# Thinned Acrylic Latex through HVLP?



## signmonger (Aug 14, 2010)

Greetings, Folks.

I am hoping for some input from those with better knowledge of paint chemistry than I. Here is my proposal/question:

I use mostly 100% acrylic latex paints for high quality exterior signs (usually applied with roller/brush). Recently, I began using Benjamin Moore's Aura exterior acrylic latex paint, and, overall, love it, but would like to spray it with my HVLP on moderate sized carved panels to avoid brush marks. Even when adding BM's 518 extender, Aura dries a bit too fast for this - both a blessing and a curse. 

BM tech's tell me that thinning Aura with their 518 extender and water sufficiently to spray with HVLP will produce an inferior coating, but I'm not sure I totally believe their advice, since their frame of reference is painting houses (i.e. large outdoor areas), whereas I'm working on much smaller areas inside, and can closely monitor drying rates, tack and film build. So, here is what I intend to do, and hope for some knowledgeable input:

I intend to thin Aura exterior with the recommended max. of 4 oz of 518 extender per gallon, plus enough water to get to a 45-50 second drip from viscosity cup. Using HVLP (2.5mm tip), I would spray light coats back to back to provide the equivalent of a normal, rolled, coat. Aura dries so quickly that I think that I should be able to come back to the beginning of my spray pass just when the majority of the extra water has flashed off for another light coat while still wet. Repeat a couple of times, let dry for the recommended time (4 hours), and repeat the process one more time for the equivalent of two rolled coats. 

In theory, this should give me good film build without compromising good adhesion within the paint film. I have used this technique for color blend effects with good results (over rolled base coat), but am concerned about film durability when used this way for the primary base coat.

Is there any likelihood that the extra water will somehow interfere with the curing process, or weaken the cured paint film somehow?

Thanks in advance for your input.

Todd.

PS - I know that airless would be better suited for latex, but HVLP is much better suited to small projects in a small shop. Much less overspray, and I already own HVLP.


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## BrushJockey (Mar 15, 2009)

Personally, I think you're on a good track. Just play with it and see what works. We've been thinning waterbornes to go through HVLP forever. I use a little extender and water ( about equally) in my aura for rolling too. 
Some fear messing with paint at all- I have seldom had a problem, and I have clients I see over a long span of time so I know if something has failed.


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## straight_lines (Oct 17, 2007)

Yup figure out what works best through trial and error.


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## NCPaint1 (Aug 6, 2009)

Why not just use an airless with a fine finish tip and skip all the monkeying around? Am I missing something? Im no hvlp pro so im just asking.


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## signmonger (Aug 14, 2010)

Thanks for the input, BrushJockey & Straightlines. 

NCPaint, there are several reasons I wish to try to stay with HVLP rather than airless.

First, I don't currently own an airless rig, but I do own a decent HVLP unit. Also, the manner in which I use a spray gun is very different from a house painter. I often spray several different colors from small cans (often quarts) all in a single afternoon, sometimes in very small quantities (like spraying a single line of text through a mask, or painting a carved sign panel which is only 2' across). Cleanup/color change for my HVLP is about 10 minutes, with very little wasted paint. And then there is the overspray problem. I have a small shop (25'x32', two floors), and often have it filled with signs of many shapes, colors and sizes. HVLP is ideal in that it throws very little overspray, so I don't have to go to great lengths to cover everything. I understand that airless throws a good deal more overspray than HVLP.

I haven't yet found a quality airless rig which is suited for such small and varied jobs, especially at a price I can afford. I'm open to suggestions, so if you know of an airless rig which would be suitable for the kind of work I just described, I'd be grateful.

Thanks,

Todd.


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## NCPaint1 (Aug 6, 2009)

Graco pro shot...or the Titan busted POS equivalent. Both airless units. They have a cordless, and now a unit that is electric. Also, you can get the liners for the cups, which would speed up cleaning. Not to mention less fuss timing your paint. Just a thought, throwing it out there.


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## Paintuh4Life (May 20, 2009)

BrushJockey said:


> Personally, I think you're on a good track. Just play with it and see what works. We've been thinning waterbornes to go through HVLP forever. I use a little extender and water ( about equally) in my aura for rolling too.
> Some fear messing with paint at all- I have seldom had a problem, and I have clients I see over a long span of time so I know if something has failed.


I agree, go forth and spray. I'm a big HVLP fan. I love the control. I do a lot of cabinet work and I like the finish. On new kitchens for instance, I'll spray the primer (usually BIN) with an airless and put a couple of top coats on with the HVLP.


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## IHATE_HOMEDEPOT (May 27, 2008)

I agree with the idea of using a Groshot. You are likely a perfect candidate. Airless is way to much cleanup prob. but it would allow you to get better coverage faster. HVLP's are easy to setup/cleanup although you do need to fire up a compressor unless you have a turbine $$$$.
For something as delicate as a sign I would think it would be nice to at least back brush the primer though. I read a post a while back from a chemist I think on this forum and he said to use distilled water so as not to introduce any unessessary chemicals (mainly chlorine). I think it was good advice.

P.S. I would bet you will have different dilution ratios based on darker vs. lighter colors.Keep track of exactly how much extender you use for sure,maybe even get some measuring devices.


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## johnthepainter (Apr 1, 2008)

it might work fine if you have a turbine big enough.

if you have to thin it down real far due to a small turbine,,,youll likely take all the guts outa the aura.

you did say "high quality".

what size turbine do you have? thats what it hinges on. a small- medium sized turbine will not cut the mustard,,,youll have to thin it down way to far. if not itll be orange peely.

btw, i use aura for my signs background also,,,,sometimes for the lettering. (typically one shot)

how about some pics?


