{"id":1600,"date":"2022-06-24T12:30:00","date_gmt":"2022-06-24T16:30:00","guid":{"rendered":"https:\/\/diywithchristine.com\/?p=1600"},"modified":"2024-02-28T16:20:23","modified_gmt":"2024-02-28T21:20:23","slug":"sanding-between-poyurethane-coats","status":"publish","type":"post","link":"https:\/\/diywithchristine.com\/sanding-between-poyurethane-coats\/","title":{"rendered":"Do You Have To Sand Between Coats Of Polyurethane? Pictures Included!"},"content":{"rendered":"\n

Have you ever wondered what happens if you don\u2019t sand between coats of polyurethane? I did too because I\u2019m LAZY. <\/p>\n\n\n\n

I mean, who has time to apply all of those coats of polyurethane AND sand between them?<\/p>\n\n\n\n

So I ran some tests to show exactly what happens if you don\u2019t sand between coats of polyurethane (and what happens if you do!) Here is what I found:<\/p>\n\n\n\n

The texture of polyurethane is rougher if you do not sand between coats of polyurethane. However, the difference in finish is not visible to the naked eye. Each layer of polyurethane will still adhere together whether you sand between coats or not.<\/strong><\/p>\n\n\n\n

Now that I\u2019ve fully tested my theory, I never have to worry about whether it will ruin my wood project by skipping sanding or not.<\/p>\n\n\n\n

Below, I broke down my findings and how I ran the test, so you can determine whether sanding between coats of polyurethane is worth it for your wood project or not.<\/p>\n\n\n\n

Let\u2019s dive in!<\/p>\n\n\n\n

<\/p>\n\n\n\n

Quick Navigation: What Happens When You Skip Sanding Between Coats Of Polyurethane<\/strong><\/h2>\n\n\n\n
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  1. How The Finish & Durability Turn Out When You Don\u2019t Sand Between Coats Of Polyurethane<\/a><\/li>\n\n\n\n
  2. Skipping Sanding Between Coats Of Polyurethane Results<\/a><\/li>\n\n\n\n
  3. Sanding Between Coats Of Polyurethane Results<\/a><\/li>\n\n\n\n
  4. Why Do Polyurethane Manufacturers Recommend Sanding Between Coats?<\/a><\/li>\n\n\n\n
  5. What Happens If You Don\u2019t Sand Between Coats of Polyurethane?<\/a><\/li>\n\n\n\n
  6. Why You Might Not Want To Sand Between Coats<\/a><\/li>\n\n\n\n
  7. How Many Coats of Polyurethane Should You Apply?<\/a><\/li>\n\n\n\n
  8. How Long Should Polyurethane Dry Between Coats? (Sanding Or Not)<\/a><\/li>\n\n\n\n
  9. How To Sand Polyurethane Between Coats<\/a><\/li>\n\n\n\n
  10. Other FAQs About Applying Polyurethane<\/a>\n
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    1. What Grit Sandpaper Should You Use To Sand Polyurethane?<\/a><\/li>\n\n\n\n
    2. Do You Sand The Final Coat Of Polyurethane?<\/a><\/li>\n\n\n\n
    3. Is It Better To Brush Or Roll Polyurethane?<\/a><\/li>\n\n\n\n
    4. What Do You Do With A Polyurethane Brush Between Coats?<\/a><\/li>\n\n\n\n
    5. Can You Apply Polyurethane Over Old Polyurethane?<\/a><\/li>\n<\/ol>\n<\/li>\n\n\n\n
    6. Final Thoughts<\/a><\/li>\n<\/ol>\n\n\n\n

      <\/p>\n\n\n\n

      How The Finish & Durability Turn Out When You Don\u2019t Sand Between Coats Of Polyurethane<\/strong><\/h2>\n\n\n\n

      To test how much sanding between coats of polyurethane truly affects the finish and durability, I stained and taped off 7 sections on a piece of pinewood.<\/p>\n\n\n

      \n
      \"what
      No coats of polyurethane had a rough texture and was easily scratched.<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      I tested the finish differences between no coats, 1 coat, 2 coats sanded between, 2 coats unsanded, 3 coats sanded between, 3 coats unsanded, and 3 coats sanded between with the final coat being sanded as well.<\/p>\n\n\n\n

      Here are the results I found:<\/p>\n\n\n\n

      Coats Of Polyurethane<\/th>Finish<\/th>Durability<\/th><\/tr><\/thead>
      None<\/td>Rough<\/td>*Easily Scratched<\/td><\/tr>
      1 Coat<\/td>Rough<\/td>*Easily Scratched<\/td><\/tr>
      2 Coats, No Sanding<\/td>Slight Roughness<\/td>*Hard To Scratch<\/td><\/tr>
      2 Coats, Sanding<\/td>Smooth<\/td>*Hard To Scratch<\/td><\/tr>
      3 Coats, No Sanding<\/td>Slight Roughness<\/td>*No Scratches<\/td><\/tr>
      3 Coats, Sanding<\/td>Smooth<\/td>*No Scratches<\/td><\/tr>
      3 Coats, Sanding Including Final Coat<\/td>Rough<\/td>Scratched From Final Sanding<\/td><\/tr><\/tbody><\/table>
      *Scratched with a fingernail<\/figcaption><\/figure>\n\n\n
      \n
      \"what
      One coat feels similar to no coats of polyurethane. It was still rough and way too easy to scratch.<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      Skipping Sanding Between Coats Of Polyurethane Results<\/strong><\/h2>\n\n\n\n

