# Water based polyurethene with HVLP gun



## ms1780 (Nov 8, 2011)

I have a low quality HVLP gun, although I have sprayed paint and clear on 3 cars with good results. My question is can I spray water based Minwax poly with it? I have built a dresser to match a toy box I built my son a few years back and want them to match. I sprayed the toy box with spray cans, but the dresser is big and the cans are about $9 each with tax so I would rather buy a gallon. I am considering buying the small Kobalt gun found here for the tighter areas. I have used a precat laquer from Sherwin Williams to spray cabinets using an airless sprayer with a fine tip with excellent, near perfect results, but it was not my sprayer and clean up is a pita. The laquer product says it can be sprayed using an HVLP gun, but I am not sure how well it will match the toy box. I assume the stuff that says "dull rubbed" would be the equivelent of a satin poly. Thanks in advance for any advice.

Mike


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## Taylormade (Feb 3, 2011)

Mike, absolutely you can, and, for me at least, it's the only type of poly I'll shoot through my HVLP gun. Otherwise cleanup just never seems to be quite done. The only thing I can offer is to be careful and let each coat dry... I sprayed minwax poly on a shelf I created recently and went pretty heavy with the last coat... it ended up leaving pink marks in it... odd for sure.


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## Tom5151 (Nov 21, 2008)

I have sprayed many many gallons of WB poly with this HVLP sprayer:

Amazon.com: Wagner 518080 Control Spray Max HVLP Sprayer: Home Improvement

...and the results have been very good...


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## cabinetman (Jul 5, 2007)

Waterbase polyurethane is very easy to spray. Applying thin coats is the best way. I try to spray articles vertically. That keeps the media from pooling or puddling. It also keeps the dust off. Just use a lot of light so you can see how wet your passes are, and try to prevent runs. Do some practice with cardboard and just water.












 







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## ms1780 (Nov 8, 2011)

Well while I was at lunch I went to Sherwin Williams and talked to the guy about my options. He suggested Poly can be sprayed with an HVLP gun, but it tends to get small bubbles in it. I don't know if he knows what he is talking about, but those guys are usually pretty good. So, I bought the dull rub laquer which is what I have sprayed before anyway so I don't mind. It is about the same price which is plenty (40 a galloan) and you have to clean it up with laquer finish which stinks, so I guess the water based poly would have been better, plus the pot life on the laquer is only 6 months and it only comes in gallons. I may wish I would have waited for the responses and bought the poly. The main thing is the dresser turns out nice. I will post pics.


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## Tom5151 (Nov 21, 2008)

ms1780 said:


> Well while I was at lunch I went to Sherwin Williams and talked to the guy about my options. He suggested Poly can be sprayed with an HVLP gun, but it tends to get small bubbles in it. I don't know if he knows what he is talking about, but those guys are usually pretty good. So, I bought the dull rub laquer which is what I have sprayed before anyway so I don't mind. It is about the same price which is plenty (40 a galloan) and you have to clean it up with laquer finish which stinks, so I guess the water based poly would have been better, plus the pot life on the laquer is only 6 months and it only comes in gallons. I may wish I would have waited for the responses and bought the poly. The main thing is the dresser turns out nice. I will post pics.


I have never had a problem with bubbles when spraying WB. Others may have but I have not seen that at all. The only time I get bubbles in wb poly is if I am brushing it and/or the can has been shaken. I like the Parks Pro Finishers or the General Finishes products


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## ms1780 (Nov 8, 2011)

Oh I certaintly am not arguing with you. I believe those who have done over those who have read any day. I just was not armed with this info when I went to town. I should have waited and I am sure I can't return the laquer now that it is catalyzed. I am kickin myself in the ars right now because I would have rather used WB Poly.


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## Tom5151 (Nov 21, 2008)

ms1780 said:


> Oh I certaintly am not arguing with you. I believe those who have done over those who have read any day. I just was not armed with this info when I went to town. I should have waited and I am sure I can't return the laquer now that it is catalyzed. I am kickin myself in the ars right now because I would have rather used WB Poly.


Oh no no.....I wasn't taking it as arguing at all. Sorry if I came across that way...my bad......I was just giving you a little more amo/info in case it was helpful......:thumbsup:


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## ms1780 (Nov 8, 2011)

No..its good I did not think you were. Some people just get really standofish on these forums. BTW, my HVLP gun is a gravity feed hooked up to a 60 gal compressor. When I spray clear on cars I ususally regulate it down to about 40 at the compressor then down to about 13 -18 at the gun. I notice the pic one guy put on here of the hvlp he uses is like the compressor is part of the gun, would this make any difference?


