“If a true water-based finish line is produced correctly, every ingredient used in the manufacturing will be dispersible in plain water.”
Water-based finishes have been around for many years. Much like the latex house paints of years gone by, they have been undergoing constant changes and improvements. Several years ago, any self-respecting painting contractor would only use the old oil-based paints with linseed oil primers. But, in today's commercial house painting industry, almost no one is using these oil-based products. Painting contractors have switched to the highly improved water-based products. Indeed, water-based products have largely taken over that market. In addition to being low in VOCs (volatile organic compounds), the water-based products dry many times faster that the "oils,” so the surface won’t be ruined if it rains the next day.
You can make similar comparison with interior house paints. The old latex wall and ceiling paints are being replaced by the new generation of acrylic and polyurethane water-based paints and varnishes and topcoats.
A Little Bit of History
Woodworkers and other finishers had a hard time with most of the original water-based finishes. The original clear water-based finishes were based on the older latex formulations and gradually progressed into the "PVA" technology and chemistry. PVA is a colorless resin used in adhesive and paint technology and chemistry. Simply speaking, the original manufacturers of water-based clear coats and varnishes were making their products out of the same materials as commercial wood glues. It’s comparable to when you have a run or drip of glue on a wood surface that you want to stain or finish. You are left with an area that does not accept the stain because the glue/ finish spot shows up as a light area.
Manufacturing the Highest Quality Water-Based Products
In the last few years most major American finish manufacturers have moved to formulas that have been used in Europe for many years and are only now working their way into the USA manufacturing sector. This is especially evident with manufacturers who have been making water-based products for 20 years or more, and even more prominent with companies that exclusively manufacture only water-based materials. Their livelihood and very existence is dependent upon their products being equal or superior to the currently available solvent and oil products.
Water Based Coating Recipe
Manufacturing the finest water-based finishes can be compared to fine gourmet cooking. If you don't use the best ingredients available and take meticulous care in preparation and cooking, you will fall short in the final results. Almost anyone can prepare an adequate meal and by the same token almost any finish manufacturing company can make a workable water-based coating.
What separates out the best from the rest is selecting top quality raw ingredients and resins (both monomers and polymers) available. These products (liquid acrylics and polyurethanes) are the building blocks of any and all quality finishes. Like cooking, if you choose a generic cut of meat or low quality veggies, they will affect the final taste of your meal. You don't make filet mignon out of chuck steak.
After selecting these fine raw materials you must blend them in a meticulous and tightly controlled fashion. If the co-solvents, surfactants, wetting agents, de-foamers, surface tension modifiers, flatting compounds, self cross-linkers, etc., are not added in critical, specific fashion, the final results will be much like the old school water-reducible coatings that have been available at big box stores and hobby stores for the past several years. If a true water-based finish line is produced correctly, every ingredient used in the manufacturing will be dispersible in plain water. This would mean everything in a company's complete line of finishes could be inter-mixed together. For example, you should be able to add stains to topcoats, to make shading or toning finish, or a sprayable glaze. You may also add water to topcoats and to gel stains to make a glaze, clear, or colored grain filler.
It is our experience that the products these producers have available are not found in your larger big box stores but are instead offered online from many of the major woodwork suppliers and through retail stores and catalog companies that cater to the professional woodworker. It is also very valuable to get these products from a supplier who also carries professional quality finishing supplies such as brushes and high quality spray equipment that has been engineered specifically for the new high-tech water-base coatings.
Putting It On with Split Ends
If you choose to finish by hand, the switch to water-base is extremely easy. The stains can be simply brushed or wiped on the wood with a micro fiber cloth or an inexpensive foam brush. For topcoats, most manufacturers have some version of a wiping or brushable polyurethane varnish. For topcoats, the quality of the brush is extremely critical to the final outcome of the finish. A foam brush will provide unsatisfactory results when applying topcoats. Foam brushes will incorporate small imperfections and cause bubbles or foam in the final topcoats. We recommend a high quality "synthetic bristle” brush, designed specifically for applying the new generation of water-based finishes. They are available in most good paint stores and better retail stores. Choose the brush with the finest bristles available. Take a close look at the individual strands in the brush. Pay particular attention to the very ends of the bristles. If they appear to have "split ends" (an undesirable occurrence in your hair) the brush will perform much better than a coarser, flat or straight cut strand.
The Best Way to Spray
If you are planning on spraying the water-based products, or are thinking about exploring the possibilities of spraying, these new water-based finishes are just what the doctor ordered. With dramatic improvements in spray technology over the past few years, it has become easier to spray a high-end professional looking finish than ever before. Water-based coatings offer obvious benefits including being non-flammable, non-combustible, with low odor and water clean up. So even the occasional woodworker, novice finisher, or hobbyist can spray finishes in shops or woodworking areas of their homes. This is especially true of the new generation of HVLP Sprayers. These are available for use with either a standard air compressor, or my favorite, the turbine powered systems. These are a total unit that simply requires a standard 110-volt electrical outlet. You just plug in the unit, add you stain or finish, pull the trigger of the spray gun and you’ll be applying the same quality finish that the high-end furniture factories and professional cabinetmakers are achieving.
It takes only a couple of tries on a small project or scrap wood samples to see that you can achieve these fantastic results at home or in your shop, without the necessity of a large or very expensive spray booth. We do recommend that you attempt a couple of smaller projects or samples before you attempt finishing your grand piano or dining room table. As with anything, it is important walk before you run or get your feet wet, before jumping into the deep end!
As you proceed with your water-based endeavors we would highly recommend that you purchase all of your finishing products from a supplier that carries everything that you will need for your complete project, from start to finish. Pun intended! This includes your sand paper, brushes, stains, finishes, and especially your spray equipment. Suppliers have invested time and money to do research and development of the complete package of supplies you will need to get the results you desire. This will make your finishing experience a joy and not a dreaded task. You will achieve the professional, high quality results that your woodworking projects deserve.
George Cash is a leading water-base finish developer, a guest speaker at The Woodworking Shows, and lectures on the national standard for environmental and safety management. He devised a finishing process for a leading toy manufacturer to comply with all of the newer and more restrictive US Standards for children’s toys and furniture, and received a Wisconsin Governor’s Award for his work in reducing hazardous waste.