# Stopping HVLP Splatter



## Nate1 (Aug 21, 2013)

I am having splatter issues with a my new Astro Pneumatic EuroPro HVLP gun and am looking for advice.

When spraying Emtech (Water based pigmented "lacquer") I am getting what appears to be decent atomization, but every 1'-2' I get a couple small splats of material. It is very consistent in that it does happen enough that I could not apply a final coat of material if I wanted to.

I have done some thinning of the material per the manufacture's instructions of starting at 5% and it helped somewhat. But it did not completely solve the problem. I want to be careful how much water I am adding to the product as I am spraying on wood and do not want to increase and potential to raise grain.

On top of this the manufacture tells me I should be able to shoot the product right out of the can without thinning as the product was designed for HVLP use.

Having spent my day yesterday testing psi, adding/removing things to impact CFM (including a different smaller compressor to try to increase the splatter problem), thinning, adjusting fan, adjusting material delivery, and changing tip/cap size (1.9mm and 1.3mm)....I am out of ideas of what I could be doing wrong.

Recommendations?

Gun: http://www.astrotools.com/index.php/europro-forged-hvlp-spray-gun-with-1-9mm-nozzle-plastic-cup.html
Tip/cap: 1.9
Compressor: 60 gallon, 12.x CFM @ 90psi
Compressor line: 3/8" rubber hose, 50' 
Compressor line connectors: High flow quick adapters
Regulator: 3/8" at the gun. Generic brand. 
Water Removal: Have tested with and without a generic disposable at the gun, no difference in spray with/without. (suspected a cfm issue, but appears not to be the case)
Material: Target Coatings Emtech 6500 (https://artdec.ca/en/p/443/em6500-water-based-acrylic-pigmented-lacquer)
Material Specs/Spraying info: 1.8mm - 2mm cap/needle recommended. https://artdec.ca/media/catalog/specs/TC_TechDataSheet_EM6500_R4_kmRjgHx.pdf


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## wapakfred (Jul 29, 2011)

Well, you tried everything I would have suggested…have you sprayed other finishes with this gun and not had a problem?


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## wuddoc (Mar 21, 2008)

"Pigmented is a clue". Gravity affects pigment when it is sitting in a can. Pigment and other solids will settle to the bottom and adhere to each other. Have you completely stirred the material including scrapping the bottom of the can? Stirring round and round is not mixing the various solids in the material. That type of stirring only stratifies the various solids. Here are some stills taken when producing a video years ago.
Picture 1 = Pigment on bottom
Picture 2 = Stirring with stick vertical and round and round does not mix thoroughly various weighted solids.
Picture 3 = Stirring at an angle mixes various weighted solids.

Filtration may help by pouring the material through a filter as you pour it into the guns cup.


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## pintodeluxe (Sep 12, 2010)

What psi have you set at the gun? I usually spray at 30-35 psi. If it won't lay down smoothly, try thinning 15%.


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## bonesbr549 (Jan 1, 2010)

Have you run it through a viscosity cup and timed it? While the can may say right out of the can, it probably says how much it can be diluted i.e. 10% or something.

When it doubt run it through your viscosity cup and it will tell you. If you getting splatter, sounds like too thick. Cut it and try again.

Also adjust your needle/cap size.


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## JAAune (Jan 22, 2012)

Someone suggested filtering the material as it goes into the cup. That's always a good idea.

The other thing to do is check and see if material is getting on the outside of the gun's nozzle. If it is, it will keep building up until airflow finally knocks off a blob and "spits" it onto your project.


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## Nate1 (Aug 21, 2013)

I have not tried spraying other coatings. Water sprays nicely.

Product is mixed thoroughly before spraying. Product does not experience much settling or at least to the level of piling in the bottom of the 1 gallon can. I have used a gallon of this product before…I was amazed at the lack of pigment hanging out when I got to the bottom of it.

30psi. Have tried up and down 10psi with no noticeable improvement.

I am heading out to do some tests thinning it more now.

Have not ran it through a viscosity cup. Do not own one….yet. 

I have tried the 1.9mm the manufacturer recommends and a 1.3mm.

Outside of the tip/nozzle is getting boogers. When I stop I clean it off, but no that certainly does not help when spraying and could be the source.


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## 000 (Dec 9, 2015)

In line with what JAAune is saying,
Make sure your nozzle and cap are tight. 
Some guns have a clear gasket that goes under the nozzle, is it there?
Are the cap, needle, and nozzle matched #'s?


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## RichT (Oct 14, 2016)

I read this right after you posted it, before there were any comments. What JAAune suggested is exactly what I was thinking, but I couldn't figure out how to express it very well - certainly not as clearly as he did.

Anyway, I second his idea.


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## AlaskaGuy (Jan 29, 2012)

If that an gravity feed gun make sure the little hole in the top of the cup is clean. According to Jeff at Homestead finishing 90 % of gravity feed gun problems comes from than or a dirty gun.

Look at this advice see if it helps,

http://homesteadfinishingproducts.com/wp-content/uploads/2014/05/paintspraying_ver3.pdf


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## Nate1 (Aug 21, 2013)

*Splatter issue resolved!*

I was able to get rid of the splatter I was getting with both tip/cap/needle assemblies and without thinning. The 1.9mm definitely gave a wider fan of material. Thinning helped out a lot with the 1.3mm in achieving a decently wide fan of material.

Not 100% sure which tactic solved the splatting issue (my guess is the tightening), but I performed the following:

- I ensured the gun was clean inside and out (brand new gun, so not really an issue)
- Added the in cup filter (do not have any pour through filters on hand, so used what I had)
- I tightened the nozzle and cap on tighter than I would expect it to need to be. Previously I did tight with caution to the reality of soft metals are at play in these parts.
- Verified the cup's vent hole was not clogged. It wasn't.

Side note: Yes I was setting the pressure regulator while air was flowing through the gun. ☺

Thank you for your help.

*Resources*
- Spraying paint with HVLP guns: http://homesteadfinishingproducts.com/wp-content/uploads/2014/05/paintspraying_ver3.pdf
- Spitting spray gun: https://www.pittsburghsprayequip.com/2016/02/05/why-your-spray-gun-is-spitting/
- Measuring and adjusting viscosity: http://finishing.tips/measure-and-adjust-the-viscosity/
- HTVLP Troubleshooting: http://www.portlandcompressor.com/hvlp/trouble-shooting.aspx


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## wapakfred (Jul 29, 2011)

Glad you got it solved….


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## pintodeluxe (Sep 12, 2010)

Nothing quite like a sprayed finish. Glad you resolved the issue.


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## AlaskaGuy (Jan 29, 2012)

Happy you got it worked out, and thank for posting all the links.


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