{"id":8018,"date":"2025-01-19T09:13:17","date_gmt":"2025-01-19T09:13:17","guid":{"rendered":"https:\/\/www.inthacity.com\/blog\/uncategorized\/5-reasons-polyurethane-finish-bumpy-how-minwax-fixes-it\/"},"modified":"2025-08-23T19:55:14","modified_gmt":"2025-08-24T00:55:14","slug":"5-reasons-polyurethane-finish-bumpy-how-minwax-fixes-it","status":"publish","type":"post","link":"https:\/\/www.inthacity.com\/blog\/life\/crafts\/woodworking\/5-reasons-polyurethane-finish-bumpy-how-minwax-fixes-it\/","title":{"rendered":"5 Reasons Why Your Polyurethane Finish is Bumpy and How Minwax Can Help Fix It"},"content":{"rendered":"<p>Ever noticed that when you show off a woodworking project, the first thing people do is touch it? It\u2019s like they\u2019re trying to <em>feel<\/em> your craftsmanship. According to James Hamilton, the mastermind behind the popular woodworking channel <a href=\"https:\/\/www.youtube.com\/channel\/UCstwpLSByklww1YojZN-KiQ\" title=\"Stumpy Nubs on YouTube\">Stumpy Nubs<\/a>, this is because humans are wired to experience the world through touch as much as sight. And let\u2019s face it, after pouring your heart, soul, and hard-earned cash into a project, the last thing you want is for someone\u2019s first impression to be ruined by a rough, bumpy finish. That\u2019s why sanding between coats of finish is an absolute game-changer. Today, we\u2019re diving deep into Stumpy Nubs\u2019 method for perfecting your wood finishes\u2014whether it\u2019s polyurethane, lacquer, or shellac.<\/p>\n<h2>Why Sanding Between Coats Matters<\/h2>\n<p>So, you\u2019ve applied your first coat of finish, and suddenly, that silky-smooth surface feels rough again. What gives? Two things likely happened: dust particles from the air settled onto the wet finish, or the wood fibers soaked up the finish and swelled. Yes, wood can be as dramatic as a reality TV star. Stumpy Nubs explains that while you can minimize swollen fibers by raising the grain before the first coat (check out his sanding tutorial for that), dust nibs are pretty much unavoidable. Even if you\u2019ve got a dedicated, dust-free finishing room, those pesky particles will find a way. The solution? Sanding between coats\u2014but not just any sanding. You need to do it right. And that\u2019s where this guide comes in.<\/p>\n<h3>The Tools You\u2019ll Need<\/h3>\n<p>Before we get into the nitty-gritty, let\u2019s talk about the tools. Stumpy Nubs recommends starting with 320-grit sandpaper for the first coat and then moving up to 600-grit for subsequent coats. Here\u2019s a quick <a href=\"https:\/\/amzn.to\/3FR24Dj\" title=\"shopping\">shopping<\/a> list to get you started:<\/p>\n<ul>\n<li><a href=\"https:\/\/amzn.to\/3Z4o9Jg\" title=\"320-grit sandpaper on Amazon\">320-grit sandpaper<\/a><\/li>\n<li><a href=\"https:\/\/amzn.to\/3Z4o9Jg\" title=\"600-grit sandpaper on Amazon\">600-grit sandpaper<\/a><\/li>\n<li>Mineral spirits, denatured alcohol, or water for wiping down surfaces<\/li>\n<li>A vacuum to clean up dust<\/li>\n<\/ul>\n<p>And don\u2019t forget those <a href=\"https:\/\/amzn.to\/3Z4o9Jg\" title=\"Isotunes Bluetooth Earbuds on Amazon\">Isotunes Bluetooth earbuds<\/a>\u2014because who doesn\u2019t want hearing protection and your favorite tunes while you work?<\/p>\n<h2>Step-by-Step Guide to Sanding Between Coats<\/h2>\n<p>Ready to transform your woodworking projects from \u201cmeh\u201d to \u201cmagnificent\u201d? Here\u2019s how Stumpy Nubs suggests sanding between coats of finish:<\/p>\n<h3>Step 1: Sand the First Coat<\/h3>\n<p>After applying the first coat of finish, let it dry completely. Then, grab your 320-grit sandpaper and sand the surface by hand. Use light pressure\u2014don\u2019t go all Hulk on it. Your goal here is to smooth out any swollen wood fibers or dust nibs without sanding off the entire coat. If your sandpaper gets gummy, give the finish more time to dry. You should see fine white dust, not sticky boogers of half-dried finish.<\/p>\n<p>Pro Tip: Use both hands\u2014one to move the sandpaper and the other to feel for imperfections. You\u2019re basically a wood whisperer at this point.