Tips on Pouring Acrylic

by | Jan 21, 2009 | Blog | 17 comments

I get a lot of requests for tips to pouring acrylic. To get a very smooth glossy finish, pouring acrylic mediums is a great way to accomplish that “surfboard finish”. Pours are also cool ways to get smooth evenly applied glazes or transparently colored overlays.

My favorite pouring mediums are (these are all Golden products) Clear Tar Gel, Self-Leveling Gel, and GAC800. The Clear Tar Gel and Self-Leveling Gel both need about 20-40% water added if you are pouring in a dry warm climate – like out here in New Mexico. You don’t need to add water in wet cool climates.

Adding water will enable a thinner layer to be applied. If you apply it too thickly, the top part of the layer will dry first, then the rest of the acrylic will dry slower and shrink down in volume, creating crevises or cracking on the top. Its better to pour a few thin layers, one on top of the other after they dry, then one thick layer that may crack.

GAC800 does not need any water added, as it is made especially for pouring, and can be poured very thickly without crevising or cracking. The GAC800 is the easiest to pour, but has a slight yellow or cloudy look to it, that is more noticeable the thicker the pour. I like to use this in thick layers to simulate a wax or encaustic look.

When I pour, I pour very gently, from a low height and a soft angle. If you pour from a high height, or vigorously, the medium may jolt out of the container creating bubbles. A light spray of alcohol on the surface before pouring, or even after pouring while the medium is still wet will eliminate bubbles too.

More pouring articles:

5 Acrylic Pour Painting Techniques for 2020

Pouring Acrylic – the HOT new painting craze

How to Make Acrylic Paint Look Like Enamel

Pouring Resin-like Finishes

For more information on pouring, check out Nancy Reyner’s book Acrylic Illuminations.

17 Comments

  1. Jill

    As a beginner I am learning new techniques every day. My problem is “cracks”. I can make a beautiful piece but after it dries there are a lot of cracks, mostly in the thick areas. How can I thin out the thick areas without loosing all the cells and colours where I want them to stay?

    Reply
    • Nancy Reyner

      Hi Jill,
      Cracks, also called “crevicing” are an issue with some aspects of acrylic. Acrylic will shrink down in volume by about 30% while drying. This means whatever thickness you apply a layer, it will eventually dry alot less thick. If the top of this layer dries faster then the shrinkage it will crack. This is an issue when applying thick layers of mediums, but gels are already thick so these will shrink in volume but without cracking. It is the thinner mediums, or thin paints, where this cracking happens. It will happen more when the climate is dry or hot, because in these climates the top part of your layer will often dry faster then the whole layer can do its shrinkage. To resolve cracking issues, you can do several things. You can put a plastic “tent” over your work area and add a humidifier. You can also apply your mediums and paints thinly all over and build up the thicker areas in separate layers, allowing each to dry before applying the next. Also, another tip is to only pour mediums over a non-absorbent surface. If you apply a pour over an absorbent surface (you can tell its absorbent if its matte) the pour will soak into the surface before it dries creating an uneven surface which will encourage cracking). By sealing your surface first with a gloss medium, then wait until its dry, then pour – you will decrease cracks. One more tip – use a pouring medium that is meant to not crevice, like Golden’s GAC 800. Hope these tips help!

  2. Lindy Sharpe

    Hi Nancy, I am a newbie to acrylic pouring & have achieved a few good pours & lots of Fails but still enjoying the process, BUT on a negative space pour have found that after leaving overnight it has spread considerably & not retained its shape 😂 I am using pva glue for the medium HELP as they are great when done but disappointed later. Thanks for your time 😃

    Reply
    • Nancy Reyner

      I have not used PVA glue for pouring, but think this may be the culprit for your issue. I think a pouring medium that holds its shape while drying would work better for you. Have you tried Golden’s Clear Tar Gel? I use this with about 30% filtered water added to it the night before. I stir it then wait overnight so the bubbles dissipate. When poured it will spread a small amount right away, and you can use a spatula to create the shape you want, and then it should stay that way while drying. Let me know if this works for you.

  3. Jennifer Jones

    Hi Nancy,
    I’m having a rough time getting the surface of my pours smooth. Often times they turn out with a “mottled” finish-no cracking. What am I doing wrong? Also, I recently moved to a cold climate with low humidity. The indoor temps are kept at about 68 degrees. Would these conditions affect my pours? If so, what should I do to correct that?

    Reply
    • Nancy Reyner

      Hi Jennifer, Getting smooth pours can take a bit of fussing until you figure out what works best with your environment – as temperature and humidity will affect results. I suggest trying some experiments, work on small surfaces as tests. First make sure the surfaces are sturdy and won’t warp with heavy applications of wet products such as pours will give. Next make sure the surface is level, by using a leveler. If the surface is even slightly not level, the pour layer will keep moving just slightly enough to cause ripples and this may be the mottled surface you are seeing. Test also to see if raising the temperature to above 70 degrees will help. If you have no control over the temperature, then add a small space heater not too close to the work, but enough to keep the room warmer. Have a fan or air moving in the room while it is drying. Another thing to pay attention to is the thickness of the pour, and the quality of the product you are using to pour. For pours I recommend using products made especially for this. I also recommend pouring thinly first to get an even pour. Once you attain an even surface pour then you can try going thicker if you want. Its easiest to pour thinly, then build other thin pours on top until you reach the thickness you want. Start with one of the changes I mentioned above, test just that, then keep going until one of my suggestions resolves your issue. Your mottled description makes me theorize it is a combinatino of three things: to cool a temperature, not level and too thick a pour. Let me know if this helps resolve it!

