Spraying Enduro clear poly

[Andrew Goraj]

This is an edit and update to spare people from reading The entire thread. It's filled with valuable insite and worth a read. But for my specific issue, it Turns out my hose connection to my turbine was loose!

Hey everybody! So, I'm having a whole lot of trouble spraying GF enduro clear poly, and was wondering if some of the experts on here could advise.

What I have : Fuji mini mite 5 stage with needles 1.0 , 1.3 and 1.8. I'm measuring 24 seconds for the enduro clear poly out of my ford cup that was included with my sprayer (#4)? Which leads me to use the enduro unthinned with a 1.3 needle.

Project specs. Spraying 8 foot tables. Prep was sanding to 180 grit followed by water carried transtint dye sprayed with my hvlp.

Secific question is, am I supposed to see a blue haze with this stuff? Or am I spraying it too thick? I have 3 options and none seem quite right

1) I spray it so that there is no blue haze, it feels like it's going on so light that it's getting gritty? I can see individual droplets and they don't seem to flow out or coalesce. .
2) I spray with a medium build, my overlapping areas have this blue haze, and inbetween the overlapping runs is clear. This essentially Leaves stripes of blue.
3) I spray it thick, everything goes blue, but it just takes long to dry and feels wrong. Also, it's lifting water based dyes and ruining The dye job.

Any help?! Should I switch to the high performance? Or can you teach an amateur hvlp'r?

[Patrick Chase]

I have a Q5 (basically the same turbine) and I have some Enduro clear poly that I recently ordered to try, but I haven't done so yet. I'll update this thread when I do. Your viscosity # and needle selection are consistent with General's recommendation for that finish.

Offhand it sounds like you're either not overlapping enough or are overlapping too much, and are spraying a nonuniform coat as a result. The usual advice is to overlap by 50%, i.e. half of the fan width, such that the center of each pass lines up with the top edge of the previous one and the bottom edge of the next (assuming you're working away from yourself). If you overlap less than that then the previous and next coats don't "meet" and the center of each pass only gets one coat, leading to banding. Similarly, if you overlap too much then the previous and next coats overlap such that the center gets 3 coats, with similar results.

What you describe could also happen if the fan pattern knob is misadjusted such that you're spraying a "center-heavy" or "edge-heavy" pattern. Did you shoot test patterns on cardboard or paper and confirm that you're getting reasonably uniform density across the fan?

A wet mil gauge (which should have come with your HVLP IIRC) is your friend here. Have you checked thickness in the dark and light parts of the surface?

[Jamie Buxton]

One more thing to check. Do you have the spray cap oriented so that the spray fan is across the direction you're moving the gun? Or is it parallel to the gun movement?

[Andrew Goraj]

Thanks for the reply. Yes, please update when you do try it.

I did a lot more testing last night.
Seems I have two options. The first is a light coat, there is no blue haze created, but the droplets land and interlock, almost like a checker board, and dry that way. Has the appearance of orange peel, but I don't believe it is. Kind of looks like individual drops of rain on a windshield, joining together but not flowing out. Hard to even measure this with a wet mil gauge.

Second option results in a deep blue haze, completely opaque. I cannot see the wood through this haze. The material flows out a little better. Eventually this blue haze subsides and dries clear. I have slight orange peel. General finishes says I should NOT see any of this blue or opaque haze, and if i do, I'm applying it too thick.

If I spray it thin enough to erradicate the blueish haze, it seems too thin, droplets too large and drying without flowing out.

I just really am uncertain if I'm supposed to see this deep blue haze or not. I never know who I'm talking to from tech support, and if they are just reading from a sheet.

I've had the Fan pattern knob adjusted correctly. GF recommends 6-8" fan 6-8" distance, which is what I "was" doing. But I talked to their support line, they said to open the fan all the way up however. This results in a fan of like 18"?!

Maybe I should try and thin 15% and stick with the 1.3. Or step up to the 1.8. I don't have a 1.5 unfortunately.


I agree with the overlap 50% comment. I realize my problem is, my first pass should be "hanging" 50% off the project and 50% on the project. I was starting my first pass completely in the field, and overlapping that by 50%. This left the leading edge periphery too light. And threw off my pattern for the rest of it. So this I remedied last night.

I'm perplexed. I sprayed my entire set of kitchen Cabs with BM advance and they are factory looking. And this system isn't even designed for that. From primers to dyes to latex, no problems.

