Poly Acrylic with HVLP

Taigert | Posted in Finishing on October 6, 2009 02:09am

Has anyone sprayed Poly Acrylic with a HVLP? The only brand I could find around here is Minwax brand. I do like the idea that it is a water based product.

I have a customer just do a 180 on me when I took the job on of cutting down a mean old twisted pc of Walnut, and making a Mantle from it he wanted it vinished with Tung Oil. Now he says his wife wants it finished with Poly Acrylic.

I’ve never used this stuff before, but I’ll give it a shot.

Who makes the best product, does it require thining, if so will mineral spirits be best?

Minwax says to not thin out? They also suggest using it as a brushed on product. How does it do when sprayed with a HVLP?

Thanks,

Taigert

Replies

DonStephan | Oct 06, 2009 02:35am | #1
Not sure which type of product you are looking at. If it's a water borne finish, mineral spirits would not mix well with it.

If Minwax says don't thin, and brush only, I'd go along with that. I'd make up samples using two ends of a scrap piece of walnut, one with tung oil and the other with a couple coats of the Minwax product. It's possible the two ends will look dramatically different.

Had to use the Polycrylic perhaps 20 years ago on a job, and didn't like it very much. Brushed it on per the instructions. Didn't think the dried finish was very hard.

Just my two cents.
Senomozi | Oct 06, 2009 03:09am | #2
The first step is to determine if thinning is necessary in the first place. Your HVLP system probably came with a viscosity cup and instructions on how to use it to ensure the material you are spraying is at the right viscosity. If it is then go ahead and test it on scraps to get the feel for it. If the product is too thick (which I bet it will because it is meant to be brushed) then you could thin it down with water. HOWEVER, since the product label says not to thin it down I would forget about that product and use something else. The customer will never know. There are a number of manufacturers out there that make waterborne products at spray viscosity. I use Can-Lak Aqua-Syl. Tomorrow I am picking up my first gallon of Mohawk Pre-Cat lacquer. General Finishes also make a similar product.

All that being said, I strongly suggest making a sample on Walnut and showing it to the customer. Water-based finish on walnut does not look so good in my opinion unless you first apply an oil or a "natural" stain (minwax makes it).

Edited 10/5/2009 8:13 pm ET by Senomozi 

Edited 10/5/2009 8:14 pm ET by Senomozi
GregoryPaolini | Oct 06, 2009 01:59pm | #3
I spray MW polycrylic all the time... I'm using an HVLP conversion gun with a 1.4mm tip, and I thin the polycryllic down about 10% with distilled water. I spray light coats - If you do a heavy coat, the poly will take forever to cure.

Another product I like is Resithane waterbased laquer from Hood - Another woodworker turned me on to it, and it really does a great job - You'll have to order it from hood finishing though...

Hope this helps

Gregory Paolini

http://www.GregoryPaolini.com

Custom Furniture, Cabinetry, and Woodworking Instruction
Taigert | Oct 06, 2009 05:10pm | #4
Thanks for the input

Yesterday when I wrote this post I had mineral spirits on the brain. Every time I get mineral spirits on my hands they dry out for a week, and it drives me nuts. And I had just finished cleaning up a earlier job with mineral spirits. My brain was thinking water but it came out mineral, go figure?

I have some of this walnut scrap I'm going to use for making test pcs. before the final shoot.

I has made up 4 different combinations of using tung oil for the customer to pick from, seen as he had originally told me he wanted that for a finish. The mistake I made was sending him home with the sample pcs, that gave his wife a open door. Once she became involved, she assumed command of the ship.

This piece of walnut is out of the customers Great Grand Mothers homestead home, which was over 200 yrs old. The house was framed with walnut, back then house were built with what ever was nearby, and this property was covered in walnut. When this piece of walnut arrived at my shop it looked like a beaten up old Railroad tie. It took a lot of work to get into a presentable condition, now it is beautiful piece of walnut. Once finish it will look beautiful mounted proudly above the fireplace.

Taigert

I'll post some pics later this afternoon seen as my camera is wanting to part with images contained within. My son will pull them out this afternoon, it doesn't dare withhold them from him.
paulbny | Oct 07, 2009 04:25am | #5
I've sprayed a couple of gallons of Minwax PolyAcrylic with a PC conversion gun and it works great. Thin coats are a must. Last time I did it I was spraying 12 cabinets and the timeing worked out perfect. As soon as I finished the last cabinet and had bottle of water the first was ready for a second / third / fourth / fifth / sixth coat. Plus my shop doesn't stink for the rest of the day.

Best of luck

Often in error but NEVER in doubt!