  4. Nancy Reyner

    Dear Jessie,
    I think you mean Technique 94, which is on page 109. You can use Heavy Body paints instead of Fluids to add to the Clear Tar Gel. You are only adding about 10% color paint to 90% gel, so it won't matter which type of paint you add. If you use Clear Tar Gel for a pour, I recommend adding 20% water to it, which helps keep the pour thin. It's better to add several thin layers (one of top of the other when dry) then one thick layer which may crevice.

    Reply
  5. Jessie

    Hey there Nancy!

    I have a question about pouring with clear tar gel. In your book (pg 94) layers of fluid acrylics are poured onto a red canvas to mix together and create a beautiful swirling pattern in the center of the lines. How would I achieve this affect using clear tar gel and watered-down heavy body acrylics (I'm on a limited budget and I can't afford to buy both fluid and heavy-body)? Is clear tar gel too heavy to create such an effect?

    Reply
  6. Emily

    Thank you so much Nancy- that does help! It’s funny, I have always stuck to my good old matt medium, but it is fun playing all the gels:: I guess I am learning through experimentation! I am working on filling with some heavy gel I have, and then I will try another pour later. Off to get some GAC800! xo

    Reply
  7. Nancy Reyner

    Hi Emily,
    Pours are tricky as you have discovered. The best pouring medium is Golden’s GAC800, made especially for pouring without having any crevicing. To fix the crevicing with more pouring will just increase the problem. The only solution, now, to fix the crevices, is to push a thick gel into the cracks, let it dry, repeat until the surface is smooth, then pour over the entire surface with the GAC800. If you want to still use the Self Leveling Gel for pouring, then add about 30% water to it, pour, and spread so it is a very thin layer. You can build up layers after each layer dries, but pouring one thick layer will just add more crevicing.
    Hope this helps.

    Reply
  8. Emily

    Thanks for the great post (and great book!). I did a pour with self leveling gel, and I got the cracking… argh. Is it worth trying to save it with thin pours (self leveling with water) as you state in this post- or is it ruined? thanks for the help!

    Reply
    • violet buthmann

      hello
      I’m unable to get cells. I’ve poured many canvases but still no cells. I get a marbled look which is pretty but no cells.
      I look forward to your suggestions.
      thank you
      violet

    • Nancy Reyner

      Hi Violet,
      It is very tricky to get cells. Once you find the right combination, though, then it becomes much easier. Cells are created using a combination of things that need to find the right balance with each other. One of these is drying times, and that differs depending on the humidity and temperature where you are pouring. Another important aspect is to find the right mixture proportions for your climate. You want to make sure you have mostly pouring medium for your first experiments. Your mixture consists of pouring medium, paint color and alcohol. Each paint color has a different weight. By using small amounts but of a variety of colors, you will get better results. For instance, Titanium White is very heavy, and Quinacridone Magenta is very light in weight. Add at least 3 or 4 colors to your mixture, making sure they have different weights. Because you are adding several colors, it is easy to add too much paint color to pouring medium. Add very very small amounts of each paint color, so that by the time you add 4 colors, you still have 70-90% pouring medium in the mixture. The alcohol moves the lighter weight paints upwards through the poured paint layer, and leaves the heavier weight paints to sink down. This movement, along with having both light and heavy weight paint colors, will create the cell. If you only use one color, you won’t get a cell, which is actually an outline of one color around another. If your surface is absorbent, as in using canvas, primed canvas, or paper, the pour will sink into the surface, which doesn’t allow the pour time to separate colors into cells. If you don’t pour your mixture thickly enough, this will also allow the pour to dry too quickly so the colors don’t separate into cells. For best results use a rigid surface like a wood panel, that is sealed by applying a gloss medium (this keeps the pour on top of the surface instead of sinking into it), make sure the panel is level (!!!very important because if it isn’t level, the pour will move towards the lower side, and making it too thin on one side to dry slow enough for the cells to form. Hope this gives you some helpful guidelines to get the cell pouring you are looking for.
      Nancy

  9. Jan

    Great tips. Very helpful for a newbie like me. Thanks!

    Reply
  10. Kris Hardy

    Great tips, thank you. I love your book but it is really great to hear your tips.

    Reply
  11. Cindy Davis

    Very helpful info Nancy. Still digging into your book, always find something new each time I look at it.

    Just like raccoons, I love shiny things!

    A shiny finish on a painting can really make the color glow. (in my opinion)

    Reply

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About Nancy

Nancy Reyner paints exotic versions of heaven, using gold leaf and other unusual materials. A contemporary abstract painter, she feels art is a rewarding pursuit that adds quality of life. Nancy shares this passion with her students & offers classes, articles, books & videos, encouraging the courageous use of materials and artistic expression.

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