# HVLP cabinet/trim spraying advice?



## MrRVK (Mar 28, 2021)

Hi everyone, I'm new here, and my latest project has finally gotten me to create an account after years of looking at projects/tips/etc.

I've been building the kitchen in our home from scratch (started Summer of 2019), but the spraying of the cabinets has been kicking my butt over the past few weeks. I have very little experience with everything and I'm learning as I go along, but everything so far I've been able to do up to my standards, except for the spraying…

I'm using a Fuji Mini-Mite 4 HVLP sprayer and after an initial learning curve, I got pretty good results with applying Zinsser B-I-N shellac-based primer to my MDF shaker-style cabinets.

The actual top coat is continuing to give me grief, however. I'm using Sherwin-Williams Emerald Urethane Trim Enamel based on the advice I got in the store for finishing my cabinets and trim, but this stuff is either very difficult to spray properly using HVLP or my skillset just isn't there even after weeks of trying (or both). I do have to thin this stuff 30% to get it to flow properly, but that seems consistent with what I've seen others share online (using HVLP).

I was finally at the point of being able to lay down a smooth wet coat, but yesterday I sprayed the final top coat on a set of 30 cabinets, only to be devestated after seeing how they dried. I have a ton of little micro bubbles in the finish, as you can see in the pictures below. I did not get any of this in any of the 18 panels I already finished or the other side of these panels (including the first top coat on the front side of them).

After pulling myself together, I sanded off 3 doors today and reapplied the finish, thinking I may have applied too thick of a coat or something, but I'm seeing the exact same result now.

The one key difference I'm seeing is that I had to open up a new gallon can for this coat, which is when these issues started. I don't have another can to test to see, but I'm heading to SW tomorrow to see if they can replace it for me to see if that's the culprit.

That all being said, this whole spraying process has definitely discouraged me a bit, since I also plan on tackling all the trim in the house after finishing the cabinets. I'm hoping you can give me some advice on something that's easier to apply, but will be as durable as the SW Urethane Trim Enamel (or better). I'm reading good things about General Finishes Enduro White Poly and I may try that (tinted to match the Alabaster SW color), but I'm all ears for advice on what will spray very smooth using my 4-stage HVLP.

Sorry for the extremely long post, but I'd love to hear from you more experienced folks on what I can improve and how I can make this part of the process a bit easier on myself.

Thanks a ton in advance!

Example of previous top coat that I was happy with (not perfect, but good enough)









And here are some pics of the terrible last coat (with the specific gallon can)


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## cracknpop (Dec 20, 2011)

Hard for me to tell by the pictures, are they little 'craters' or were they bubbles that popped leaving a divot?

Looks like a fish-eye problem to me. Could've came from: the new gallon of paint you opened, the cleaner you used before top-coat, what you cleaned your spray gun with.

Here's an article from SW about fish-eyes. You will find others on LJs and the web.
https://www.sherwin-williams.com/sw-article-pro-fisheyes

Welcome to LJs.


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## MrRVK (Mar 28, 2021)

cracknpop, thanks for the quick response.

My best guess is that they're bubbles that popped, because I can still see some bubbles intact in places. They're mostly little craters, though.

The reason I'm confused is that I'm doing the exact same thing as what I've been doing with all the other coats, the only difference is the new can.


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## xedos (Apr 25, 2020)

Doesn't look like micro bubbles to me.

Emerald really isn't suited for HVLP, I think 30% is too much thinning, and if so - you've lost much of the durability characteristics of the coating. Did you use floetrol ? What size needle/ nozzle are you using? You're aware of the long "cure" time with Emerald, yes ?

But back to the issue - are you certain you did nothing different ? New sandpaper, new tack rag, ect…..? How about the weather , or is you spray area climate controlled ? It's quite possible the paint was contaminated, but I'd put that waaaaaay down the list.


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## MrRVK (Mar 28, 2021)

xedos, I'm a bit bummed because the rep told me it would be fine in HVLP, but clearly it's not. 30% is too much I agree, but I get massive orange peel thinned less. I didn't use floetrol, just water. 1.8mm tip and yes I let them cure for a week, but after 4-6 hours it's typically cured enough to see what the finish looks like (all others without pitting).

I sanded and resprayed two doors at first to try and eliminate other factors, then a third which I took down all the way to the primer and still I got the same result. I'm not in a climate controlled booth, but the climate is very similar to the other coats.


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## SuperCubber (Feb 23, 2012)

What about Sherwin Williams ProClassic Acrylic Alkyd? I used it on the cabinets at my last house. Had to thin it some, but it sprayed very well and I'm going to use it again in a month or so on another small cabinet project.


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## CaptainKlutz (Apr 23, 2014)

Welcome to LumberJocks!

