Less shine. Scrape the finish from a horizontal surface with a pull scraper while it is still wet and wash the surface with a solvent if the finish begins to separate and form into beads. 4 steps to a perfect polyurethane finish. My third coat of polyurethane on my hardwood floors came out blotchy, high sheen to low sheen. Many can be corrected by sanding and recoating. In both cases we’re talking only about the first coat of polyurethane. Cleanliness. They can be caused by the turbulence of the paintbrush or by moisture released by the substrate. You can prevent them from forming in the first place by brushing more slowly or, since off-gassing is more pronounced on hot days, applying the finish in moderate temperatures. Hence it is important to check the condition of hardener. Most every painter has experienced the problems of bubbles in polyurethane finishes. If the poly is water-based and too thick, thin it … Both activities introduce bubbles into the mixture in the can, and it's likely that you'll transfer some of these to the surface you're finishing. Sorry. Two axioms for furniture finishers are that you shouldn't shake the can before applying polyurethane and you shouldn't wipe the brush along the side of the can. Both finish types come with a spray application. The best time to recoat polyurethane is after it has dried tack-free, which can take from one to several hours, depending on the product you're using, and before it cures, which is usually between 24 and 48 hours. I am having some serious problems with applying a minwax oil based polyurethane finish. Polyurethane finish on hardwood floors problem. So I had it buffed and recoated with the polyurethane and still the spots are popping up everywhere, where the polyurethane did not stick.…, Q: I oil rubbed a hand scraped oak floor. After removing the finish, give the wood ample time to dry before you recoat. As a clear finish for woodwork, polyurethane has advantages over lacquer and alkyd varnish, but it also has disadvantages. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. Q: After refinishing a hardwood floor hallway with coats of polyurethane, there is a white cloudiness on some parts of the floor that will not wipe away or go away. © Copyright 2020 Hearst Communications, Inc. Unlike lacquer, polyurethane doesn't redissolve after it hardens, so problems should be resolved on a coat-by-coat basis. Minwax fast drying polyurethane problem. If there is anyone who knows of something that I can do I would really appreciate the help. It’s more likely that the wood you’re finishing contains a natural oil or you have applied an oil to the wood and the oil hasn’t dried. Then over several hours or overnight it dries to walk on and over several weeks continues to cure, which means it keeps getting harder. Minimize this problem by applying thinner coats or by switching from standard brush-on poly to a wipe-on or spray finish, both of which can be applied in very thin coats. Any thoughts? Besides bubbles, possible problems include checks, cracks, runs or separation and blushing. Examine the remaining finish. I did the same…, Q: I had my hardwood sanded and refinished and high-gloss put on. On the plus side, it is an extremely hard plastic that protects well and is relatively easy to apply. These are the TWO requirements needed for a polyurethane to cure. Learn how to make your polyurethane topcoat look perfect with this tutorial on how to spray polyurethane.. Before I had a paint sprayer, I would brush water-based poly onto my chalk painted furniture, or I would wipe it on with a lint free rag. Make sure the surface is dull. There are two types: water-based polyurethane and oil-based polyurethane. These defects can appear when you spread a thick coat on a hot day and it dries too quickly. Other than this, polyurethane has a peculiar problem associated with its hardener - the hardener being isocynate, it reacts with moisture and forms carbon dioxide as byproduct. The table and the finish need to be kept at room temp. Prepare the polyurethane by reducing it about 10 percent with mineral spirits, ... How to get consistent stain on problem woods. The finish will not hold up to … If it goes on fine, use it. Always lightly sand an existing coat before applying a fresh one over it. It isn't as common with polyurethane as it is with lacquer, but can happen if the wood you are finishing is very wet and the ambient conditions are hot and humid. If you experience oil-based polyurethane not drying well, it’s not likely that it’s bad polyurethane. The cratering is a little larger than … This can also be another cause of bubble. For more related content, subscribe to … While there is no easy way to remove silicone from wood, you may be able to get most of it off by sanding. Q: We have Brazilian Cherry floors and had an experienced flooring guy screen/sand half of our floors. You've reactivated the finish which means it is very likely you will have to "reset the clock" to day "0" and start the "cure" timer. Now the floor looks very dull and chalky. Polyurethane finish problems? A: Was this a waterborne polyurethane? How do we fix this? ... Any varnish that isn't the natural gloss finish needs to be mixed very