Fine Points of Paint Finishes
More expensive acrylics typically perform better than "latex" formulas. Here are some tips on choosing and applying opaque finishes. July 3, 2008
Question
I have been getting more and more requests from a large client of mine for painted work. I generally use a tung oil/poly rubbing finish on my furniture work. The painted work would, of course, be "high end."
I won't be using lacquer or CV due to fire concerns, disposal, and local permitting. I plan on getting a 4 stage Fuji turbine with the non-bleeder gun. For colored work I am planning on spraying a shellac sanding coat, then spraying high quality latex for the color (thinning about 15% and using Flotrol). I have some question about a topcoat. I am thinking of using either thinned WB polyurethane, or WB lacquer (ML Campbell). Will the latex need a topcoat? Will the latex be too thick for fine details and molding? Is it easy to touch up?
This work would represent about 25% of my work per year, so I would only be spraying occasionally. Let me know what you think about my plan!
Forum Responses
(Finishing Forum)
From contributor S:
You will have much better results using WB primer and lacquer versus your latex low end system. If ML Campbell is available to you, use their Polystar primer and Polystar pigmented lacquer. You should not have to clear coat unless you're doing some distressing or glazing.
From the original questioner:
I can get the primer and the clear coat, but not the custom color matching I will need. Believe me, I would much rather spray that than latex.
From contributor C:
You would be better off using Zinnser shellac primer if you're going with latex over it. This will give you an opaque surface for the latex and bonds just as well as clear shellac. I don't use a non-bleeder gun, so someone else will have to answer that. With a bleeder gun, it is sufficient to only thin 5 to 10% depending on the brand of latex chosen (use a premium brand since your client is willing to pay big money). The Flowtrol should not be necessary, but you can use if you need. After the latex I would use an acrylic - either solvent (my choice) or, if you prefer, water. In this way you will get no yellowing. You can get by without a clear coat only if the product is formulated to withstand heavy use and the easy cleaning type, but having to clear coat there gives more protection for sure and makes cleaning easier than the latex alone.
From contributor S:
You must have a local paint store. Most will have Degussa (Huls) colorants 896 series. Have them tint it for you. Slip them a couple of bucks and I'm sure they will help you out.
From contributor A:
Zinssers is fine. WB lacquer... eh, okay - better than latex? My druthers would be 100% acrylic if you can't get color lacquer.
Contributor C, you use the terms "acrylic" and "latex" as if they are the same, or am I not understanding something?
From contributor C:
Very compatible, but not quite the same chemistry. Latex is an emulsion base acrylic usually manufactured for a base for industrial and commercial use that is normally pigmented by the coatings companies formulating the end product. It is purchased by SW, BM, etc. in this condition and all the other additives and pigments, etc added to finish off the product lines requirements. There are many starting latex emulsions available for this purpose. Clear acrylic coatings are made generally in two types - water emulsion and solvent base. Both chemistries are different even though both can be made as or into enamels. Suffice to say - if you tried using the base latex paint emulsion by itself as a clear coat for wood, the results will be quite different than ones formulated for wood coatings. You would not be happy with the results.
From contributor M:
Get the MLC Polystar if it's available. My distributor will color match to any major paint manufacturer's colors. Otherwise Sherwin Williams ProClassic is decent as well as Muralo's Ultra. These are both waterborne acrylic topcoats. Both can be tinted in the store. Both spray very well with little fuss.
From contributor Y:
I second the Proclassic from SW. Just reduce a little and it sprays very well, just doesn't dry as fast as lacquer.
From contributor B:
This is a no-brainer. First off, don't use latex! Bad move, dries too slow. I use General Finish's WB white undercoat/SS and have my local paint shop tint them for me. I shoot a couple of coats to get my color right, then shoot a couple of clear coats. Case closed. Dyno finish. You could also use GF's white poly or lacquer and have your local paint shop tint it for you (they all use the same WB UTCs) or you could have GF tint it for you. They have numerous colors on file and can custom match if you supply the sample. I've use this method on several high-end kitchens and furniture projects with great results.
From contributor C:
When you're going by a commercial latex brand, look for those with the highest amounts of true acrylics - ethyl/methyl acrylates. Not necessarily by manufacturer. Latex - the product of the rubber tree - is not contained in commercial paints labeled "latex". This has just become a common name for a series of synthetic polymers used in their formulation. PVAs, vinyl acrylic, etc. Though the can may state it's 100% acrylic, that does not mean it is 100% methyl or ethyl acrylate (true acrylic) - these are much more expensive to use than other lesser acrylates, and a softer and less durable finish results in a typical formulation of 70 or 80% vinyl styrene and only 20 or 30% of the true acrylic polymer. PVAs are also used, which make the film softer, also like the vinyls. The manufacturer and their outlets normally won't tell you that a paint that is designated 100% acrylic only means they are a mixture of 2 to 4 acrylic type of resins. The best way to tell if you have an inferior acrylic latex paint is, after it dries, to splash water on it and see if it goes a couple of shades lighter than the dry areas. If it does, you'll know it's made with a good degree of vinyl and possibly PVA and only a small portion of true acrylic resin. Also the cost will help you out - if it's twice as much as their next base paint, it will most likely be because the true acrylates are being used in larger quantities. The more true acrylates in the paint the better all the good qualities of the true acrylates will be - better adhesion, hold out, cleanability, gloss retention, etc. Since there in no actual latex in the paint, you can also ensure any customer that asks because of latex allergies, that yours does not contain any. You'll find in using true acrylate paints (just like with what you're using as waterbase clear coats), the more it contains, the better the end results.
From contributor M:
I concur with most of contributor C's description. At the end of the day, latex (no latex glues in the solution) paints are meant for walls. They are not designed for painting cabinetry. They do a poor job of painting interior trim in houses. Often the newer paints - ProClassic, Ultra, BJ WB Impervo (I believe) - are 100% acrylic. The professional types often mix poly in with the acrylics. As contributor C stated, latex describes a type of chemistry rather than the rubbery stuff from trees. In my experience there is no additive that keeps latex from spraying like fluff. It needs to be topcoated for durability.
From contributor U:
DSI in Nashville carries ML Campbell and can color match for you. When spraying something new, I prefer to use one company's line rather than mixing and matching.
From the original questioner:
DSI matches the Magnamax, but not the Polystar. "We don't do much volume in waterborne," quote the rep. He did say it needed glycol based colorants. Is that something the paint store could handle?
From contributor E:
There are two more ideas I didn't see posted. One is Target's USL lacquer. It can be tinted at any local paint store for custom matching. The other is good old fashioned milk paint. Ask any refinisher about how durable it is.