Can't tell from pic if you have fish-eye (contamination), or you injected air bubbles during your thinning/mixing process? Injecting micro bubbles during mixing is a common problem with WB finishes.

+1 Floetrol might help
Try adding 10-15% floetrol and as little water as possible. Floetrol will usually fix orange peel when spraying WB finishes, if it is compatible.

Most WB enamels have heavy body, and using a larger tip will reduce the amount of thinning needed. 
So try a larger tip if you have one.

Personally not a fan of SW Emerald urethane enamel paint. Used it once in an exterior application, with HVLP pressure cup gun using 2.2mm tip. Had pressure set to max recommended for gun too. Stuff didn't want to lay down a nice thin wet coat. Needed to put down heavy 4-5mil layer thinned with Floetrol, or didn't flow out very well.

Would never attempt to use house/trim paint like Emerald on cabinets. But sounds like you are half way done, and only choice is to figure out right combination of tip size, thinner, and spray pressure?

IMHO - the SW store recommended Emerald only because they were a retail house paint branch; not an industrial branch with professional grade finishes for cabinet makers. The industrial SW branch would likely have recommended pigmented lacquer or pigmented Conversion Varnish, then offered the Emerald for brush painting the trim after cabinets are installed. Try to find industrial SW distributor for your next cabinet project.

Best Luck!


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## rwe2156 (May 7, 2014)

No expert, but my gut tells me it's the amount of thinning. I've heard windshield washer fluid can be used. SW has great paint, but my experience is the guys behind the counter may or may not give the best advice. They recommended ProClassic for some vanities and they came out ok.

IMO CK has good advice. The really good stuff (KCMA rated) like Kem Aqua is sold through another division. I'm pretty sure you have to buy in 5 gallon buckets.

Personally I would add a clear topcoat like a water based lacquer.

I'm pretty much sold on Target Coatings products, The have a pigmented lacquer and topcoats that are excellent. As well, if you're a newbie, the people are very helpfully.


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## MrRVK (Mar 28, 2021)

Thank you all for your responses, it's super helpful to get perspectives from folks that are more experienced. (Already sounds like this community is much more helpful than what I experienced on Reddit)

@SuperCubber, I tried ProClassic Acrylic Alkyd on a previous project (granted I brushed and not sprayed), but the extreme cure time turned me off. It took literal weeks for it to stop being tacky, and SW wasn't much help when I asked them about that. Maybe spraying thinner coats will alleviate that?

@CaptainKlutz, I thought maybe it was user error, so I mixed up a new batch for the third door that I sanded down to the primer, but I still got similar pitting/craters. Good tip on Floetrol, I'll try that instead of water. I'll also try a 2.0mm tip instead of the 1.8 I've been using.

@Robert, thanks, Kem Aqua seems like the better option for HVLP from what I'm reading, but the guidance of needing to move air constantly over it while drying concerns me a little (I'm just letting them dry on a rack in my garage, moving air would probably kick up some dust that would get in the finish?).

Couple other questions:
- Can I just walk into a Sherwin-Williams Commercial store and ask them about their advice, possibly bringing one of the panels? Not sure if that's something that only businesses can do.
- I've been thinning with plain tap water, but should I be using distilled water instead to avoid contamination with the water?


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## CaptainKlutz (Apr 23, 2014)

> Couple other questions:
> - Can I just walk into a Sherwin-Williams Commercial store and ask them about their advice, possibly bringing one of the panels? Not sure if that s something that only businesses can do.
> - I ve been thinning with plain tap water, but should I be using distilled water instead to avoid contamination with the water?
> - MrRVK


- Yes. Can walk into SW with panel and ask for help.
They always try to help, but experience in store varies a lot and will determine quality of help. When you find the right person, one who supports cabinet shops or furniture makers; his advice will be golden.

Will caution that you might not find these folks in store right now. Many of the industrial sales/marketing folks are working from home due Covid. My industrial distributor has enough volume and staff, they rotate weekly so one wood coatings rep is working at warehouse everyday.

FWIW - But SW is strange beast. SW has 3 tiers of distribution. 
- Retail - house paint stores (Usually WB only). 
- Commercial - Focused on folks who paint things for living (90% WB building paint, 10% solvent enamels or lacquers).
- Industrial - Sells everything, and has separate profit center for distribution hub to all local stores. 
Each store is independent profit center, and sometimes the compete amongst each other. They all will sell to individuals. If you only want a gal of acrylic house paint, the industrial folks will send you to retail store. If you ask for Sherwood, Kem Aqua, or Slayerlock brands; most commercial stores will send you larger Industrial outlet, unless they stock products used by local cabinet shop. The commercial store inventory is driven by local demand.

The SW Industrial brands are technically only for sale to professionals, thanks to EPA regulations on solvents and airborne emissions. As long as you act professional, need several gallons for large project; have never had SW Industrial branch send me away. The WB tend to be sold to anyone. Only time I had SW ask for federal/state EPA waste disposal permit was to buy solvent paints in Peoples Republic of Kalifornia.