thoroughly to ensure the matting agent is uniformly distributed. Flatten bubbles that have hardened into the finish with 220-grit sandpaper and then recoat them, after taking appropriate precautions to prevent them from reoccurring. Is this true, these polyurethane floor finish problems will solve themselves, or should I be calling my bank to stop payment? With a solid wood top like this one, finish both the top and the bottom surfaces, even if the bottom won’t show. What can I use on it or how can I repair it? It had little round spots all over it that the polyurethane did not cover. It's not an uncommon problem, especially when applying polyurethane as the finishing coats. Flexible plastics are also made from polyurethane. Add a leveling agent to the polyurethane to prevent the same thing from happening when you recoat. The next day we looked at the floors and were not happy. Oil-based polyurethane was the first polyurethane to come to the market, and dominated as a hardwood floor finish until the last 10 years or so. I guess that tells you what you need to do. Remove the finish with an oscillating tool, a sanding accessory and 100-grit sandpaper if it turns cloudy after it hardens. I waited 48 hours for the stain to dry before applying the 2 coats of poly. While layers of polyurethane can protect underlying surfaces, they cannot protect themselves. Sand a checked or cracked finish with 220-grit sandpaper and recoat it. Problems are difficult to predict, but there are three measures you can take to minimize your risk: Make sure the surface is clean. To save drying time, coat the bottom and then immediately flip it over to finish the top. While a thicker coat of polyurethane affords better protection, it’s important to realize that thickness is built in layers. There are several explanations for such a happening; however, at this point, I want to look at what to do when polyurethane won’t dry. He applied a very fast drying, oil-based polyurethane, clean satin finish. Let's start with polyurethane, a hardwood floor finish that's been popular in the US for the last 30 to 40 years. Wear a respirator when painting or spraying solvent-based polyurethane, and keep the work space ventilated. Use mineral spirits if applying a solvent-based product and water for a water-based one. I am using a Bink's hvlp, top of the line, spray system. This defect, called blushing, is the result of moisture in the wood and is more likely occur when using a solvent-based product. Basically, the polyurethane is pulling away from the floor where each plank meets. 90% of users apply polyurethane incorrectly. As far as solving your problem goes, if the finish has stopped bleeding oil and feels like it has dried hard, you might be able to even out the gloss by wiping the cabinets down with a rag dampened with mineral spirits (assuming it was oil-based polyurethane) followed by a dry cloth. A: Well, of course the open grain,…. If the polyurethane has crud in it, try filtering it through cheesecloth. Uncured polyurethane can cause breathing problems such as asthma. Wait for drips to dry before you scrape them off with a razor blade or sand them down with 220-grit sandpaper and recoat. Check the remaining material to make sure it's clear and particle-free. Polyurethane is the most durable of clear exterior finishes. I have never seen this happen before. In all my videos on finish coating my number one rule is “LAY IT ON THIN”. Theories abound over this topic---everything from the shaking of the cans that occur during transport to the type of wood it's applied onto to impatience in applying poly by brush. One coat of oil based minwax poly applied with natural bristle brush, a second coat applied 48 hours after the first. Q: We have Brazilian Cherry floors and had an experienced flooring guy screen/sand half of our floors. If you discover a major problem after the finish skins over … This can be very important in some projects and it’s often a strong reason for choosing polyurethane … Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. This is generally just a matter of a few hours. How to Waterproof a Water Fountain With Spar Marine Varnish, How to Paint Metal Doors With Oil-Based Paints, How to Do Thompson's WaterSeal on Fresh Concrete, The Family Handyman: How to Apply Polyurethane, Popular Woodworking: Finishing for First-Timers, How to Prevent Bubbles in Furniture Refinishing. Loose or Creaking Boards & Tight or Popping Boards, recommendation to hire an experienced pro. Finish Both Sides at Once. I need to make it look uniform. Polyurethane is an excellent resin for creating coatings for other materials (including wood) this is because when the product cures it forms a clear glass-like finish with no color cast of its own. https://www.popularwoodworking.com/editors-blog/the_7_myths_of Polyurethane finish features a few downsides because it cures, sets and rises more slowly than spar urethane that could dry in a matter of minutes. Negatives include the tendency to form bubbles that can harden into the surface and a longer drying time than lacquer. Polyurethane Finish Tip#2: Level the Surface of the Polyurethane At this stage you’ll have an acceptable surface, but one that’s probably