barb blairbefore & after basics

before and after basics: polyurethane

by Barb

Hello everyone! I can’t believe it’s already Thursday — this week just flew by. Thank you for all of the suggestions last week. I’m going to try and tackle them one at a time, starting today with polyurethane.

Many of you have asked how to apply it, what tools work the best and whether you should use water-based or oil-based varieties. In today’s Before and After Basics, I hope to answer all of your questions about this tricky liquid! — Barb

CLICK HERE for the full how-to after the jump!

Water-Based Polyurethane (I really love a matte finish)


  • foam brushes
  • soft-bristle synthetic brush
  • fine-grit sand paper
  • foam roller

In reading lots of articles on application, you will find that some people prefer to use foam brushes and some prefer bristle brushes for application. I personally do not like foam brushes, as they get over-saturated and fall apart! It makes for a frustrating venture, so I use either a bristle brush by itself or along with a foam roller.


1. Make sure that you never shake a can of polyurethane as it will cause air bubbles to form in your finish. Gently stir with a stir stick. If you are using just the brush, you can dip right out of the can, but if you are going to use a roller, pour the poly into a tray.

2. Roll the poly onto the surface, making sure your paint strokes are in the same direction — do not work the roller back and forth, as this will leave lines and uneven spots in its wake! When working with any type of poly, it is super important to remember this step. Over-working with a roller or brush breaks the chemical reaction in oil-based poly and causes streaks in water-based poly because of the fast drying time. So work fast and in long, even strokes.

3. If you notice air bubbles after applying with the roller, go back over the surface lightly with your brush to smooth them out. Use a very light hand in this — you just want to skim the surface and not dig into the finish. You can do the whole application with a brush if you like and skip the foam roller. It is entirely up to you and what you find works best. Try it both ways and come up with your favorite finish.

4. Allow product to dry according to directions on the can, which is normally around 1 to 2 hours.

5. Lightly sand the surface with fine sand paper before applying a second coat. Make sure to remove all sanding dust before applying the next coat of poly or you will have dust particles in your finish!

6. Apply a total of 2 to 4 coats of poly depending on the needs of the piece.

Oil-Based Polyurethane


  • china bristle brush
  • fine sand paper
  • mineral spirits
  • staining pads

Some suggest using mineral spirits to thin out the first coat of oil polyurethane, and you can totally do this. I use a product called Arm-R-Seal by General Finishes that I find doesn’t need to be thinned down. This has been the best oil product for my furniture products.


1. Using a natural-bristle brush, apply the poly in long, smooth strokes (going with the direction of the grain) overlapping the previous stroke just a bit to ensure proper coverage. Remember again not to over-work the brush as it will disrupt the finish.

2. One thing to be careful of with oil is drips! Check for drips and go back with your brush to smooth them out.

3. Oil takes longer to dry than water-based poly, so read the instructions on the can very carefully! Let fully dry.

4. Sand very lightly over the entire surface. Again, I can’t stress enough how important it is to remove all of the dust and to have a very smooth, clean surface before applying the second coat. Many make this mistake and end up with a bumpy, uneven finish.

5. Apply 2 to 4 coats and you have a very durable surface for your furniture!

Here are my thoughts on water- versus oil-based poly: Water-based products have their advantages; they are safer for the environment and working area, they dry fast, are easy to clean up, easy to apply, will not yellow over time and are quite durable as a finish. Oil-based products are more harmful to breathe in, (please make sure to wear a mask and use all necessary safety precautions), require longer drying times and can be tricky to apply.

In my experience, I’ve found the water-based poly to be all I need for most furniture pieces, but when working on a piece that will be used for a dining room table or sink, I go with oil. Oil-based finishes are still the strongest and most durable for surfaces that get lots of wear and tear.

So, that’s my two cents in the polyurethane department and it’s based purely on my experience with furniture. I hope that clears up some of your questions surrounding this process!

See you all next week!

Note: A great source for these products and more is your local Woodcraft store.

Suggested For You


  • Hi there! Thank you so much for all the wonderful advice! I have recently been getting into refinishing furniture. My most recent piece is a coffee table I spray painted a plum color, then stenciled a pattern across the entire table top. I have just completed my first layer of oil-based poly. My question is this: will it ruin/affect the paint job underneath the poly when info to sand in preparation for my second coat?? The paint job is beautiful (if I do say so myself) and I would be totally bummed if all my hard word was ruined!

