Strip off the Waterbased Finishing

Stripping off old finishes could be a tough job, but it is needed when we want to update our old finishes with a new look and color. The product must be clean and free from the old finish as an unfinished surface if we want to apply a new finishing process (with a new finishing process and material). We already posted an article about stripping off the old finish in our previous article: How to Strip off the old finish. In this article, we want to share about how to strip off the waterbase finishing layer at the wood finishing. Waterbased finishing materials, including the water-based stain, waterbase coating, water-based paint, latex paint, or wall paint, are quite commonly used in the furniture industry. They can be used alone or in combination in the wood furniture finishing. The full water-based finishing system is used to make the safe and environmentally friendly finishing system. While the water-based paint, latex paint, or wall paint is also much used in combination with solvent-base coating to make some special finishes.

Although water-based material uses water as solvent, when it is dry, it will cure hard and won’t be resolved with water anymore. You need a proper solvent to solve and break the paint layer. More over, the water-based paint is usually thick and hard; it has to be completely wetted to get removed easily. 

 

Here is the process of stripping the water-based finishing layer

Dampen rags (or sponges) with washing thinner and put them at the coating surface; let the thinner soak and wet the finishing layer. It needs some minutes to let the thinner wet, penetrate, and break the finishing layer. The thinner used has to be made of solvents with high solvability for the paint. Acetone or MEK are the good solvents to be used; they are strong enough to solve the paint or coating. But they both have a fast evaporation rate that could be too fast for the stripping process. You can add toluene and/or alcohol to the thinner mix to let it slowly dry.

The wet finishing layer will be broken, contracted, and chipped off. Use a knife to scrape a layer finishing that is already damaged. Do the scrapping carefully since it may cause the scratch to the wood surface. Use the plastic knife to minimize the risk of scratching. Continue the surface cleaning with dampened rag; a scotch brite can also be used to rub the rest of the paint. Although it has been detached from the wood surface, the water-based film layer will not be perfectly dissolved. The water-based coating particles may be left inside in the pores and grain of wood. You can use a wire brush to clean the particles inside the wood pores and grains.

If there was a wood stain at the finishing, then there may be some color at the wood. The stain is absorbed and will change the color of the wood and cannot be cleaned with thinner. You can go ahead and apply the new finishing process in this condition as long as the new finishing color can be made based on the wood color. But if the new finishing color is lighter than the wood color now, then you have to resand the wood surface. Use the # 180 sandpaper to sand the wood surface evenly. Make sure you got the smooth and even wood surface before start to do the refinishing process.