      There were obvious differences texture-wise between the areas of wood where I sanded between coats of polyurethane and the areas where I skipped the sanding.<\/p>\n\n\n\n

      When I ran my hand over the unsanded areas, I could feel tiny bumps and a slight roughness to the wood.<\/strong><\/p>\n\n\n\n

      But to the naked eye, I could not tell a difference visually between the sanded and unsanded areas of wood.<\/strong><\/p>\n\n\n\n

      That is excellent to know because if you are short on time, or if you are building a project that doesn\u2019t matter if the texture isn\u2019t perfectly smooth, then you can skip the sanding between coats.<\/p>\n\n\n

      \n
      \"small
      You can kind of see the little bumps I’m referring to on the far left bottom rectangle. It is not noticeable to the naked eye, but I can feel it.<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      We did not sand between coats when we applied polyurethane to our floating fireplace mantel. (If you\u2019re curious as to how we built our mantel, you can find my tutorial here<\/a>.)<\/p>\n\n\n\n

      Again visually, you cannot tell that we didn\u2019t sand it.<\/p>\n\n\n\n

      And even when you run your hand over it, the texture is smooth enough that you wouldn\u2019t notice a difference.<\/p>\n\n\n

      \n
      \"fireplace
      I love how our mantel turned out!<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      From the various wood projects where I skipped the part of the directions that told me to sand, I\u2019ve never had the polyurethane peel off or have an issue adhering together.<\/p>\n\n\n\n

      <\/p>\n\n\n\n

      The Secret To Getting A Perfect Polyurethane Finish Without Sanding<\/strong><\/h3>\n\n\n\n

      The main reason the polyurethane directions tell you to sand between coats is to buff out any drip marks or brushstrokes before you apply a second or third coat.<\/p>\n\n\n\n

      If you do have any obvious unevenness between coats, then you\u2019ll want to sand. But my secret to avoiding brushstrokes in my polyurethane is to use a foam brush.<\/strong><\/p>\n\n\n

      \n
      \"what
      I love to use foam brushes and foam rollers when I apply polyurethane. They make the application and clean-up process so much easier!<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      Yes, it\u2019s that simple! I love to use these cheap, disposable foam brushes found at Amazon<\/a> because they leave behind a smooth finish, and I can throw them away when I\u2019m done with them. <\/p>\n\n\n\n

      (That\u2019s always preferable with oil-based products because they\u2019re a pain to clean haha.)<\/p>\n\n\n\n

      If you use that type of brush, then I wouldn\u2019t worry about sanding between coats of polyurethane.<\/p>\n\n\n\n

      Also, oil-based polyurethane does a better job of leveling out brushstrokes than water-based (because it dries slower so it has more time to level out). <\/strong><\/p>\n\n\n\n

      So that also aids in the argument to skip sanding between coats.<\/p>\n\n\n\n

      <\/p>\n\n\n\n

      Sanding Between Coats Of Polyurethane Results<\/strong><\/h2>\n\n\n\n

      Now, there is a texture difference if you sand between coats of polyurethane.<\/p>\n\n\n\n

      Even with only two coats of polyurethane, the finish was amazingly smooth to the touch and had no imperfections when I sanded between coats.<\/strong><\/p>\n\n\n

      \n
      \"what
      2 coats of polyurethane on both of these. The left one I didn’t sand, and the right one I did. These two were smoother and harder to scratch. (Needed lots of pressure to scratch with my fingernail.)<\/figcaption><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      And when the third coat was added, the wood project was smooth and durable. The exact type of finish I\u2019d like to see on a tabletop that sees a lot of daily use.<\/p>\n\n\n\n

      But I find it hard to say you need to sand between coats of polyurethane on every project.<\/p>\n\n\n\n

      So my stance is this: If you have drip marks or brushstrokes, then a light sanding will help even out the finish and create a smooth project. <\/strong><\/p>\n\n\n\n

      But if you use a foam brush and apply even, light layers of polyurethane, then it\u2019s better to just save your time and skip the sanding between coats.<\/strong><\/p>\n\n\n

      \n
      \"what
      3 coats of polyurethane were applied. The ultimate finish is 3 coats with light sanding between. But 3 coats without sanding was a close second!<\/figcaption><\/figure><\/div>\n\n\n

      I\u2019ve also used MinWax\u2019s Water-Based Polycrylic found at Amazon<\/a> and lightly sanded between coats using 600 grit sandpaper for this console table I built.<\/p>\n\n\n\n

      And I skipped the sanding between coats on Polycrylic for this small end table<\/a> I built out of scrap wood.<\/p>\n\n\n\n

      The outcomes were the same as the oil-based polyurethane:<\/p>\n\n\n\n