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## signmonger (Aug 14, 2010)

HighFibre,

I've got an Earlex 5000 two-stage HVLP unit I bought a few months ago. Great unit for the price ($275). I did a ton of research before buying it and found that it's about as good as $800 units like the Fuji's.

I posted some pics of some of our work (will post more as time allows). Also, I have a very outdated website with a partial gallery at www.distinctsigns.com I'll give it an overhaul this winter, but for now you get the idea of what we do (husband and wife shop).

I used to spray with a conventional gun, but found that the overspray was a giant pain in the neck in a small shop. HVLP solves that problem very well.

I'm also considering a compressor driven HVLP gun, as I have a monster compressor that I also use for sandblasting (35 cfm @120 psi). I'm thinking that such a unit might be a decent compromise between HVLP and airless.

We used to use a lot of One Shot and Chromatic sign paints, but stopped using them as we found that they didn't last. After about six or seven years they would chalk and fade terribly, often leaving chalky "drip" marks on the background color. I've since switch pretty much entirely to premium 100% acrylic latex, and now get signs which look good for around 15 years or so. IMHO, 100% acrylic latex is the only way to go for long service exterior signs where applicable. We use mostly solid wood (pine, cedar, redwood or cypress), MDO, Extira, HDU foam and Sintra, with occasional forays into aluminum and other substrates.

Thanks for your input.

Todd.


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## optimal (Feb 5, 2010)

We shoot industrial coatings through a pot sprayer and reduce water reducable enamels in order to spray a fine finish. Reducing the paint will be fine and remeber that when you reduce the paint the gloss finish may dull due to diluting. Also keep in mind that if you recoat to quick and your initial coat has not cured enough the dry time will be extended and the final finish will take longer to dry.


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## signmonger (Aug 14, 2010)

Status report:

Sprayed a small carved panel earlier today as described. Used 1 oz. of extender and 8 oz. of water to 16 oz. of Aura exterior, resulting in a 45 second viscosity cup drip.

No problem. Laid out like glass. Got good film build very easily and rapidly. I did notice that very light coats back to back worked much better than wetter coats. I think I could dispense with the extender next time around, as it slows down dry times (not necessary with the amount of water I added). 

I'll post a couple of pics after the panel is more complete.

FWIW, I called a techie at Insl-X paints earlier today with a similar question about thinning Stix water based primer for HVLP. He told me what we all know/suspected: the only thing that changes is film thickness/hide per coat.

Todd.


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## admirableptg (Oct 23, 2008)

We have a capsray 4/6 stage turbine. when we spray acylics, dont add too much extender as it can effect the durability. if you cant push it through borrow a larger hvlp. if you thin too much it will not cure properly imo www.admirablepainting.com


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## icecold (Apr 27, 2012)

For spraying latex you should get at least a 4 stage turbine, Graco or Capspray, I have both (Cap Spray 115 and Graco 9.5) and I spray latex, on interior trim and doors, all the time. Also get bigger size fluid set, like #4 and 5, it will spray nice and you will only need the extender, it wont change the sheen on the finish like water does.


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## HeadHoncho (Apr 17, 2007)

You need a bigger turbine than the earlex 5000, I know this because I have a earlex 5500 and it just doesn't have enough to get latex to spray properly. If you get it to thin it will take forever to get a build and you start getting runs! 

If I where you I'd get a cheap airless like $300 graco tradeworks from SW and use a regular 209 tip and turn the pressure down. This will give you a good finish with minimal overspray and you will be able to paint faster!


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## Oden (Feb 8, 2012)

I have a four stage capspray 9100. I have no problem shooting acrylic through it with very little thinning. Nice machine to have on hand really. For me it's a convenience but for the signmonger a four stage or bigger might be a 'gotta have it'.


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## nlucero (Jan 21, 2013)

*TItan Capspray 105*

Is anyone familiar with thining out Latex paint deep base with out changing the color of the paint and not having orange peel like results. Can latex paint be sprayed out the the HVLP and have the same result of the fine looking oil base paints? Please give me some tips. Painting hollow metal door frames and have tried all settings air flow. Also followed manual instructions for thining out latex. THanks for the help


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## paint_booger (Jul 1, 2007)

Try a larger needle.


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## RH (Sep 7, 2010)

IMO spraying any type of latex with an HVLP that's less than a four stage would be an exercise in futility. Damon T. has played around with his a lot and seems to have gotten some good results. 

I really like a lot of things about my HVLP (4 stage FUJI - great with alkyds) but I think you have to just have to pick a latex/waterborne product you like and experiment with it a lot though the machine you have until you get decent results.


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## Damon T (Nov 22, 2008)

Yeah I replied on the other page he posted same question on


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## Painter One (Feb 5, 2012)

HeadHoncho said:


> You need a bigger turbine than the earlex 5000, I know this because I have a earlex 5500 and it just doesn't have enough to get latex to spray properly. If you get it to thin it will take forever to get a build and you start getting runs!
> 
> If I where you I'd get a cheap airless like $300 graco tradeworks from SW and use a regular 209 tip and turn the pressure down. This will give you a good finish with minimal overspray and you will be able to paint faster!


I have onhe of those tradeworks---I will try that sometimes, but I lent it to a pal and not so nice he returned it with the ball stuck---I need to figure out how to fix that....


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