Mini Mite 4/Spraying issue

[Caleb Petke]

I have a fuji mini mite 4 spray system and I recently switched over to a new product to spray. I'm using the Emtech HSF5000 Primer and I am having issues with it coming out blotchy. I contacted the manufacturer and they had recommended spraying with a 2.0 tipset. I used it and had the same results of it being blotchy. I then thinned it to the settings to asks for and switched to a 1.8 tipset and am having the same issue.. Not sure what is causing the issue or what I should be doing to have a nice flow of paint coming out. Any help is greatly appreciated as I'm new to spraying.

[Jim Becker]

The ESF5000 product is a lot more viscous than many of the finishes, although EM6500 that often goes on top is certainly more viscous than the clears are, too. While I use a different kind of spray system than you have (an HPLV conversion gun with the PPS system) I find I need to kick the air pressure higher on my particular gun to get beyond the "spatter spray" issue with thick coatings. I don't know what options you have for that on a turbine system, but perhaps others may offer some help. You do need the larger N/N for these finishes, but have to have enough air to atomize it, too. One thing you do not want to do is thin any more than Target says is acceptable, but consider using extender for that rather than water which will help things lay out more before they start to dry.

[John TenEyck]

You have the wrong gun to spray that stuff w/o thinning - a lot. The viscosity is listed as 60 seconds Zahn #4. Compare that to their EM-6000 at 35 - 40 seconds through a Zahn #2 cup. That's about 10 seconds through the #4 cup. TC says to use 30 psi atomizing air pressure, which means pressure to the inlet of the gun. Your gun likely is limited to about 10 psi. It's all stacked against you with your spray equipment regardless of how big the N/N set you use.

You may be able to spray it if you can get the viscosity down to around 60 seconds Ford #4 cup, which is around 13 seconds through a Zahn #4 to give you a comparison to what it is in the can. I don't know how much water it would take to do that, but if it's less than 10% that would be the first thing I would try.

More bad news if you plan to spray EM-6500 as your topcoat, the viscosity of that is 40 seconds Zahn #3 (good grief, why do they keep changing cup size?) and that's something over 83 seconds with a Ford #4 cup, so you likely will have to thin that, too, though probably not nearly as much.

Turbine units are great for lower viscosity products but are challenged with spraying paint type products. An alternative primer you may want to consider is Zinnser Bulls-Eye 1-2-3 water based primer for all surfaces. It has an amazingly low viscosity and sprays great. At $30/gal at HD it's a true bargain.

John

[Prashun Patel]

That's interesting.
I sprayed these two products for a bathroom vanity. I also used a Fuji Minimite 4 with the stock tip (I think it's 1.3?)

I am using the PPS conversion cup, though. I am not sure that makes a difference. (It's a great investment btw).

I did not thin. IIRC I used grey. What tint are you using? This product did not feel nearly as viscous as a latex paint. It did not strike me as particularly viscous compared to the top coat tinted "lacquer". I didn't take great pains to get it to flow perfectly but it did. I also sprayed in the summer.

Is your issue environmental?

What do you mean by "blotchy"?

[Jim Becker]

Prashun, PPS absolutely makes a difference with higher viscosity finishes as it pushes them out under an even pressure/volume. That may be just enough to make the turbine system effective and give the results you report. I had trouble spraying these products with my old straight conversion gun (a Wagner), but with the PPS setup, no issue once I get it dialed in for the viscosity. But again, I'm not doing the turbine thing...

[John TenEyck]

Turbines supply the cup with the same pressure that goes to the gun. It doesn't matter if the cup is the stock one or a PPS HO retrofit.

John

[Jim Becker]

Turbines supply the cup with the same pressure that goes to the gun. It doesn't matter if the cup is the stock one or a PPS HO retrofit.

John

Interesting. I didn't know that there was no difference.

[John TenEyck]

Yes, that is interesting, Prashun. The PPS HO cup makes no difference over the stock turbine cup, as both have the same pressure from the blower. The viscosity of the ESF5000 is far lower than latex paint, which would be many multiples higher, but it's still 3 or 4X most clearcoats. It's really interesting you had no trouble spraying it. Higher temperature definitely should lower the viscosity and get it to flow more easily, but it's hard to imagine that could be the difference.

John

[Caleb Petke]

You have the wrong gun to spray that stuff w/o thinning - a lot. The viscosity is listed as 60 seconds Zahn #4. Compare that to their EM-6000 at 35 - 40 seconds through a Zahn #2 cup. That's about 10 seconds through the #4 cup. TC says to use 30 psi atomizing air pressure, which means pressure to the inlet of the gun. Your gun likely is limited to about 10 psi. It's all stacked against you with your spray equipment regardless of how big the N/N set you use.