[Chuck Saunders]

I use Enduro and I love it. I don't quite understand, if you get a blue haze wen you spray but it dries clear then you're doing it right. The blue is an indication that you have laid down a good coat. If you are getting a blue haze when it dries then I don't know. Too light a coat and it won't flow out. Enduro should be ready to recoat in 45 minutes.

Since you are laying a water based finish over water based dye I'm not surprised that the dye is dissolving. You should probably lay a seal coat of a non water based finish to act as a barrier coat between the two.
Chuck

[Andrew Goraj]

For the people who Enduro sprays well for.

1) Are you talking about a completely opaque blue when you first lay it down, or is there some clarity through it?
2) What system are you spraying with and what needle size?
3) Do you thin it?
4) What fan width and distance do you hold the gun from the project?

My major issue is I had some orange peel at first. General Finishes support told me if I get a blue haze, I'm laying it on too thick, which creates the orange peel. So I've been trying to lay it on thinner to avoid this blue haze. But I can't figure out how. So this is good to hear.

In regards to seal coat. I used transtint Dye dissolved in water. But the dye dissolves in alcohol and water. Would it make a difference if I spray a light coat of Enduro, versus a coat of Dewaxed shellac (Since transtint can re-dissolve in both)?. My problem when the dye redissolved was I layed an extremely heavy first coat.

[John TenEyck]

I sent you a PM, but I'll add a few comments here for others' benefit.

You don't want blue haze. You want to spray 3 or 4 wet mils. I suspect the problem you are having when trying to spray lighter coats is due to a combination of your turbine gun and the hot air it makes and the RH where you live. The solution is to add Extender and/or water, preferably Extender.

I would not go to a larger N/N; actually, I'd go with a 1.0 or 1.1 mm if you have it. I use a 1.0 with my pressure assisted gun, and your turbine gun's cup is pressurized. The viscosity of Clear Poly is around 45 seconds #4 Ford cup (not sure how you got 25 unless it's really warm, still seems too low). Anyway, stay with your 1.3 mm, or go smaller, and add Extender.

If you spray 3 - 4 wet mils and there's enough Extender in it it will flow out without lifting your dye (unless maybe you sprayed multiple coats of dye) and w/o forming orange peel.

FWIW, Clear Poly is nothing like BM Advance. Advance takes hours to set up at 50% RH, Clear Poly takes minutes. But it takes longer than seconds, which sounds like your problem, so add Extender. I don't need it with Clear Poly, but for the products I do use it with I use 3%. You may need more. Try it with some scrap and go from there.

Your spray gun doesn't sound like it's set up optimally either, as Patrick addressed. You need to spend some time getting a nice uniform pattern, regardless of what the fan width ends up.

John

[Andrew Goraj]

Thanks for the reply John and the PM. I really appreciate it. I'm going to respond here only, so others can follow if need be some day.

I am very surprised I have half the time through my #4 cup as you. I just double checked the spray gun from Fuji, and it did indeed come with a #4. How can we be this far apart? I ran it through the cup many, many times to be certain over the course of multiple days

Everything you say about the NN size and extender makes sense in my head. I'm just surprised that I would need a 1.0, since Fuji recommends a 1.0 for 8 seconds or less through the #4 Ford cup.

The strange thing is I live in Upstate NY. It's only been 65 degrees and approx 70% RH when spraying. Would you still recommend the extender given this location information?

[Patrick Chase]

I did a lot more testing last night.
Seems I have two options. The first is a light coat, there is no blue haze created, but the droplets land and interlock, almost like a checker board, and dry that way. Has the appearance of orange peel, but I don't believe it is. Kind of looks like individual drops of rain on a windshield, joining together but not flowing out. Hard to even measure this with a wet mil gauge.

Second option results in a deep blue haze, completely opaque. I cannot see the wood through this haze. The material flows out a little better. Eventually this blue haze subsides and dries clear. I have slight orange peel. General finishes says I should NOT see any of this blue or opaque haze, and if i do, I'm applying it too thick.

John probably covered this in his PM, but it sounds like the finish isn't atomizing properly in the gun, such that you're shooting large droplets instead of a finer spray. Try closing the needle down and/or increasing the air. Also check and make sure that your hoses aren't kinked or constricted somewhere such that the turbine is spilling air through its relief valve. Your MM5 is plenty powerful for this (and then some) provided all of the air reaches the nozzle.

