Canvas is one of the most popular painting mediums as it has a flexible and malleable surface. If you have a painted canvas and want to repurpose it for a different paint, there are easy ways to prime it for reuse. If it was originally painted with acrylic paints, you can dip it in rubbing alcohol. That way, you can loosen a large amount of paint before priming the surface. For a canvas originally painted with oil paint, you will need to scrape and sand the paint to remove it. If you want a cool, clean surface you can work on, you can always flip the canvas over on its unused side to paint it. Once you're done, you can start painting again!
Part 1 of 4: Painting on Acrylic Paint on Canvas
Step 1. Sand the paint with 120-grit sandpaper to remove any texture
Apply pressure firmly to the canvas, but don't use too much pressure to tear the canvas. Work in circular motions around painted areas that have a raised or bumpy texture. Continue rubbing them with the sandpaper until they are level with the rest of the canvas surface.
- You don't need to sand the canvas if you don't have any raised texture.
- If you don't sand the canvas, the original texture will still show through the paint and look uneven.
This method works best on paintings or canvases that are slightly colored, as the paint will not show through much.
Step 2. Apply a thin layer of white acrylic paint to the canvas
Dip the end of a 2-inch (5.1 cm) natural bristle brush into the paint and spread it over the canvas. Work your way back and forth, either horizontally or vertically for the first layer. Spread the paint so that the canvas has a thin, even layer that covers the original paint.
- Avoid repainting over dark art pieces, as it will be difficult to hide the original colors.
- Don't apply the paint in too thick layers or it will take a long time to dry. It's okay if the original paint still shows through the first coat.
Step 3. Let the paint dry to the touch
Leave the canvas in a cool, dry area out of direct sunlight while it dries. After about 30 minutes, check the paint for drying by tapping it with your finger. If you don't see paint on your finger, you can continue. If not, let it dry longer and check again in 15-20 minutes.
Step 4. Paint another coat of white in the opposite direction
If you painted the first layer vertically, apply the second with horizontal strokes. Fill in any areas that you missed in the first coat or areas where you can still see the original paint. Make sure the second coat of paint creates a thin, even layer on the canvas. Allow the second coat to dry to the touch, which will take about 30 to 60 minutes, before painting onto the canvas.
If you still see the original paint through the second coat, apply a third coat once it is dry
Part 2 of 4: Remove Acrylic Paint and Re-coat the Canvas Surface
Step 1. Soak the canvas in rubbing alcohol for an hour to loosen the paint
Find a container that is large enough to hold an entire canvas, and place it outside or in a well-ventilated area. Fill the bottom of the container with 1/4 inch (6 mm) of rubbing alcohol and position the canvas so that the painted side is facing down. Leave the canvas alone for at least an hour.
- You can also use turpentine or ammonia instead of rubbing alcohol if you like.
- If you don't have a container for the canvas, spray the rubbing alcohol along the paint surface using a spray bottle.
Step 2. Remove the canvas and scrape the paint off the surface with a putty knife
Wear rubber gloves and a mask when scraping the paint so you don't irritate your skin. Shake off the excess liquid and lay the canvas on a flat work surface. Place the putty knife along the edge of the canvas and slowly push it away from you to lift any loose paint off the surface. Continue scraping the paint until there are no thick, textured areas.
- Paint has probably stained the canvas, so it won't look perfect when you're done.
- Don't apply too much pressure to the putty knife or you could tear the canvas.
If you can't remove all of the textured paint, soak the canvas in rubbing alcohol for another hour and scrape again.
Step 3. Clean the rubbing alcohol with warm water and dish soap
Place the canvas in the sink and run warm water on it to get it wet. Apply a few drops of liquid dish soap to a soft brush and rub the canvas in circular motions. Apply light pressure to allow the dishwasher to penetrate the canvas, wiping away any alcohol residue, and loosening any excess paint. You will probably notice that the paint stains will become lighter on the canvas.
If the canvas won't fit the sink, you can also wipe the surface with lukewarm water with a rag to clean
Step 4. Rinse the canvas and allow it to dry overnight
Drop lukewarm water on the canvas surface to clean up the suds and dish soap. Once you've completely cleaned it, place the canvas in a warm area to let it dry. Let the canvas dry completely overnight before using it again.
- If the canvas won't fit in the sink, wipe it with a cloth dampened with warm water until clean.
- You can also place the canvas in direct sunlight to speed up the drying process.
Step 5. Paint a coat of acrylic plaster on the canvas
Mix the plaster with a stir stick and apply it to the canvas with a 2-inch (5.1 cm) natural bristle brush. Start in the center of the canvas and pass the plaster in a thin layer with horizontal or vertical strokes.
- You can buy acrylic plaster at an art supply store or online.
- It's okay if you still see some of the original paint through the plaster because you will add another layer.
- Mix a colored acrylic paint with the plaster if you want a different base color than the canvas.
Step 6. Let the cast dry for 20 to 30 minutes
Place the canvas in a cool, dry place and allow it to dry to the touch. Check how dry the plaster is by tapping it with the tip of your finger to see if it comes off the canvas. If your finger comes out clean after touching the canvas, you can proceed to the next step.
Hold the canvas up to the light to determine if there are any bright spots. If the canvas is shiny, it means that it is still wet
Step 7. Apply a second coat of plaster in the opposite direction
If you painted the first layer of plaster with horizontal strokes, use vertical strokes for the second layer. Continue painting over a coat of plaster to cover any areas you missed the first time, and make an even coat of paint. Once the second coat is done, allow it to dry 1-2 days before painting.