You may be able to spray it if you can get the viscosity down to around 60 seconds Ford #4 cup, which is around 13 seconds through a Zahn #4 to give you a comparison to what it is in the can. I don't know how much water it would take to do that, but if it's less than 10% that would be the first thing I would try.

More bad news if you plan to spray EM-6500 as your topcoat, the viscosity of that is 40 seconds Zahn #3 (good grief, why do they keep changing cup size?) and that's something over 83 seconds with a Ford #4 cup, so you likely will have to thin that, too, though probably not nearly as much.

Turbine units are great for lower viscosity products but are challenged with spraying paint type products. An alternative primer you may want to consider is Zinnser Bulls-Eye 1-2-3 water based primer for all surfaces. It has an amazingly low viscosity and sprays great. At $30/gal at HD it's a true bargain.

John

I'm using the G-XPC Gravity gun that came with the system. I have thinned the product to 60seconds with the Ford #4 cup and get the same result. I'm not using it for a topcoat more for a primer/filler which was recommended for me to use. But I might try the Zinnser Bulls-Eye and see how that does with the system I have. Might just be the wrong product for my application/system or I'm not doing something correctly. I'm still somewhat new the finishing this way. Thanks for all the info.

[Prashun Patel]

What are you thinning with?

[Caleb Petke]

Distilled water.

[John TenEyck]

I'm using the G-XPC Gravity gun that came with the system. I have thinned the product to 60seconds with the Ford #4 cup and get the same result. I'm not using it for a topcoat more for a primer/filler which was recommended for me to use. But I might try the Zinnser Bulls-Eye and see how that does with the system I have. Might just be the wrong product for my application/system or I'm not doing something correctly. I'm still somewhat new the finishing this way. Thanks for all the info.

Fuji literature is strange. It's a pressurized gravity cup. ???

In any case, it's pressurized, assuming you have the air tube connected? Also, there probably is a check valve in that air tube. If so, make sure it's operating. Disconnect it from the cup. You should be able to feel pressurized air coming through it when the trigger is pulled. If you can't the check valve is stuck.

John


9600 G-XPC™ GRAVITY SPRAY GUN




Featured with a side-mounted pressurized 400cc gravity cup with stand and a with a swivel and set feature. The G-XPC easily allows the operator to spray in any direction, making it perfect for bathtub and countertop refinishing, cabinet casework, and elaborate bespoke furniture. With the G-XPC you have a full range of spraying right at your fingertips!
Some of the most sought after features of this spray gun is the exclusive side-mounted Fan Pattern Control™ to adjust the fan size, and the swivel and set cup. The G-XPC gravity spray gun is non-bleed, meaning that air passes through the spray gun only when the trigger is pulled, resulting in less turbulence in the spray area, less paint buildup on the tip of the fluid nozzle, and far less spray gun noise. All newer Fuji Spray® turbines are designed and built with a bleed-off inside the turbine to allow the use of any non-bleed spray gun.

The G-XPC™ Spray Gun Series Difference:

• 1.4mm air cap set installed
• 9600-G-XPC™ spray gun optional nylon cups available in 3oz, 400cc, and 600cc
• Non-Bleed spray gun leads to less blowing around of shop dust and negligible turbulence in the spray area
• Side-Mounted Fan Pattern Control – Adjustable incremental fan pattern with three orientations: horizontal, vertical, circle
• Stay Cool Handle™ nylon-coated handle always stays and provides a comfortable grip
• Rotating nipple assembly – makes for easy adjustment of the pressure tube, especially for those who are left-handed

[andrew whicker]

Is there a way to get something pressurized in the system by an air compressor?

Like a 3rd person vendor that supplies something with an air hose connection that still works with the hvlp turbine guns?

Edit:

On my fuji 2 qt pressure pot it uses a 1/4" nps thread. So I guess I could convert that to a compressor female? Maybe that would help us turbine people? Or is this a bad idea?

https://www.harborfreight.com/14-in-...er-63549.html?

[andrew whicker]

Maybe the higher temp gave the coating more time to self level?

Did it look orange peel and then self level?

[John TenEyck]

Andrew, the cup/pot on your turbine unit IS pressurized, at the same pressure going to the air cap, typically around 8 psi. 2 stage units likely are a little lower and 4 stage units a little higher. My HVLP conversion gun has a pressure assisted cup, too, the pressure to which I can control up to the max. blow off pressure of around 9 psi, IIRC. I've never found a need to use more than about 6 psi, even when spraying products like the OP is using. The more important issue is sourcing products that are compatible with your spray equipment. Thinning is sometimes required, but it's better to choose products that work with the equipment you have w/o resorting to that.

But to answer your question, yes, you can convert a gravity feed gun to a pressure feed one by changing to a pressurized cup and running a line to it from a compressor, with a low pressure regulator to control the pressure in the cup. Some years ago, someone here posted a gun that had been converted. It's as simple as I described. The very low cost HF purple gun would make an excellent candidate for such a conversion.

John