For more details regarding preparation, supplies, work area tips, etc. visit our Preparation page.
All surfaces should be clean and free from all dirt and oils.
Do NOT start sanding with very fine sandpaper on unfinished wood. Sanding is a progressive procedure. Prepare the surface by using medium sand paper first, and then proceed to finer grades. Water based finishes need a smoother surface than oil based finishes, but do not over sand or you may seal the wood so much that it will not take a finish. Sand raw wood in the direction of the grain starting with a coarser grit sand paper such as #120 sandpaper, and finish the final sanding with a finer grit sandpaper such as #220. End-grains (areas where the wood has been cut against the grain), such as the front side of a table, tend to soak up more stain than other surfaces. Give end-grain areas an additional sanding to control the absorption of stain. Refer to our sanding tutorial for more information.
We recommend minimizing the grain raise, especially on hardwoods such as Oak and Ash.Before applying the finish, spray the project with water or rub down with a damp cloth. Allow the wood to dry and then sand lightly to remove the raised grain. This conditions the wood to accept water based finishes.
Option: Soft woods such as Pine and Aspen absorb stain at an uneven rate and may respond better to staining if the wood bas been pre-sealed. A natural (clear) stain can be applied to raw wood to condition the surface for uniform penetration of the stain. Pre-sealing will cause the final stain to be lighter. Always test your color on a hidden part of the furniture! Allow the natural stain to dry 1 hour before applying your final stain color.
Unfinished furniture comes sanded from the factory, but still needs the final sanding with #180 or #220 sandpaper.
Remove dust with an air hose, damp cloth or “oil free” tack cloths. Do not use oil based tack cloths when using water based finish. Most tack cloths contain oil and will contaminate the surface.
On woods such as oak and ash, pre-wet the wood with a damp cloth to raise the grain before final sanding. Allow the dampened wood to dry 30 minutes before the final sanding. This will provide a smoother final finish.
Do NOT use steel wool when preparing wood for water based finish, as steel particles will cause rust spots.
Spray Application of Water Based Top Coats
Water Based Top Coats are ready to spray from the container. Thinning is not necessary. However, in hot climates, an extender can be used to increase the open time.
Water Based PolyAcrylic can be sprayed with HVLP systems or conventional sprayers. If you are using a sprayer that has been used for oil based or lacquers, clean the unit thoroughly and rinse with warm water before using. Apply a thin coat first that will dry and harden faster. Sand this first coat down to a smooth base on which to build your finish coats. With water based finishes it is better to spray 2 thin coats rather than 1 heavy coat.
Practice makes perfect! If you have never sprayed finishes before, take a large piece of cardboard and practice your technique first. Spray water on the cardboard to learn how the gun works. Check your fluid settings and adjust the controls to get comfortable with the spray angles and to develop your technique.
Keep your gun at a 90* angle, 6-8" from the surface. On large flat areas, use wet, even patterns 6 to 8’ wide. Over lap each pass 25% to conceal lines. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray. Break your work into sections such as dresser top or drawer fronts. Spraying too large of an area can result in a textured grainy surface. A correctly sprayed finish should appear even and glossy. It is important to spray enough material to allow proper flow and leveling of the finish.
Trouble Shooting Guide for Spraying Water Based Top Coats
Rough, dry surface. This is called dry spray. You may have sprayed too lightly. Re-sand the finish with #320 paper and apply a heavier coat. Keep your gun at 6-8" from the surface.
Dimples in the finish. This is called orange peel, caused by spraying in temperatures that are too cool. Cooler temperatures will adversely affect how the finish will level and harden. Water based finishes must be applied at temperatures above 65 F. If it is cold enough to wear a sweater it is too cold to apply a water based finish. The surface of the wood must also be warm. If you turn the heat on when you enter your shop in the morning, the air heats up quickly but your furniture will still be cold for some time. Check the surface to see if it is warm. Also, check the temperature of the finish. Warming cold finish by setting the can next to a heater or setting the container in some hot water for 5 minutes will improve the ease of application. Note: Larger dimples are called "fish-eyes" or "craters". Cool temperatures can cause these, but the more likely source is contamination of the finish with either wax or silicone.
Blush. Blush, the term for a cloudy, milky appearance in the finish, has two causes. The most common reason is incompatible stain. For example, using a water based top coat over a heavy oil based stain. When the top coat is applied, the oil in the stain seeps up through the finish and reacts with the acrylic causing a chemical blush. To prevent this, use a quick drying water based stain. If you choose to use oil based stain, seal the stain with a coat of shellac or lacquer sealer. This will provide a barrier between the oil and the acrylic. Proper drying time between the oil stain and finish coats is essential! The other cause for blushing is high humidity. Spraying water based finish in humidities of over 75% may cause blushing because moisture becomes trapped beneath the finish and cannot evaporate. You can prevent this condition by increasing air movement in the finishing area with a fan. All water needs to evaporate is sufficient air movement. You can also improve drying conditions by increasing the temperature in the drying area.
Surface is not leveling out. In hot temperatures (85F – 100F) the finish may dry too fast. Use an Extender to open (increase) the dry time. Finishes that dry too fast may not completely level out before all the water evaporates from the finish. High humidity can cause the finishes to take longer to dry but will not harm the final finish.