You can add 1-2 more coats of plaster if the original paint still shows through. Let each coat dry completely before applying the next
Part 3 of 4: Removing Oil Paint to Create a Blank Canvas
Step 1. Remove as much paint as you can with a razor blade
Put on a mask or respirator before scraping the paint, as it contains harmful particles. Hold the razor blade at a slight angle to the canvas and push it away from you to remove textured oil paints. Apply light pressure to scrape as close to the canvas as you can without cutting it.
- Never pull the blade towards your body so that it does not slip and cause a serious injury.
- You can also use a putty knife if you take a long time using the blade.
Step 2. Sand old paint with 120-grit sandpaper to remove texture
Use long strokes from side to side to scrape the paint off the canvas. Apply light pressure to the canvas to remove the paint from the surface more effectively, but not so much that it rips or rips it. Keep going with the sandpaper until you can see the blank canvas showing through the paint.
- Oil paint may have stained the canvas and won't come off completely.
- If the fabric is too flexible and you can't apply too much pressure to the canvas while sanding, lay wood chip boards or another flat surface underneath so you have a solid surface that you can sand on.
Step 3. Rub denatured alcohol on the canvas to clean up any paint chips
Denatured alcohol, also known as isopropyl alcohol, lifts up residual paint and cleans the surface so the plaster can adhere better. Wet the end of a cleaning cloth with denatured alcohol and rub the entire surface of the paint. Work in strokes from one side to the other to remove any paint or dust that is still on the surface. When you're done, let the rubbing alcohol dry for 10-20 minutes.
Step 4. Apply a thin layer of oil-based plaster to the canvas
Mix the plaster thoroughly with a stir stick, applying it to the best consistency. Start by applying the plaster in the middle of the paint and brushing it to the edges with a 2-inch (5.1-cm) natural bristle brush. Work in vertical or horizontal strokes until there is a thin layer of plaster over the entire surface.
- You can buy oil-based plaster at an art supply store or online.
- It's okay if you can still see the original paint through the first layer of plaster.
Don't use acrylic-based plaster over oil paints because it won't adhere to the canvas as well and could cause new paints to chip or easily peel off the surface.
Step 5. Let the cast dry to the touch for 20 to 30 minutes
Place the canvas in a place away from the sun while it dries. After 30 minutes, touch the canvas with your finger and see if any of the plaster lifts off the canvas. If the finger is clean, you can continue. Otherwise, allow the cast to dry longer.
Keep the canvas flat while the plaster dries to avoid droplets
Step 6. Apply a second coat of plaster in the opposite direction
Painting the plaster in a different direction will give the canvas a smoother finish and fill in missed spots more effectively. If you lay the first layer horizontally, then use vertical strokes for the second layer. Keep brushing on the plaster until there is a thin layer and you can't see the paint underneath. Let the plaster dry for at least 1 to 2 days before you begin painting it.
- If you need to apply more layers of plaster to hide the undercoat of paint. Then wait 20-30 minutes before applying another coat.
- You can't use acrylic paints on oil-based plaster, as it won't adhere as well and could cause the paint to crack.
Part 4 of 4: Flip the Canvas and Use the Back Side
Step 1. Remove nails or staples from the canvas frame to remove it
Flip the canvas over so the back of the frame is facing up and you can see the nails or staples holding the fabric in place. Hold the nails or staples with tweezers and remove them directly from the canvas frame. Keep removing any nails or staples until the canvas comes off the frame.
- This method only works with canvas stretched over a frame and does not work with canvas panels.
- Nails or staples may be on the sides of the frame rather than the back.
Step 2. Place the painting on top of the removed canvas with the painted side up
Lay the canvas out on a flat surface so that the painted side is facing up. Position the frame on the canvas so that the back is facing up, and align the folds of the canvas with the edges of the frame. Make sure the canvas lies flat on your work surface and has no wrinkles.
Step 3. Drive nails or staples into the center parts of each side of the frame
Start on one of the long sides of the canvas to make the process easier. Fold the edges of the canvas around the frame and pull it snugly over the back side of the frame. Drive a nail or staple through the canvas in the center of the side of the frame to secure it in place. Flip the frame and canvas over so you can nail or staple the other long side to pull it tight. Repeat the process on the 2 short sides.
Have someone help you by pulling and securing the canvas to ensure it is tight
Step 4. Stretch the canvas to pull it snugly into the frame
Start at the center of a long edge and secure the canvas to the frame every 2-3 inches (5 to 8 cm). Once you put in a nail or staple, add either one at the same point on the opposite side to make sure the canvas stretches evenly. Continue pulling the canvas tightly and securing it to the frame until you reach the corners. Repeat the process on the short sides to ensure that the front of the canvas does not have waves or wrinkles.
When you're done, the front of the canvas should look flat and move slightly when you apply pressure to it
If the front of the canvas has wrinkles or waves, remove the nails or staples and stretch it again until it looks flat.
Step 5. Apply layers of plaster to the unpainted side of the canvas and allow them to dry
Use an acrylic-based plaster if you want to use acrylic paints or oil-based plaster for oil paint. Begin applying the first coat of plaster in horizontal or vertical strokes using a 2-inch (5.1-cm) natural bristle brush. Once you have a thin layer of plaster, allow it to dry to the touch for 20 to 30 minutes. When the first coat is dry, you can place a second coat using strokes in the opposite direction of the first coat.
You can also cover the painted side on the back of the canvas with plaster if you want to hide it
- Work in a well-ventilated area while removing the paint so that fumes or particles don't collect in the area.
- Wear a mask or respirator while sanding or scraping the paint off the canvas, as the paint contains harmful particles.