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## Tom5151 (Nov 21, 2008)

ms1780 said:


> No..its good I did not think you were. Some people just get really standofish on these forums. BTW, my HVLP gun is a gravity feed hooked up to a 60 gal compressor. When I spray clear on cars I ususally regulate it down to about 40 at the compressor then down to about 13 -18 at the gun. I notice the pic one guy put on here of the hvlp he uses is like the compressor is part of the gun, would this make any difference?


I honestly do not know the answer to that question but I am sure there will be some very knowledgeable folks out here who will...with the inexpensive one I use the gun is attached to a turbine system by a vacuum hose. no compressor at all. 

post pics of your project when you are done. would love to see how it turns out.


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## aardvark (Sep 29, 2011)

I have to break in and ask a few things along the same lines as the discussion.

I'm to the point of needing to change up from spray can clearcoats to (possibly) waterbased poly, using an automotive spray gun. I am used to shooting automotive laquers, but the odor , lack of ventilation and cleanup is bothering me.
My finishes are generally satin, not gloss. 

What I'm wondering is if the automotive gun is suitable or if there is a tip/needle change ? These guns are not HVLP, but standard air mix guns.
Also is there a particular brand some of you prefer?
Is the finish product hard surfaced after drying like lacquer or softer.
How well does it flow?


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## aardvark (Sep 29, 2011)

One other concern. 
I spray can painted a surface with what appears to be a lacquer based spray can clearcoat. 5 coats.
It is needing sanded down some, since the surface wood seems to have raised with it a tad, leaving a rough finish. After sanding, will a water based polyurethane react with the surface I already have down?
I'm suspecting it shouldn't but a few opinions would be appreciated.

Thanks.


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## cabinetman (Jul 5, 2007)

ms1780 said:


> I notice the pic one guy put on here of the hvlp he uses is like the compressor is part of the gun, would this make any difference?





Tom5151 said:


> ...with the inexpensive one I use the gun is attached to a turbine system by a vacuum hose. no compressor at all.


The turbine type (self contained) is probably what ms1780 was referring to.












 







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## cabinetman (Jul 5, 2007)

aardvark said:


> What I'm wondering is if the automotive gun is suitable or if there is a tip/needle change ? These guns are not HVLP, but standard air mix guns.


I've got several of those guns and found no need to change needles or tips. With the controls on the gun for fluid/air mix, a good compromise can be reached to be thoroughly atomized with the correct air pressure and pattern. What sprays lacquer sprays WB poly.



aardvark said:


> Also is there a particular brand some of you prefer?
> Is the finish product hard surfaced after drying like lacquer or softer.
> How well does it flow?


I've used several brands of WB polyurethane, and found very little difference in viscosity or quality of finish. Parks Pro Finisher does an excellent job as a topcoat. WB polyurethane becomes a hard durable finish...as durable as lacquer IMO, if applied in many thin applications allowing each one to dry.



aardvark said:


> One other concern.
> I spray can painted a surface with what appears to be a lacquer based spray can clearcoat. 5 coats.
> It is needing sanded down some, since the surface wood seems to have raised with it a tad, leaving a rough finish. After sanding, will a water based polyurethane react with the surface I already have down?
> I'm suspecting it shouldn't but a few opinions would be appreciated.
> Thanks.


Applying a WB polyurethane over a completely dry lacquer should not react. Again...thin coats allowed to dry work best.












 







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## aardvark (Sep 29, 2011)

Thanks so much Cabinetman
It reassures me that what I have on hand (cept the purchase of the wb poly) is adequate. 
I used to shoot cars @ 60 lbs psi, but I am assuming that can be dropped a shade.
Now all I gotta do is check my guns for gaskets and see their condition. 

And thanks for the reassurance on the lacquer base on the piece I shot , not being an issue. I think I might sand it a solid day + before coating, to assure it is set up and aired out well. Currently the fool thing is still slightly off gassing 2 days later.

Appreciate you filling me in. This is a first for me, shooting wood and wb poly.


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## ms1780 (Nov 8, 2011)

Here are some pics of the dresser almost finished. I am going to stain it and then spray it with several coats of the laquer I bought at Sherwin Williams today. I think it is turning out really nice.


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## aardvark (Sep 29, 2011)

^ More patients than me for fine joinery. Looks good and I can just see in my head, the final finish.


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## icicle (Nov 29, 2011)

Looks Nice


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