Adding An Extender to Polyacrylic Coatings

[RevRenzo]

As a professional furniture refinisher, I was anxious to take advantage of the benefits of the water-based coatings now available. One of the primary complaints about Polyacrylic and other waterborne products, is the fast drying (sometimes too fast) and brush marks that are very difficult to avoid and hard to remove once present. I have experimented with "thinning" polyacrylics with an extender, specificially, General Finishes EF Extender, available from McFeely's website. I have had excellent results mixing small amounts of EF Extender into a a small quantity of Polyacrylic. The proportion depends on the amount of "thinning" you wish to impart on the top coat. I started with very small amounts of extender and added in half-teaspoon increments until I got the best result. If you use too much extender, you will actually get sagging and pooling, even on horizontal surfaces. In the right porportion, however, I have found that the Polyacrylic will flow out and level better, dry more slowly, allowing for spot touch-ups, and produce a brilliant gloss. I rub out this finish starting with 600 grit wet/dry paper, moistening with diluted Behlen's Wool-Lube. I then proceed with 800, 1200, up to 3200 grit paper. Finally, I use pumice followed by rottenstone with mineral oil on a felt block. My customers love the results of this process. You can achieve a very high, deep gloss, or a satin finish by using a less stringent rub-out procedure. To add color to the otherwise clear Polyacrylic finish, I add an appropriate Trans-tint dye, diluted in water, to the Polyacrylic. Add color a little at a time, as the color deepenss with each application. Finish with at least one clear, uncolored coat. Sand with a high-grit paper or scotch brite pad between coats, clean very thoroughly after sanding. I also recommend straining the finish right out of the can. I have actually trapped small particles in my strainers. Use a high-quality synthetic brush, sturdy foam brush, or spray equipment. All stains and top coatings have a finite shelf life. For your "important" projects, invest in fresh finishing materials. It really makes a difference. Great finish, low odor, easy clean-up.

 

[PChristy]

Hi Renzo, thanks for he info and welcome to the site:icon_thum- When you get a chance go over to "Who We Are" and tell us a little bit about yourself and just to let you know everyone loves to see pictures

 

[Trent Mason]

Renzo,

That's quite a write up! I've never liked the results I've had with polyacrylics, but with this advice, they just may work. :icon_thum

 

[CrealBilly]

Renzo most excellent to have another professional finisher in the sawdust pile we call NCWW. I'm really glad your finding water based polyacrylic favorable. I really like the stuff myself but I think a lot of folks are hesitant to jump ship. It's nice to have a finish that 'works' without all the chemicals involved with other types of finishes and cleanup is a breeze. Personally I think it's a great finish and will catch on in time.

 

[sapwood]

Heck of a first post, Rev Renzo :icon_thum
Please stop by the Who We Are forum and introduce yourself.
Great to have a member from Ruff'ton :mrgreen:
I grew up in Caroleen!

Regards,
Roger

 

[Travis Porter]

Is there that much difference between the polycrilics, wb lacquers, wb polyurethanes? They all seem VERY similar to me in how they work.

 

[RevRenzo]

Re: wb lacquer and polyurethane. May I suggest you follow this link to a very good discussion of the use of water based lacquer and the challenges that it presents. Being a very small shop myself, I have found that using polyacrylic is the easiest and most effective waterborne alternative. I always encourage trying other materials, but for my customer's work, I mostly apply polyacrylic, Only if necessary, do I apply an oil or solvent based finish. Hope this is helpful. http://www.woodweb.com/knowledge_base/Waterbased_lacquer_for_small_shops.html