<\/p>\n<h3>Step 2: Clean Up the Dust<\/h3>\n<p>Once you\u2019re done sanding, it\u2019s time to clean up. Don\u2019t use compressed air\u2014you\u2019ll just blow the dust around, and it\u2019ll settle right back onto your next coat. Instead, use a vacuum to suck up the dust, followed by a wipe-down with mineral spirits, denatured alcohol, or water. Just don\u2019t go overboard with the water\u2014unless you want to reawaken those dramatic wood fibers.<\/p>\n<h3>Step 3: Apply and Sand Subsequent Coats<\/h3>\n<p>After the second coat of finish, dust nibs are still your enemy, but swollen fibers should be less of an issue. Switch to 600-grit sandpaper and repeat the process. By now, you\u2019re probably noticing that thinner coats dry faster, which means less time for dust to settle. Efficiency, baby!<\/p>\n<p>Want to know a secret? Stumpy Nubs often switches to a brown paper bag for the final coat. Yes, a brown paper bag. It\u2019s cheaper than high-grit sandpaper and can make your finish as smooth as glass. Try it. You\u2019ll thank me later.<\/p>\n<h3>Step 4: The Final Coat<\/h3>\n<p>For the final coat, patience is key. Give it at least 24 hours to dry\u2014maybe even a few days. Then, use 1000 to 1500-grit sandpaper or that magical brown paper bag to buff out any last imperfections. By now, your project should feel like something you\u2019d proudly display in a museum. Or at least at <a href=\"https:\/\/www.inthacity.com\/blog\/newsletter\/\" title=\"iNthacity Community\">iNthacity: the Shining City on the Web<\/a>.<\/p>\n<h2>Why Timing Matters Between Coats<\/h2>\n<p>Here\u2019s something you might not have considered: finishes shrink as they dry. Some more than others, but they all do it. This can cause the finish to pucker on the surface, creating tiny bumps you can\u2019t always see but can definitely feel. The solution? Light sanding with 600-grit sandpaper. And if you\u2019re using oil-based polyurethane or shellac, timing is everything. These finishes can take weeks to fully cure, so the longer you wait between coats, the smoother your next coat will be.<\/p>\n<h2>Final Thoughts and Pro Tips<\/h2>\n<p>Sand between coats? Absolutely. Here\u2019s why: it ensures a silky-smooth finish that feels as good as it looks. Stumpy Nubs\u2019 method is straightforward, but it requires patience and attention to detail. Use the right grit, clean up thoroughly, and don\u2019t rush the drying process. Oh, and invest in some <a href=\"https:\/\/amzn.to\/3Z4o9Jg\" title=\"Isotunes Bluetooth Earbuds on Amazon\">Isotunes Bluetooth earbuds<\/a>\u2014because woodworking should be as enjoyable as it is rewarding.<\/p>\n<p>Here\u2019s a quick recap of the steps:<\/p>\n<ol>\n<li>Sand the first coat with 320-grit sandpaper.<\/li>\n<li>Clean up the dust with a vacuum and mineral spirits.<\/li>\n<li>Apply subsequent coats, sanding with 600-grit between each.<\/li>\n<li>For the final coat, wait at least 24 hours and use 1000 to 1500-grit sandpaper or a brown paper bag.<\/li>\n<\/ol>\n<h2>Thought-Provoking Questions for You<\/h2>\n<p>What\u2019s the most challenging part of finishing your woodworking projects? Have you tried sanding between coats, or do you have a different method? Share your thoughts in the comments below! And if you\u2019re not already part of the <a href=\"https:\/\/www.inthacity.com\/blog\/newsletter\/\" title=\"iNthacity Community\">iNthacity community<\/a>, what are you waiting for? Join us in the Shining City on the Web, where we celebrate craftsmanship, innovation, and the joy of creating something with your own two hands.<\/p>\n\t\t\t<div \n\t\t\tclass=\"yotu-playlist yotuwp yotu-limit-min yotu-limit-max   yotu-thumb-169  yotu-template-grid\" \n\t\t\tdata-page=\"1\"\n\t\t\tid=\"yotuwp-6a04f8c33ac0b\"\n\t\t\tdata-yotu=\"6a04f8c35874b\"\n\t\t\tdata-total=\"1\"\n\t\t\tdata-settings=\"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\"\n\t\t\tdata-player=\"large\"\n\t\t\tdata-showdesc=\"on\" >\n\t\t\t\t<div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"yotu-wrapper-player\" style=\"width:600px\">\n\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"yotu-player\">\n\t\t\t\t\t\t\t<div class=\"yotu-video-placeholder\" id=\"yotu-player-6a04f8c35874b\"><\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<div