Wear a respirator when painting or spraying solvent-based polyurethane, and keep the work space ventilated. However, it is now January and all around the floor you can start to see separation between the polyurethane and each plank joint. Warning: Skip this step and the top can twist, cup or warp. This is a problem that happens most often with waterborne finishes in which the finish glues the sides of the boards together. The next day we looked at the floors and were not happy. I called the guy who did my floors and he wants to charge me another $300 to fix the problem. For more related content, subscribe to … These defects can appear when you spread a thick coat on a hot day and it dries too quickly. I waited 48 hours for the stain to dry before applying the 2 coats of poly. The table and the finish need to be kept at room temp. If the poly is water-based and too thick, thin it … Sorry. Q: We have Brazilian Cherry floors and had an experienced flooring guy screen/sand half of our floors. These are the TWO requirements needed for a polyurethane to cure. While a thicker coat of polyurethane affords better protection, it’s important to realize that thickness is built in layers. I guess that tells you what you need to do. 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. Though frustrating, it is not strange to see that your polyurethane finish does not dry several hours or days after application. Can polyurethane floor finish problems resolve themselves? Then try brushing it on scrap wood. Use mineral spirits if applying a solvent-based product and water for a water-based one. If you discover a major problem after the finish skins over … Flexible plastics are also made from polyurethane. A: I don’t believe there is any truth to that. Besides bubbles, possible problems include checks, cracks, runs or separation and blushing. 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. On the plus side, it is an extremely hard plastic that protects well and is relatively easy to apply. I need to make it look uniform. Always lightly sand an existing coat before applying a fresh one over it. 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. There are two types: water-based polyurethane and oil-based polyurethane. Unlike lacquer, polyurethane doesn't redissolve after it hardens, so problems should be resolved on a coat-by-coat basis. I doubt there’s any problem in finishing more frustrating than fish eye. 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 … 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. It's not an uncommon problem, especially when applying polyurethane as the finishing coats. A: Was this a waterborne polyurethane? The problem usually appears as moonlike craters in the first coat of finish seconds after application, but it can also appear as ridges (sometimes called “crawling”), and it can hold off showing itself until the second or third coat. Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Bubbling, puddling and running are common problems. Note: I just don’t care if there are a few fingerprints. Sand a checked or cracked finish with 220-grit sandpaper and recoat it. As a landscape builder, he helped establish two gardening companies. 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. Problems are difficult to predict, but there are three measures you can take to minimize your risk: Make sure the surface is clean. 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. This is generally just a matter of a few hours. 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. 4 steps to a perfect polyurethane finish. Now the floor looks very dull and chalky. I am having problems with my water based poly "cratering". I have never seen this happen before. If the polyurethane has crud in it, try filtering it through cheesecloth. 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. Check the remaining material to make sure it's clear and particle-free. He applied a very fast drying, oil-based polyurethane, clean satin finish. Make sure the surface is dull. Then over several hours or overnight it dries to walk on and over several weeks continues to cure, which means it keeps getting harder. However, brushing spar urethane is a hardworking job because it tends to harden faster, and will produce as result visible brush lines After removing the finish, give the wood ample time to dry before you recoat. 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. 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. The next day we looked at the floors and were not happy. If you experience oil-based polyurethane not drying well, it’s not likely that it’s bad polyurethane. This ensures adhesion and improves the overall finish. Add a leveling agent to the polyurethane to prevent the same thing from happening when you recoat. In all my videos on finish coating my number one rule is “LAY IT ON THIN”. 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. Let's start with polyurethane, a hardwood floor finish that's been popular in the US for the last 30 to 40 years. So for a truly professional looking finish multiple thin coats of polyurethane is … Here are the details: Sugar maple boards, sanded to 120 grit. The rough grain is dull, while the closed (smoother) areas are shiny. finish before it has a chance to evaporate. The finish will not hold up to … I keep my spray room about 65 degrees and the humidity is around 50%. 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. As Paint Source notes, polyurethane floor finishes are prone to visible scratches and other blemishes, which could require that you add more layers. It sounds…, We refinished our floors in September and they came out pretty nice. This can also be another cause of bubble. Wait for drips to dry before you scrape them off with a razor blade or sand them down with 220-grit sandpaper and recoat. 