Asked on Dec 21, 2014

Can you add polyurethane to flat interior paint to get the gloss look?

Vickie Burniett
by Vickie Burniett

We have 5 gallons of flat interior paint that we would like to turn into a semi gloss with out having to spend the money to get another 5 gallons of paint. My husband said that there is a water based polyurethane out on the market, so we were wanting to know if we could just add a little to the paint to get a glossy shine to it .

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  24 answers
  • Hope Williams Hope Williams on Dec 22, 2014
    No you should not mix them. They will separate terribly on the wall. But you can use it as a top coat with no problem.
  • Michelle Sheets Michelle Sheets on Dec 22, 2014
    As a former paint rep, I can tell you that paint is created in the factory to a very specific formula, and adding something as drastic as polyurethane to it could have a tremendously adverse effect. You also don't mention if the paint and polyurethane are oil or water based. If you mix a oil base product with a water based product you will end up with a tremendous unusable mess. I agree with Hope, your safest option if you wish for a gloss look is to paint your wall then topcoat with the polyurethane. Good luck! :)
  • Paula Jones Paula Jones on Dec 22, 2014
    I'm not an expert on this, but I've been adding polyacrylic to boost the sheen for years with no problems. Just keep a stir stick in the can and stir each time before you pour, that way your sheen will be consistent and that is also true for any paint with some gloss. When I want to remove gloss to make a paint similar to chaulk paint that sands well, I add about a cup of plaster of paris to a gallon of paint. I especially like that painting over MDF since it tends to go on thicker and can fill in the roughness of the board and then sands smooth very easily.
  • no no no,,,you can't mix. why do you want semi-gloss on your walls anyway?? Unless you are doing a bath or kitchen. and even then, no. Get the specific paint for whatever it is you are doing. Now if you want to paint furniture and then put the poly on top of it, by all means.
  • Brenda LeCloux Brenda LeCloux on Dec 22, 2014
    If both the paint and poly are waterbase I would paint first then poly on top. Double the work but I agree I would not mix them. Or you could mix just a little and at with it to see what happens.
  • I am not a fan of flat paint but it does have its advantages- hides flaws in the walls and it is cheaper. Most flat paints are washable and are much better than the paints of years ago so I would not worry about using it especially if it is washable. I would not ever put polyurethane on the walls. I once did a job for a client who had poly on the wall to keep a mural glossy. It was a nightmare- I had to prime the wall several times after the paint would slide off the walls! Paint is not that expensive if caught on sale and I would not put semi gloss on walls unless it is in a bathroom. Semi gloss shows all flaws plus there is no need with paints in satin for some sheen. good luck.
  • Sheryll S Sheryll S on Dec 23, 2014
    I do not know if you can do this or not...... but oh my ........ shiny shows every little crack or nail filled spot on the wall. And here in my Florida tiny home, even the stud nails show....... so NO shiny on walls. It will be ugh.
  • Terry's Flooring Terry's Flooring on Dec 23, 2014
    I'm all about what Beth H. said ..
  • Maya Sylvan Lee Maya Sylvan Lee on Feb 10, 2017

    One person here said Vickie didn't say if the poly she's thinking of using is water-based. Yes she did: water-based.  Vickie also said she wants semi-gloss, but didn't say for what. Although this is commonly used in kitchens & bathrooms, maybe she wanted it for something other than walls. A lot of assumptions here. Also, a lot of guesses stated as fact. I made note of what Paula said  as she's actually experimented with a few things and has had good results. I have some flat paint & I came to this page curious about adding WATER-based poly. I don't want gloss, I want something maybe a tad shinier than satin because it's my mud room. No matter the quality of flat paint, it is more difficult to clean. It's nature is to absorb, which would include fingerprints & any kind of spatters. My walls are very textured in the SW style, so any gloss highlighting imperfections would not matter. I'm going to go do a test right now.  Be back when it's dry................ 4 hours later: Success!  I mixed approximately 1 part water-based polyurethane with 5 parts paint. It went on perfectly and has now dried to a light sheen. Good luck to all wanting to give it a try.

    ~And thank you to the maker of this forum for offering all the fun emojis. Life's too short to not try & get a little fun out of most everything.

    • See 3 previous
    • Heather Tiles Heather Tiles on Oct 15, 2020

      Will this work with latex paint

  • Maya Sylvan Lee Maya Sylvan Lee on Feb 10, 2017

    To all the naysayers. I came here looking for an answer similar to Vickie, who DID say she was considering a water-based polyurethane. I followed Paula's advice  as she's the only one who wrote about actually trying to mix paints with various substances, not just hypothesizing. I mixed approximately 1 part water-based polycrylic (not urethane) with 5 parts flat interior paint. Perfect! Went on easily & dried to a nice sheen for my mudroom. No matter how high the quality of flat paint, it is still absorbent. Fingerprints & splatters often need to be painted over. My mudroom, bathrooms & kitchen are all done in satin or something between satin & semi-gloss. I get this by mixing the same color in semi-gloss with satin in equal parts. I have pretty heavily textured wall in the southwestern style, so there is no issue of highlighting imperfections. Good luck to all who try these ideas.

    • See 2 previous
    • Rigo Rigo on Oct 19, 2021

      separate question... did you try both polyurethane and polycrylic? I was a bit confused. I dont know if polycrylic is sold at my local store but urethan for sure is. If you tried both, how did it go?

