year. Sprayed with a Fuji Q4, and the XPC gravity gun. Out of the can, the HP was 70 seconds through the #4 cup. I thinned it 20% water (max allowed, IIRC) and it got down to about 25 seconds (all this from my project notes). I then sprayed it with a 1.0 mm tip set and it lay down quite smoothly. The first raised the grain, I sanded it smooth and put on 2 more….done. I would try thinning it as much as 20% and give it a try, Brad called it…almost all orange peel problems start with a finish that’s too thick, it can’t level out.

-- Our village hasn't lost it's idiot, he was elected to congress.

View CharlesNeil's profile


1602 posts in 3290 days

#6 posted 05-23-2015 12:54 PM

you need to reduce the fluid, you want a slight texture about like a 120 or 180 grit sand paper and you want to see a bluish haze , this lets you know your wet enough. You can thin, 20% may be a bit much in my opinion, usually 10 % is enough. Just reduce the fluid, the issue is you have more fluid coming out than the gun can atomize, note the texture on the glass In this video I did

View ScottM1's profile


122 posts in 1002 days

#7 posted 05-23-2015 01:25 PM

I have to agree with Shadowrider. When I first started using conversion varnish I was using a turbine system. The Tec that was demoing their product strongly advised us to switch to a compressed air system. He stated that conversion varnishes as well as other types of finishes do not like the hot air that the turbines generated. I continued to use my turbine for the rest of the winter. When summer came around the resulting finishes declined dramatically. Orange peel, solvent pops etc. We switched to compressed air. All is good now.

-- Scott Marshburn,, FaceBook,, Twitter,

View DustinB's profile


2 posts in 520 days

#8 posted 05-23-2015 05:12 PM

Thanks for the replies guys.

Here’s my latest test. This was with the enduro clear poly thinning about 10% with the enduro extender. I also dialed down the airflow by about 40%, needle is about 3/4 of a turn out, moving about 6”/sec at 6” away. I did what the fuji tech said and sprayed a very light coat and 5 minutes later did a thin coat at about 4 mil. Seems to have leveled out much better, you can only see the orange peel around bright reflections but it’s very light. I’m guessing I need to thin it down a little more, but I still get the air bubble marks. It looks like they develop shortly after spraying but not during. I’m guessing it may not necessarily be that the material is too thick to level out, maybe it’s drying to fast with the dry air in my shop?

Still doesn’t explain the problems I had testing the hp poly, I tested everything including thinning. Always ended up with worse orange peel or air bubbles, wth the enduro clear poly both at the same time. I don’t know how so many people have no issues at all, thick or thin coats. Maybe I’ll try some more samples and take some pics as I’m doing it, maybe someone can see what I’m doing wrong.

Charles, if I reduce the fluid flow any more I will start to get dry spray. If I spray like in these pics, very similar to what you describe, I get slight orange peel in the reflections but I also have bubble craters. The spray coming out of the gun is a very fine mist like in your video, but less volume.

I don’t know why these pics show so much texture, it’s not exactly what it looks like to my eye. You can see the film thickness in the first pic. 2nd and 3rd you can see the air bubble craters. The last one you can see the orange peel pretty well in the light reflections.

View stillgotallmydigits's profile


34 posts in 898 days

#9 posted 05-24-2015 06:42 PM

Interesting thread. I have been using an Earlex5500 and the GF hiperf poly with the same results you are mentioning. I switched to a 1.4 needle from my 1.0 and things improved as the orange peel has almost disappeared. BUT… I had to go painfully slow laying down a blue strip only 5-6” from the surface which resulted in about a 4” wide strip each pass. I overlapped at least 50% and it looked like everything flowed together well but as the finish dried you can see stripes between each pass…arrgh. I have ordered a Fuji Q3 and am eager to try it as I think it can lay down finish much faster than the Earlex. I hope anyway, as much of our work involves fairly large surface area, and at the speed we have to go with the Earlex, finishing time is eating away at our profit! We also purchased some Sherwin Williams “Gemini” clear but have not tried it yet. Anyone out there have experience with that product?

-- Steve, So.Cal.

View jak77's profile


18 posts in 1361 days

#10 posted 05-26-2015 12:25 AM

You will never get a smooth finish with a turbine. The cup is pressurized because there isn’t enough air generated to atomize the coating and pull it out of the gun. All these HVLP systems were developed to increase transfer efficiency to placate the EPA. Not because they provide the best finish. Turbine systems are used because most people don’t have enough air to use conventional spray systems. Please realize that in the real spray gun business the latest HVLP guns which are the absolute best go for around $700. That is just the gun.