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. Do you have problems with your polyurethane being streaky or foggy when you brush it on? Any thoughts? In both cases we’re talking only about the first coat of polyurethane. If it goes on fine, use it. Q: We have Brazilian Cherry floors and had an experienced flooring guy screen/sand half of our floors. Minwax fast drying polyurethane problem. 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. Polyurethane is the most durable of clear exterior finishes. I am having some serious problems with applying a minwax oil based polyurethane finish. To save drying time, coat the bottom and then immediately flip it over to finish the top. How to Clean Your A/C / Air Conditioner Condenser Unit – A clean air conditioner saves $! Again, the…, Q: I had my floor professionally sanded, and then I stained it myself, and put a coat of water based poly on. Jump to Latest Follow 1 - 2 of 2 Posts. Basically, the polyurethane is pulling away from the floor where each plank meets. Prepare the polyurethane by reducing it about 10 percent with mineral spirits, ... How to get consistent stain on problem woods. After the f As a clear finish for woodwork, polyurethane has advantages over lacquer and alkyd varnish, but it also has disadvantages. I am a flooring contractor, so I do have the equipment. This is why leveling is the pre-buffing step required next. I just found out from MinWax they have a problem with their stain and polyurethane. While layers of polyurethane can protect underlying surfaces, they cannot protect themselves. I've been a lurker for a while but I'm having an issue with a recent project. Avoid using a finish that contains a solvent that could attack the existing coating. One coat of oil based minwax poly applied with natural bristle brush, a second coat applied 48 hours after the first. They can be caused by the turbulence of the paintbrush or by moisture released by the substrate. 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. Polyurethane finish on hardwood floors problem. Polyurethane is also used in the manufacture of water vessels like the construction of inflatable boats, sealants for boat decks and outdoor marine vessels, and as foam in rigid-hulled boats because it provides buoyancy, sound proofing, and force. Many can be corrected by sanding and recoating. A: Well, of course the open grain,…. 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. https://www.popularwoodworking.com/editors-blog/the_7_myths_of 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. This can cause problems if you apply the wrong type of polyurethane. ... Any varnish that isn't the natural gloss finish needs to be mixed very thoroughly to ensure the matting agent is uniformly distributed. Most every painter has experienced the problems of bubbles in polyurethane finishes. It had little round spots all over it that the polyurethane did not cover. Finish Both Sides at Once. This defect, called blushing, is the result of moisture in the wood and is more likely occur when using a solvent-based product. I am using a Bink's hvlp, top of the line, spray system. What can I use on it or how can I repair it? Pop bubbles that appear when painting or spraying polyurethane with the tip of a paintbrush. 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. Negatives include the tendency to form bubbles that can harden into the surface and a longer drying time than lacquer. Both finish types come with a spray application. Polyurethane finish problems? Is this true, these polyurethane floor finish problems will solve themselves, or should I be calling my bank to stop payment? After flattening the affected area with sandpaper, wait until the temperature drops and spread a thinner coat. Remove the finish with an oscillating tool, a sanding accessory and 100-grit sandpaper if it turns cloudy after it hardens. Loose or Creaking Boards & Tight or Popping Boards, recommendation to hire an experienced pro. 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. 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. Uncured polyurethane can cause breathing problems such as asthma. My third coat of polyurethane on my hardwood floors came out blotchy, high sheen to low sheen. Examine the remaining finish. 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. 90% of users apply polyurethane incorrectly. 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. How do we fix this? He applied a very fast drying, oil-based polyurethane, clean satin finish. With a solid wood top like this one, finish both the top and the bottom surfaces, even if the bottom won’t show. © Copyright 2020 Hearst Communications, Inc. The cratering is a little larger than … Cleanliness. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. (72 F) and at Relative Humidity (RH) of 35-65%. While there is no easy way to remove silicone from wood, you may be able to get most of it off by sanding. 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. 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. Less shine. I did the same…, Q: I had my hardwood sanded and refinished and high-gloss put on. Hence it is important to check the condition of hardener. This can be very important in some projects and it’s often a strong reason for choosing polyurethane … 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. Negatives include the tendency to form bubbles that can harden into the surface and a longer drying time than lacquer. If there is anyone who knows of something that I can do I would really appreciate the help. 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. 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. This defect is caused by silicone in the substrate which may have been left by furniture polish or wax. 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. 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. 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