Just be sure you open a business account, so you get jobber discounts. Retail prices are stupid expensive ($150/gal, instead of $85 for WB). My son works part time for one of the commercial stores. We get a 'large' family discount based on ridiculous retail. My jobber account offers better pricing on everything except SW solvent products.

- Water quality for thinning? It depends on coating chemistry. Polyurethanes and/or enamels are more sensitive to contaminates than acrylic. If you have hard water or high salinity levels; need to use distilled or RO water. 
Also have to be careful in regions with high humidity, depending on city water source. Reservoir water always contains low levels of algae. The chlorine is supposed to kill it, but it's not 100% perfect. Using 'tap' water in acrylic house paint, can create mold inside the paint in places like Pacific NW, or near ocean where drying with 60% RH outside.

PS - not a professional painter. Just an amateur, and part time polymer chemist.

Cheers!


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## MrRVK (Mar 28, 2021)

@CaptainKlutz, thanks again for taking the time. Funny because I just went to the Commercial & Industrial SW in Mukilteo and my experience was very similar to what you said. None of them there really had the experience to tell what was going on and they gave me the same reasons that I already read on the internet (surface contamination, thinning/flow issues). They did keep my panel and said they'd have a rep look at that, so hopefully they'll be able to come up with their own opinion.

The only reason why I remain skeptical is that I've already painted 18 panels (2 coats on both sides) and these 30 panels have 2 coats on one side and the one coat on the other side that did not have this issue at all. Same Fuji 4-stage HVLP with 1.8mm used, same water-thinning process.

They did tint my last gallon bucket that I purchased, so I'll try with that and see if I get similar results. If not, I'm going to think it's still that one gallon bucket that's the culprit…


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## Mike_D_S (May 3, 2012)

Though I haven't done a lot of spraying SW in general, but I have sprayed a fair amount of the ProClassic Acrylic and i have to thin well in excess of recommendations. Even thinning it like I do, there is a fine line between just right and runs/globs. The other thing I find is that thorough mixing is a requirement for the ProClassic and i give a gallon at least 2-3 minutes of mix time, if you're not mixing that long you may want to up your mix time?

ProClassic does take a long time to cure, but thinned with water about 25% by volume and sprayed on I could lightly handle in about an hour and it was relatively impervious to fingerprints in a couple of hours, though I usually let it cure several days before doing anything major. It will stick to itself or other items for longer than that through, so you have to wait for doors/drawers or you risk some issues.

I've never had the exact problem you're having, but I'd try a quick test. Take a new piece of board and do a quick base coat of shellac then spray again. If you get the same problem you're at least eliminating potential issues with the other base coat.

Also, I've had the exact same experience with the SW staff in the retail stores where they give mixed value advice, often delivered with confidence so you figure they know what they're doing. Finding a shop that caters primarily to professionals is good advice as I found the advice more helpful. In addition to paints, lacquers, etc the pro shop I went to in Houston also stocked sandpaper and other finishing related items for pretty fair prices. So that was handy.

Mike


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## tomsteve (Jan 23, 2015)

what did you clean your gun with?


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## xedos (Apr 25, 2020)

RVK - Capt. has given you a good roadmap.

I'll add that floetrol prob. isnt gonna get you to the correct viscosity by itself. You can try, but I'll bet you're going to need water too. Distilled water is best and is cheap at Wally World, so I'd use it so as to elimibnate one avenue of potential problems. Use the larges needle Fuji has - I think it's 2.2mm.

Butyl Cellosolve is used as a cure for micro bubbles with soem coatings, especially Kem Aqua. Dbl. check with a rep to see if it's compatible with Emerald.

You might try renting an airless rig or handheld from the Depot or other rental place. Those will easily handle Emerald and lay down a smooth finish. Bottom line is, Emerald is really too thick to spray with 4 stage HVLP.


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## MrRVK (Mar 28, 2021)

@MikeDS, thanks for weighing in. It'll definitely be something I'll look at once I tackle my next trim project and continue my spraying journey  I do mix for 2-3 minutes I'd say, I'm looking for a very consistent viscosity throughout when mixing/thinning and I slowly stir everything together with a wood stirring stick.

I did take one of the panels down to the primer again and resprayed and I got similar results with the same gallon bucket. I got my last gallon bucket tinted yesterday, so that will hopefully tell me if that gallon bucket was really the culprit. SW will probably never admit that it was, but if I find it is, at least I can move forward.

@tomsteve, I have the same cleaning process as all the other coats/times: use brush cleaner to spray through the gun until clear brush cleaner is coming out the other end. Use small brushes to get everything out, soak the removable parts in brush cleaner for a few minutes, and lastly rinsing everything with soapy water and drying with clean towels.