  • Verna Verna on Jun 04, 2017

    Spray paint over finished product with clear gloss enamel

  • Cul33665126 Cul33665126 on Jun 24, 2018

    Who doesnt want semi-gloss on all walls? Maybe she has kids, walls are horrible in flat. We use a satin or semi-gloss on every wall. If they are both water-based they should mix fine. My husband has been a painter for 25 years, dont let people scare you, lol. Take a little bit and do a test mix.

  • Pam Parziale Pam Parziale on Jun 24, 2018

    There is a company in Maine that makes cottage furniture. When the company first opened, I was in the paint shop and asked how they made their paint so tough. The guy in the paint shop said to mix water based polycrylic to the water based paint, 1 part poly to 5 parts paint. I painted my kitchen cabinets 10 years ago, using this info, and they still look great.

  • Jeanette Warman Blazso Jeanette Warman Blazso on Sep 14, 2018

    I have mixed water based polyacrylic for years & used basically the same formula mentioned by others

  • A Roth A Roth on Nov 27, 2018

    I have no answer but do appreciate everyone's input. I have the paint I want in flat but wanted to make it harder and less absorbent when it's dry. I'm definitely going to try adding some poly! Thank you

  • Cassandra G Cassandra G on Jan 19, 2020

    I came to this site looking for an answer a few months ago. I appreciate the advice of those who had tried it. I decided to mix my flat with the 1/5 ratio and it came out beautifully. I am pleased with the results and hope anyone else looking for this info, goes ahead and tries it.

  • Matthew Catarnichi Matthew Catarnichi on Feb 08, 2020

    I am in the same situation with 5gal of flat paint that I’d like to make into an eggshell. Planning on trying the 5 to 1 ratio but just curious as to what sheen of poly everyone is adding to obtain what sheen of finished product. It appears that satin, matte, semi-gloss, and gloss are all available. Thanks for whatever help people may have.

  • Cynthia M Cynthia M on May 10, 2020

    I have 5 gallons of flat paint that I’ve been using all over my walls and I want to do the kitchen. But flat would be hard to clean in a kitchen. What should I do? Mix it with a gloss Or add a clear gloss? Thnx!

  • Sam aro Sam aro on Sep 09, 2020

    I hate flat paint because it absorbs fingerprints and smudges like a sponge and I am always looking for a good deal on paint because it is so outrageously expensive and I buy the cheap oops paints and mix it up and add tint to get the color I want this so I picked up 10 gallons of oops paint at several different locations and I was disappointed that I didn’t end up with any semi gloss paint and I was stuck with a very nice beige paint that was flat and dry looking so I went to the big orange box and found some water born spar varnish thick deep gloss and mixed 2 gallons into my paint and I was impressed with a very nice sheen and I was able to use my beige oops paint and it looks great and if you ever want to flatten a semi gloss paint to a matte finish you can mix in some cornstarch a little bit at a time to make the sheen you want I used to mix paint at a little hardware store and the old lady who owned the store taught me the best tricks to get what I want without spending a lot of money

    • Roberta Roberta on Oct 22, 2021

      I wish I knew a little old lady like that! I mix up my own chalk paint as the costs are outrageous, just add plaster of,Paris and last batch I added floetrol which gave a wonderful smooth finish. Hadn’t heard of using cornstarch like that. Great idea

  • Sam aro Sam aro on Sep 09, 2020

    Yes you can add a waterborne gloss varnish to your paint to give you the sheen you want and if you need to flatten it out you can add some cornstarch to tone a semi gloss I don’t like the sheen of semi gloss paint and I don’t like the sheen of the matte finish so I tone down semi gloss paint with some cornstarch

  • Bill Bill on Oct 07, 2021

    I would NEVER waste money of flat or eggshell paint. It looks terrible and is usually difficult to clean. Latex-based semi-gloss is the way to go - much easier maintenance! If you HAVE to use flat paint, save it for the ceilings.

    • Lisadoll Lisadoll on Feb 13, 2022

      Well that USED TO Be the case .

      Todays higher quality paints are a bit more advanced

      For instance Benjamin Moore has two “flat” finishes : “matte” and “flat”. They’re both washable and scrubbable . I can attest to that . I painted my entire very small house w that matte paint. As anybody who lives in a shoebox knows- the walls take a beating . ESPECIALLY the hall, and entry. I’ve scrubbed or washed or spot treated those walls many a time with no issues . Sheen looks great . WELL WORTH THE PREMIUM PRICE IM HAPPY TO REPORT. Did I WANT to pay that for paint?! NOPE! I scraped the accounts and I’m grateful now 7 years later !

  • Bekah Cundiff Bekah Cundiff on Oct 21, 2023

    I don't have an answer, I just really love that people have been commenting on this post for the last 8 (almost 9) years lmao🤣

  • Johnavallance82 Johnavallance82 on Oct 21, 2023

    Quick Anser NO! If you do it will cost you more in time and money to rectify it!

  • Janice Janice on Oct 21, 2023

    I'd be skeptical that it would turn out well. You could mix a small sample and apply it to an inconspicuous area to see how it works. Probably best to apply the clear product as a top coat. Either way, I'd do a test patch first.