[Patrick Chase]

I am very surprised I have half the time through my #4 cup as you. I just double checked the spray gun from Fuji, and it did indeed come with a #4. How can we be this far apart? I ran it through the cup many, many times to be certain over the course of multiple days

You may have a bad batch of finish, for example one that was mixed incorrectly at the factory or went through one or two freeze-thaw cycles too many. That would be consistent with both the bogus viscosity measurement and the difficulty getting it to atomize properly.

[Andrew Goraj]

Gotcha. It definitely seems like you guys are hitting the nail on the head. The droplets do seem too large. I'm just surprised that a 1.0 needle would be necessary when using Fuji's reference sheet for NN selection based on viscosity I'm going to give the 1.0 a try. Patrick, when you give it a try, please let me know what you did and if it worked.

Not to get off topic, but have you ever used a foam brush to apply Arm-r-seal over a heavy, water carried, transtint dye job? I think i want to finish my current table with Arm-r-seal so I can get this table finished, before resuming my experimenting with the Enduro. Just nervous the Arm-r-seal will pull the Dye if brushed on.

[Prashun Patel]

I spray a fair amount of Enduro Clear Poly with fairly unsophisticated equipment. I have found it to be very forgiving.

"1) Are you talking about a completely opaque blue when you first lay it down, or is there some clarity through it? "
- No. Sometimes when I lay it a little thick, it does have a blue haze. These coats take a good deal of time to dry, but ultimately lay out reasonably fine. But the longer dry time just leads to other problems, like allowing dust to settle in the finish. If I spray it too thin, it can feel gritty; almost like a formica surface. The optimal film for me is fully wet, but still clear and only slightly blue.

"2) What system are you spraying with and what needle size?"
- I use a Fuji Semipro 2, 1.3mm (standard) air cap set. I have also used a $100 Rockler HVLP unit with perfect results.


"3) Do you thin it?"
- No. I do strain it through a paint strainer. I also get better results spraying without the little pre-filter basket on the uptake tube in the gun.

4) What fan width and distance do you hold the gun from the project?
- 9-12 inches. Always spraying in the vertical or horizontal pattern; never concentrated. I have sprayed single, double, and triple coats immediately, taking care to stagger overlaps and rotate. But it really has not made a difference; it's always pretty good.

"My major issue is I had some orange peel at first. General Finishes support told me if I get a blue haze, I'm laying it on too thick, which creates the orange peel. So I've been trying to lay it on thinner to avoid this blue haze. But I can't figure out how. So this is good to hear. "

- I agree it sounds like you're too thick. I am unsure what you mean by "I can't figure out how". Just dial back the amount of fluid coming out of the gun. I would say I'm about 5-10% open.

"In regards to seal coat. I used transtint Dye dissolved in water. But the dye dissolves in alcohol and water. Would it make a difference if I spray a light coat of Enduro, versus a coat of Dewaxed shellac (Since transtint can re-dissolve in both)?. My problem when the dye redissolved was I layed an extremely heavy first coat."

- No it won't make a diff. I frequently dye and then topcoat as you have done. A thinner coat that dries quicker will eliminate bleeding of the dye. I've sealed with shellac and Clear Poly and it makes no difference to the performance of the dye. Spraying shellac under Enduro Clear Poly is IMHO an aesthetic choice. You might try dissolving your transtint dye in ethanol and spraying that. I get better control of depth and consistency this way.

[Andrew Goraj]

Man, Thanks a lot! Really appreciate these replies. You guys are great. I spend so much time reading and not asking, it's very cool to have specific questions answered. When I said "I can't figure out how," I was speaking in regards to dialing back so there was no blue, but then getting a wet coat still. When I dial back so there isn't any blue, I get large dried droplets that don't coalesce. Maybe I did get a bad batch? I mean,I'm not kidding myself. 99% chance it's user error. But I'm not a dummy either, so not sure what the heck is going on. I just got another gallon of it. I'm going to time this one through the Ford cup when I get home.

Prashun, have you ever wiped on Arm-R-Seal over a heavy water carried transtint dye job? If so, did it lift the dye bad?

[Prashun Patel]

Dumb question: are you dialing back the air or the fluid? I dial back the gun/fluid, but keep the air "mostly" open; about 75%. My equipment doesn't show the air pressure or volume, so sorry I can't be more helpful than that.

[Andrew Goraj]

Definitely dialing back the fluid. But it doesn't hurt to ask! I can dial back the fluid no problem, just getting sprayed droplets that aren't flowing when I dial it back. I have to find a happy medium. I'm going to go home and experiment a bit with the new gallon I just got.