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## MrRVK (Mar 28, 2021)

@xedos, thanks, and I'll experiment with the floetrol and/or water mix. Agree that distilled water will eliminate another variable. The 1.8mm has been working now, but if I find I need to add too much water even with the floetrol, I may bump up to the 2.2mm.

One of the reasons I'm being a bit stubborn with the HVLP is that I want to keep the mess to a minimum. And airless would throw a lot of paint around, but renting one is a good last resort option, thanks!


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## CaptainKlutz (Apr 23, 2014)

> Butyl Cellosolve - xedos


+1 good stuff and another professional recommendation!

LOL, 
Have a love/hate relationship with the Butyl Cellosolve. It has the slowest evaporation rate, of the readily available, and low viscosity solvents; that is also soluble in water based coatings.

Most WB coatings use very small amounts of Butyl Cellosolve as carrier for curing agents, or to improve the wet out of sheen changing fillers; as it makes them compatible with water. It is called safe by some cleaning solvent mfg (it isn't). You are supposed to be wearing a respirator when spraying anything, including WB; but adding 5-15% Butyl Cellosolve makes the coating stink. It can also take several days for smell to dissipate from coating with low temperature/high humidity conditions. Once you add it, you ruin the low VOC/Green benefit of using WB coating.

Despite the negatives: Butyl Cellosolve will solve a myriad of spraying problems, like micro bubbles, poor flow out, and/or orange peel. And is especially useful in low humidity & high temperature environment found in my Arizona spring/summer/fall weather. Have to add Butyl Cellosolve as retarder to any WB finish I spray 8-9 months of the year.



> The only reason why I remain skeptical is that I ve already painted 18 panels (2 coats on both sides) and these 30 panels have 2 coats on one side and the one coat on the other side that did not have this issue at all. - MrRVK


 Just because you spray a coating OK one day, and not the next; does not mean there is problem with coating. It could be your environment? Environmental issues account for massive amount to problems with sprayed finishes.

If the early panels were sprayed on day with lower temp; the coating stayed wet longer and had time to clear the bubbles. If weather on day two is higher temperature and higher humidity, the coating could be drying before the coating has time to release the bubbles. Some coatings are very sensitive to environment. Have learned hard way, if I attempt to spray Rustoleum alkyd enamel above 90°, the results are always bad.

As others have mentioned, it could also be an issue with cleaning, or surface contaminate from/after sanding. If you used MS to clean the sanding surface, and then sprayed short time later; could be MS trapped in old coating made the bubbles.

While we all like to blame the coating, be sure you have not changed your process, and/or your environment; that created conditions resulting in undesirable finish.

Best Luck.


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## MrRVK (Mar 28, 2021)

@CaptainKlutz, appreciate the critical take for sure. The temperature was more or less the same, and the time it took for the paint to cure enough to not be "wet" anymore on the surface was roughly the same as well (~3 hours). Agree that there's a lot of variables as I'm working in a non-controlled environment, so that's why I want to try the new bucket to see if that solves it. For my own sanity, I may spray another test piece with both buckets if the new one turns out fine, just to do another double-check under similar circumstances.


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## SuperCubber (Feb 23, 2012)

> @SuperCubber, I tried ProClassic Acrylic Alkyd on a previous project (granted I brushed and not sprayed), but the extreme cure time turned me off. It took literal weeks for it to stop being tacky, and SW wasn t much help when I asked them about that. Maybe spraying thinner coats will alleviate that?


Wow, I did not have that experience. I hung the cabinet doors two days after I sprayed the final coat.


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## azwoodworker (Jul 9, 2013)

"but everything so far I've been able to do up to my standards" Love that statement. I feel the same way about my work.

A couple of points in spraying with the trim. You stated you did fine and then the final wet coat you ended up with the potted finish. Fuji manual has 20 to 30 percent thining for the finish you are using so based on that it might not be excessive. However, the manual does give this point on set up: 
" The low pressure allows the material being sprayed to be laid on gently and not blasted on. Lower velocity translates to less bounce-back and less overspray. Don't forget that once you have
adjusted the viscosity and size of the spray pattern, you must then adjust how much paint flows through the gun. Then you should try reducing the air pressure at the air control valve to reduce bounceback and overspray"

It looks like an overspray to me. The manual as above should be checked if you changed the thickness to put on the final wet coat.

The second point is the pattern or plan you are using in spraying that includes not over spraying where you just sprayed. One common error people have with spraying is not flowing in a pattern away from where you have already sprayed so you get overspray on where you have just sprayed. Move left to right or right to left but always away from where you sprayed, and ensure you are not crisscrossing or spraying the piece but getting overspray on what you sprayed. The Shellac-based primer is more forgiving than the final trim coat you are using from my experience.


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