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