Spraying Enduro Var II

[Bill McNiel]

Help me please, I am attempting to spray a coffee table top (3' x 6') with Enduro Var II Satin using a Fugi 4 stage and am getting really small (less than 1/36" diameter) but totally aggravating volcano type random peaks.

Finishing Room temp 70 degrees
No dust
Relative humidity = 35%
Fugi 4 stage Platinum - 1.0 tip & 1.3 same problem
Viscosity = 16 seconds

I have shot a ridiculous number of test panels varying the fluid amount from the gun without consistent success.

I have also tried 3mil thickness down to relatively light (think almost leather)

I just bought some GF Extender but have not yet tried it.

Any suggestions, words of wisdom, etc?

[Prashun Patel]

Please post pictures.

[Bill McNiel]

I Phone quality photos

[Paul F Franklin]

Are you straining the finish before spraying?

[Bill McNiel]

Are you straining the finish before spraying?

Yes, both from the can and from the cup (T70 has a strainer). I really don't believe it is dust, Finishing Room is really clean and it appears to be a fluid issue.

[John TenEyck]

Looks like particles to me. Is your gun clean? If you are sure it's not particles then I would guess it's because the RH is low. Combine that with the hot air your turbine produces, and it can cause droplets to dry prematurely and create particles that won't flow out. The solution is to use a larger orifice (the 1.3 should be OK, but try a 1.5 if you have it) and add Extender, either alone or in combination. You might try thinning it, too, if you still have the issue.

What units is your 16 second viscosity? Can't be the common Ford #4 cup.

John

[Bill McNiel]

John - thanks for replying,

Yes, as far as I can tell it is a Ford #4 cup that was provided by Fugi at the time of purchase. I just ran another five time trials and they all came in at 16 to 17 seconds.

GF recommends either 1.1 or 1.3 mm and I have tried both with the 1.1 getting marginally better results. I do have 1.5 & 1.8 so I can give the 1.5 a try.

My perception is that the low humidity is adversely affecting atomization.

Would you recommend more or less fluid, as in 3mm lay down or multiple lighter coats?

Extender or water?

Again, mahalo

[John TenEyck]

Bill, it can't be a #4 Ford cup. The original EnduroVar was around 50 seconds. EnduroVar II is listed as 200 - 300 cps which would be 58 - 74 seconds through a #4 Ford cup. Looking on the same chart, I see that a Zahn #4 cup would give a time of 17 - 24 seconds for that viscosity range, so that's probably the cup you have. OK, your EnduroVar looks like it's in the normal range.

Low RH doesn't cause atomization problems. What it causes is the atomized particles to dry faster. So does the hot air from your gun, which is one of the advantages of a conversion gun run from a compressor. So, as I mentioned before, the way to overcome that problem is to use a large orifice so the particles are larger, move your gun closer to the work so the particles don't dry before hitting the surface, and/or add Extender. Heavier coats, 3 to 5 mils can help give more time for flow out, but at the risk of orange peel. No free lunches with finishing. GF says to use Extender in warm or dry conditions, which is what you have: https://generalfinishes.com/sites/default/files/documents/files/2021-01/TDS-2020-11-Enduro-Var-Il-General-Finishes.pdf

I would try the 1.3 or 1.5 mm orifice with 4 to 6% Extender, and move your gun closer to the work. Try to get an 8" fan when 8 - 10" off the work. Adjust the fluid flow so that you get a good, wet coat (around 3 mils) when your passes overlap by half.

John

[Bill McNiel]

John,

Again, I thank you for sharing your knowledge and providing me with some clarity on the cause and future course of action. Your assistance continues to be invaluable and is needed and appreciated.

I never thought to question if I had a Ford #4 or why Fugi would depart from such a universally accepted standard. Or maybe, and quite possibly the case, it is my restricted knowledge of finishes.

I plan on trying out your suggestions tomorrow.

Mahalo - Bill

[John TenEyck]

Bill, did you ever overcome the bubbles with EV II? I'm having the same problem when brushing it. I haven't tried spraying it yet, but after finding this thread I'm not too optimistic it will be much better.

John

[Tom M King]

I feel like I should chip in for the cost you have in the finish you two have convinced me to stay away from. Many thanks!