1 Dec 2011
There are different types of polyurethane finishes. These may be water based or oil based. You can have different paint finishes like semi-gloss, high-gloss or satin finish. This plastic based resin can be applied on many materials including fiberglass, fabrics, metals and plastics. However, it’s most frequently used for wooden materials. The idea of applying polyurethane finish is to enhance the life of different items, as it can resist water and chemicals including gasoline. Since it comes in many forms, it’s important to read the instructions of the manufacturer to assess if it is a polyurethane floor finish or meant for external polyurethane finish.
Solvent Based Finish
The working of solvent based and water based polyurethane is different. The chemical reaction that takes place bonds the polymers so strongly that even mineral spirits fail to take away the finish from the surface after the process has been completed. A very important precaution that needs to be taken when working with solvent based polyurethane is to ensure that the working area is adequately ventilated. That is to save you from the harmful fumes emitted from the surface of the furniture.
Water Based Finish
Though the water based polyurethane finish dries fast and is easier to clean, the work should still be carried in a well ventilated area as there is emission of fumes, though milder in nature. One must use safety gear like safety goggles and mask while staining wooden furniture or hardwood floors with polyurethane finish to prevent the skin from getting in contact with the finish. Fabric or paper mask are unable to filter the fumes and should not be used for the purpose. Since polyurethane finish is highly flammable, it should not be applied close to a furnace or exposed flame.
You can procure polyurethane finish in buckets as also in spray cans. Further, you may have it as a clear topcoat or in numerous colors. Spray cans of polyurethane finish are available at most hobby shops. The product sold in can is already mixed and ready to use. Polyurethane finish is hard thick and glossy, quite like car finish. It’s perfect for making models because it delivers a perfect glossy finish and can resist many fluids. For that reason it’s perfect for refinishing of furniture too.
How To Use Polyurethane Finish
The critical factor for staining of wood is its proper preparation. If polyurethane finish is to be used for large projects, it is important to mix the finish and the catalyst properly; else the final finish may develop bubbles or cracks after use. When used for finishing fresh wooden surfaces for the first time or for refinishing hardwood floors, the surface should be thoroughly cleaned before hand. Here are some helpful tips for application of polyurethane finishes for hardwood floors or other such large wooden areas.
The first step is to sand the wood, followed by cleaning with a vacuum cleaner. Then, wipe the surface clean with a lint-free cloth. Make sure that there is no dust or debris on the surface. Next, you apply a thin coat of the finish and let it get cured. The curing time for water based polyurethane finish is about one hour, whereas it takes four hours for the solvent based variety to get dried up. When working in humid areas, the drying time increases. Once again, clean the surface and apply another coat of polyurethane finish. Let the coat get cured. You should understand that applying a number of thinner coats gives far better results than applying a few thicker coats. It’s important that you sand and clean at the end of each application of coat.
So, that’s all you need to know about polyurethane finish. You can procure tinted or clear variety of polyurethane finish in bucket or can. See that the surface is well prepared before application of the finish to get a silky glossy finish of wooden items.