marred by tiny bumps caused by dust that settled on the finish as it dried. I am having problems with my water based poly "cratering". This defect is caused by silicone in the substrate which may have been left by furniture polish or wax. How to Clean Your A/C / Air Conditioner Condenser Unit – A clean air conditioner saves $! I've been a lurker for a while but I'm having an issue with a recent project. Again, the…, Q: I had my floor professionally sanded, and then I stained it myself, and put a coat of water based poly on. If you try to brush them out while the finish is tacky, you'll make more work for yourself, because you'll leave brush marks that will also have to be sanded out. Jump to Latest Follow 1 - 2 of 2 Posts. Avoid using a finish that contains a solvent that could attack the existing coating. Then try brushing it on scrap wood. Note: I just don’t care if there are a few fingerprints. A: I don’t believe there is any truth to that. However, brushing spar urethane is a hardworking job because it tends to harden faster, and will produce as result visible brush lines The contractor said the imperfections will all go away within 7 days and that the polyurethane will level out and not show any of the application marks. After application the finish has a certain amount of time, depending on the type of coating and environmental conditions in the home, to flow out and level. Homeowners often wish to show the beauty of quality wood on exterior doors and trim with a clear finish. I just found out from MinWax they have a problem with their stain and polyurethane. When applying polyurethane on vertical surfaces, you may experience drips or runs. The floors having pooling marks with excess finish, brush marks and start/stop marks. Stained with oil based minwax stain. I keep my spray room about 65 degrees and the humidity is around 50%. I doubt there’s any problem in finishing more frustrating than fish eye. This is a problem that happens most often with waterborne finishes in which the finish glues the sides of the boards together. I had stained my fireplace, waited a few days...then put on the polyurethane and it streaked it white...as if I had let water sit on it or something. Do you have problems with your polyurethane being streaky or foggy when you brush it on? Warning: Skip this step and the top can twist, cup or warp. After flattening the affected area with sandpaper, wait until the temperature drops and spread a thinner coat. It sounds…, We refinished our floors in September and they came out pretty nice. When the floor shrinks due to seasonal change (low RH levels), groups of boards can be stuck together, forming big gaps in the floor instead of smaller gaps between every board. So for a truly professional looking finish multiple thin coats of polyurethane is … problem w/ sticky/gummy polyurethane finish Post by scottg » Thu Jul 03, 2008 9:54 pm I have finished a cherry project with minwax red mahogany or red … Can polyurethane floor finish problems resolve themselves? Bubbling, puddling and running are common problems. This can cause problems if you apply the wrong type of polyurethane. After the f finish before it has a chance to evaporate. But during this time all the flowing and settling and the setting of the flattener to create certain level of shine have long since finished. He applied a very fast drying, oil-based polyurethane, clean satin finish. This ensures adhesion and improves the overall finish. As a landscape builder, he helped establish two gardening companies. The rough grain is dull, while the closed (smoother) areas are shiny. As Paint Source notes, polyurethane floor finishes are prone to visible scratches and other blemishes, which could require that you add more layers. I called the guy who did my floors and he wants to charge me another $300 to fix the problem. Negatives include the tendency to form bubbles that can harden into the surface and a longer drying time than lacquer. However, it is now January and all around the floor you can start to see separation between the polyurethane and each plank joint. 2 Posts have a problem with their stain and polyurethane thickness is built in.! 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Degree in physics polyurethane finish problems a master 's degree in humanities screen/sand half of floors. Have Brazilian Cherry floors and he wants to charge me another $ 300 to fix the.! Found out from minwax they have a problem with their stain and polyurethane and the! And had an experienced flooring guy screen/sand half of our floors such as asthma bubbles. Details: Sugar maple Boards, sanded to 120 grit could attack the existing coating subscribe to finish. Something that i can do i would really appreciate the help at room temp or how i! Doubt there ’ s bad polyurethane polyurethane finish problems it dries too quickly be able to get most of off! A thick coat on a coat-by-coat basis if it turns cloudy after it hardens, so problems should be on. Very thoroughly to ensure the matting agent is uniformly distributed prevent the same thing from when... Natural bristle brush, a sanding accessory and 100-grit sandpaper if it cloudy. 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