  • Alicia, as long as you wait long enough, and allow the poly to dry completely, and then sand lightly, the integrity of the paint should hold. Be patient, do things methodically, little steps at a time

  • I painted my bathroom floor and put 3 costs of polyacrylic on. It looked beautiful! I gave it a couple of days, then started sanding my bathtub. I thought the poly had plenty of time to dry, but after sanding, dust particles are in there and I can’t seem to remove them. Anyone have any ideas? I hate the thought of starting over.

  • I just made a wooden coffee table, stained it using Minwax Walnut. What is the best way to go about protecting this table? Poly with a brush? I’m a newbie DIYer :)

  • When using any kind of urethane water or oil based you go through different grit of sand paper before stain or sealer or applying finish make sure you have a grit free floor make sure to vacuum it and pop the grain the vacuum again when dry the apply

  • For wendy was the stair case ?sanded before staining a floor make sure you have a clean surface then you stain. Then you add sealer after stain has dried but before adding finish samething drying time

  • I painted watered based poly over chalk paint. It is yellowing how can I take it off with out messing up the paint?

  • Polyurethane lasts a long time, when repainting soon you can leave the brush in a bit of paint and it will be fine the next day. For longer time periods simple soap and warm water until it runs clear is good enough to last a long time, just remember that the bristles usually dry and you want them in the same form to make it easy with cutting in.

  • My last coat of oil based varathane bubbled everywhere and there are pits in it where I was kneeling on it….I’m doing stairs. Do I have to sand down to the wood again?

  • what can I put on my newly polyed floors to help them dry? oil based someone said wipe lightly with mineral spirits?

  • I completed one nightstand with Anne sloans paint,like but hate the fell of the wax on furniture plus I dident know there was upkeep. I’m trying to remove wax with mineral spirits, I. Going to try scuffing with one of those gree pads.i know I can Shellac or prime and repainted, but want this wax off then plan to use general finish, any advice

  • Hello We just put the first coat of minwax polyurethane oil clear satin on our pine floors. We dont like how yellow it looks and we want to put a color based minwax polyurethane oil. Can we do this for the last 2 coats?

  • hello, every time I use a clear coat product, my brush get a lot of foam, and it will transfer unto my work. I wipe the brush with a dry cloth but still have this issue.

  • I applied chalk paint, then clear waxed my item. I”d like to put an antiquing glaze on it to make the applique wood designs show up better. Can I use poly over the wax so I can rub the glaze off the parts I don’t want glazed?

  • I used water based poly over chalky paint. I now have a streaky piece of furniture. How should I proceed to fix this problem.

  • Working on too many projects at the same time. I inadvertently painted a coat of metallic latex paint over a coat of water-based polyurethane. It has dried and looks fine. What should I do now. I am thinking about just applying another coat of poly over the latex.
    Think that would work? Should I sand first?

  • Hello,

    Lemon Pledge was accidentally applied to my beautiful redwood burl coffee that has what I think is a polyurethane finish and left a filmy residue. My question: what can I use to remove the film without harming the finish? I tried a litttle soapy water and also some vinegar water. Both only spread the film.

    Hopeful in LA,


  • Hi, Barb good info… I am about to repaint a guitar with polyurethane, but I cannot find info on what goes first, sprayed color or base coat?

    From what I have read, this are my two options:
    1) color / base coat / clear coat
    2) base coat / color / clear coat

    What do you think? Do you have any recommendations?

    Thanks in advanced, love from Mexico


Leave a Reply

Design*Sponge reserves the right to restrict comments that do not contribute constructively to the conversation at hand, contain profanity, personal attacks, hate speech or seek to promote a personal or unrelated business. Our goal is to create a safe space where everyone (commenters, subjects of posts and moderators) feels comfortable to speak. Please treat others the way you would like to be treated and be willing to take responsibility for the impact your words may have on others. Disagreement, differences of opinion and heated discussion are welcome, but comments that do not seek to have a mature and constructive dialogue will not be published. We moderate all comments with great care and do not delete any lightly. Please note that our team (writers, moderators and guests) deserve the same right to speak and respond as you do, and your comments may be responded to or disagreed with. These guidelines help us maintain a safe space and work toward our goal of connecting with and learning from each other.