If you want a smooth finish out of the gun. More air and less fluid. You can get less fluid by switching to the 1.0 nozzle. But you cannot get more air.

Switch to the 1.0 and thin your coating. Thin coats will dry faster allowing you to sand between coats to build a flatter finish.
You are trying to coat a porous, profiled substrate and achieve a flat finish out of the gun. This can only be accomplished with multiple coats and lots of sanding.
And remember every coating can perform differently on any given day. You will find one works great one day and not so well the next. Finishes are developed to work under most conditions. None work under all. Find one that generally satisfies you and adjust as you go.
Spraying glass will never give you a true representation of performance. It is too smooth with no profile for the coating to fall into. Only use glass to judge the droplet size at the edge of the pattern or the shape of your guns spray pattern. You do not want super fine ‘dry’ spray at the edge of the pattern.
Sorry to say there is no magic. Been using and selling spray equipment for almost 40 years. Adjust your expectations. And think “Thin to win”

View BroncoBrian's profile


435 posts in 1378 days

#11 posted 05-26-2015 03:47 AM

Didn’t know these were both available Gluten Free.

-- Bigfoot tries to take pictures of me

View pintodeluxe's profile


4825 posts in 2233 days

#12 posted 05-26-2015 04:39 AM

Here is another test. Go to Harbor Freight and buy their $15 gravity feed gun. If that lays down a smooth finish, then your sprayer at fault.
It may help you determine weather the sprayer or the finish is causing the problems.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View MrUnix's profile (online now)


4028 posts in 1619 days

#13 posted 05-26-2015 04:49 AM

Go to Harbor Freight and buy their $15 gravity feed gun.

They are on sale now (until 5-31-2015) for $9.99 with coupon code 85416273

A paper coupon was in this months flyer as well… code 91121577 in case you don’t have one. Or you can print one out here:

Great guns and well worth the $10 :)


-- Brad in FL - To be old and wise, you must first be young and stupid

View stillgotallmydigits's profile


34 posts in 898 days

#14 posted 06-10-2015 03:44 AM

A happy update to my previous comment with some polite disagreement with Jak who has much more experience than I. I have just completed my first project with my new FujiQ3 gold and I could not be more pleased with the results. I used the Gemini water-clear lacquer and the finish is flawless! No more orange-peel for me! The extra “wind” from the 3stage turbine in combination with the huge fan width had me choking things down a bit when spraying smaller panels. Now I can concentrate on areas where I completely agree with Jak; everything depends on the weather! I can’t get conversion varnish here in So.Kalif. so I have to stay with the lacquer and learn how to make adjustments to avoid the dreaded blushing. We’ll get there though so for the time being it looks like the ol’Earlex for spraying stain and paint and the Fuji for the finish work. Oh, one nit-pick on the Fuji…it sure is hard to get that top mounted gun into tight areas! Might have to invest in some smaller cups/side mount/pressure fed???

-- Steve, So.Cal.

View Renron's profile


3 posts in 1894 days

#15 posted 02-14-2016 08:58 PM

“You will never get a smooth finish with a turbine.”. I respectfully say B.S. to this general statement. I have been spraying HVLP Turbines for almost as long as you have been selling them. I used to refinish Antique Clawfoot Bathtubs and when I completed the job it looked just as good as a porcelain tub. Which is to say, BETTER than an enamel steel tub.
I did not polish them either. I did not sand them, perfect finish off the Siphon feed gun.
However, I must say that the product I was spraying was >$300 / gallon. Epoxy primer was even more $$$.

I do agree with Jak77 about everything else he said in his above post. Turbines produce HOT air which can dry the exterior of the droplets before they hit the surface of the sprayed object, this will cause orange peel texture. Having the HOT air blowing on the surface of the newly applied top coat will exacerbate the issue, and potentially cause cratering or solvent pop looking structures on the surface. The air gets hotter the longer the turbine runs and shorter hoses do not allow sufficient time to cool the blown air.
The first picture above is an excellent example of dried droplets. HVLP Turbine guns should be no more than 6 inches MAX from the target, unless you are trying for a texture. This is one way to make the final top coat of a gloss product look like a semi-gloss or even satin finish.
Quite often even a slight breeze over fresh water base finish is enough to “skin” the top and prevent self leveling, causing orange peel. I have found humidity to be a real bear of an issue too.
Try different products in your turbine setups, they will respond differently to the Hot air.

showing 1 through 15 of 19 replies

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