If you’re like me, you have at least two paintings lying around somewhere that will never be finished. They started out with a grand and glorious idea, but went astray somewhere.

You hate to throw that panel away because you paid good money for it. But you have no idea whether or not it’s safe to paint on or how to prepare it if you do decide to paint on it.

Today, I’m going to share with you one way I prepare a panel for painting after a painting has already been started on it.

The panel I am using for this demonstration is 24 x 30, 1/4-inch Masonite. Smooth on one side, rough on the other. The panel was originally prepped with a minimum of three coats of acrylic gesso. My goal is not to get all the way back down to the gesso, just to remove as much of the several layers of paint as possible.

If you don’t have a circular or orbital sander (and I don’t), the first step is to scrape the panel with a single edge razor blade. Use caution! These things are sharp!

But they work wonders on a painting whether you’re removing large or small areas of work.

Hold the blade with the cutting edge flat against the panel to avoid gouging the panel. (The corners of the razor blade can be rounded if you prefer, but this is not necessary). Pull the blade across the surface with medium pressure (about a five on a scale of one to ten, with ten being the heaviest). Work over the areas where the paint is the thickest, but don’t ignore the other areas.

Work in several directions, too. Side to side across the painting. Up and down. Diagonal. The result will not be an eggshell smooth surface, but it will produce the smoothest surface possible.

Because this is physical work and tiring for hands, wrists, arms and back, I alternate scraping and sanding by scraping a small area, then sanding it.

I used to use sheets of sand paper, then a few months ago I was in the hardware store and found sanding blocks. What a great invention!

This (above) is a “fine” grade sanding sponge with sanding surfaces on both sides. It can be washed out and re-used, so has quite a long life span. The cost was comparable to five sheets of sanding paper. They come in various grits and for various surfaces. This one is actually a wedge shape for getting into corners, but it works great for sanding used paintings, too!

The sanding technique is a lot like the scraping technique. I work in alternating directions, turning the panel frequently so the sanding is as even as possible.

I also use a circular stroke quite a bit to eliminate any lines that might remain of previous brush strokes or from other sources.

As already mentioned, the goal here is not to remove every bit of paint and get all the way down to the gesso layers. If I had an orbital sander, I could do that. I have had panels sanded all the way through the gesso and down to the original Masonite. That is a great way to recycle a panel, but it also requires a power tool and a reasonable amount of dexterity. I have the dexterity. I don’t have the power tool!

What I am looking for is a surface that is even or has just the right amount of texture. If you are going to be painting with thicker paint and using impasto passages, you could get by with a more lightly sanded panel. If you’re doing detail work, you will want as smooth a surface as possible.

Once the panel is completely scraped and completely sanded, wipe it off with a clean rag or paper towel. Make sure to dispose of these properly, as well as the shavings and dust.

There will potentially be a lot of shavings and dust, so be prepared. Work in an area that is well ventilated and it’s a good idea to wear a mask over your nose and mouth. I usually do this type of work outside the house to avoid leaving shavings and dust around the studio. If you have to work inside, a vacuum cleaner is invaluable for picking up the remnants of your work.

This only works with rigid supports. There are ways to remove old paintings from canvas (yes, even stretched canvas), but the kind of rigorous treatment I gave this panel would grind a hole in a stretched canvas! You don’t want that!