class=\"yotu-playing-status\"><\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div class=\"yotu-pagination yotu-hide yotu-pager_layout-default yotu-pagination-top\">\n<a href=\"#\" class=\"yotu-pagination-prev yotu-button-prs yotu-button-prs-1\" data-page=\"prev\">Prev<\/a>\n<span class=\"yotu-pagination-current\">1<\/span> <span>of<\/span> <span class=\"yotu-pagination-total\">1<\/span>\n<a href=\"#\" class=\"yotu-pagination-next yotu-button-prs yotu-button-prs-1\" data-page=\"next\">Next<\/a>\n<\/div>\n<div class=\"yotu-videos yotu-mode-grid yotu-column-3 yotu-player-mode-large\">\n\t<ul>\n\t\t\t\t\t<li class=\" yotu-first yotu-last\">\n\t\t\t\t\t\t\t\t<a href=\"#WbKgxJDVeYo\" class=\"yotu-video\" data-videoid=\"WbKgxJDVeYo\" data-title=\"I figured out why your polyurethane is bumpy!\" title=\"I figured out why your polyurethane is bumpy!\">\n\t\t\t\t\t<div class=\"yotu-video-thumb-wrp\">\n\t\t\t\t\t\t<div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img  title=\"\" decoding=\"async\" class=\"yotu-video-thumb\" src=\"https:\/\/i.ytimg.com\/vi\/WbKgxJDVeYo\/hqdefault.jpg\"  alt=\"hqdefault 5 Reasons Why Your Polyurethane Finish is Bumpy and How Minwax Can Help Fix It\" >\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<h3 class=\"yotu-video-title\">I figured out why your polyurethane is bumpy!<\/h3>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"yotu-video-description\"><\/div>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\n\t\t\t\t<\/ul>\n<\/div><div class=\"yotu-pagination yotu-hide yotu-pager_layout-default yotu-pagination-bottom\">\n<a href=\"#\" class=\"yotu-pagination-prev yotu-button-prs yotu-button-prs-1\" data-page=\"prev\">Prev<\/a>\n<span class=\"yotu-pagination-current\">1<\/span> <span>of<\/span> <span class=\"yotu-pagination-total\">1<\/span>\n<a href=\"#\" class=\"yotu-pagination-next yotu-button-prs yotu-button-prs-1\" data-page=\"next\">Next<\/a>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t\n<p><strong>Wait!<\/strong> There's more...check out our gripping short story that continues the journey:\u00a0<a href=\"https:\/\/www.inthacity.com\/blog\/fiction\/captain-alex-starship-drama-futuristic-craftsmanship-glissendo-adventure\/\" title=\"Read the source article: \" glissendo>Glissendo<\/a><\/p>\n<p><a href=\"https:\/\/www.inthacity.com\/blog\/fiction\/captain-alex-starship-drama-futuristic-craftsmanship-glissendo-adventure\/\" title=\"Glissendo Backdrop\"><img  title=\"\"  alt=\"story_1737278331_file 5 Reasons Why Your Polyurethane Finish is Bumpy and How Minwax Can Help Fix It\" decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/www.inthacity.com\/blog\/wp-content\/uploads\/2025\/01\/story_1737278331_file.jpeg\"><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Woodworkers know a smooth finish is crucial, and sanding between coats is the key. Stumpy Nubs advises starting with 320-grit sandpaper, cleaning thoroughly, and progressing to 600-grit for subsequent coats. Patience and precision ensure a flawless result, with 1000-1500 grit or a brown paper bag for the final touch.<\/p>\n","protected":false},"author":2,"featured_media":8017,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1686],"tags":[1687,1688],"class_list":["post-8018","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-woodworking","tag-crafts","tag-woodworking"],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/www.inthacity.com\/blog\/wp-content\/uploads\/2025\/01\/feature_image_1737277993.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/posts\/8018","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/comments?post=8018"}],"version-history":[{"count":0,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/posts\/8018\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/media\/8017"}],"wp:attachment":[{"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/media?parent=8018"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/categories?post=8018"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.inthacity.com\/blog\/wp-json\/wp\/v2\/tags?post=8018"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}