How to Paint Over an Unfinished Oil Painting

Do you have an old canvas that you'd like to paint over or continue working on? While it may not be ideal for every oil painting, it is possible to reuse or revitalize a work in progress even if it's been in storage for years.

Many artists choose to paint over an unwanted and unfinished oil painting. This can save on the cost of a new canvas and the time involved in stretching and preparing it. It is also a nice way to practice a new technique or work out ideas without investing extra cash. However, there are a few considerations that you should take into account first.

Should You Paint Over an Old Oil Painting?

You can paint on an old oil painting like it is a new one, you will just need to make sure there is no grease or dust on it. However, you might want to consider if it's worth the effort. Would it be easier or the final painting better if you simply begin with a blank canvas?

Ask yourself this: Is it worth the slight risk that the old paint may show through? It is also possible that the new painting may crack because the painting underneath pulled in all of the oil. Is the money you're saving by reusing the canvas worth it?

Many artists would probably answer "no" to these questions and move on to a new canvas. At the very least, you can use those unfinished canvas pieces as a study for the new painting. What went wrong? Why did you abandon it? What do you like about it? Use this as inspiration and learn from what you did in the past.

If you do choose to start anew, think about recycling the stretcher bars for your new canvas. Carefully remove the old canvas and store it if you like, but those stretchers should be good for another go around and simply need a fresh piece of canvas.

Of course, there are artists who actually seek out old paintings when creating a body of work. Artist Wayne White is a perfect example and his colorful word paintings are created on top of thrift store paintings. The documentary film "Beauty is Embarrassing" showcases his work and artistic process.

Most artists will not take White's approach though and if you do want to paint over an old canvas, there are some tips you will want to know.

How to Paint Over an Old Canvas

There are two basic ways to approach an old canvas: start all over or work with the paint that's already there. The trick to either is to ensure the canvas is clean before you begin.

Many old paintings that have been stored for years are dusty, dirty, and some even get a little greasy.

• Dust can be dealt with by wiping the painting with a damp cloth and leaving it to dry.
• If there's any grease on the painting, wash it lightly with a solution of rubbing alcohol and let it dry overnight. You can then paint on it as usual. 

Be sure that you don't overwash it. What you don't want to see is any paint color on your cleaning rag. This is a sign that you are cleaning it too much and getting into the paint layers rather than removing the dirt on top of it.

Once the painting is dry, you can either continue painting or begin to cover up or remove the old layer of paint.

• If the colors on the old painting are very intense, consider painting a layer or two of fat titanium white (not gesso) on top. Allow it to dry completely between coats.
• If the painting has any unwanted texture or impasto work, you will need to sand that down. Use a fine grit sandpaper and gently remove the 'offending' paint. Wipe the canvas with a damp cloth and allow it to dry before adding those fat layers of titanium white.

How to "Wake Up" an Old Oil Painting

There may be an old canvas painting that you really do want to finish, even if it's been years since you first touched it with a brush. It's very easy to get it to a workable state by giving it a "wake up" - the technical term is oiling out.

1. Begin by removing all of the dust and grime with a damp cloth and allow the painting to dry completely.
2. Apply a thin coat of oil medium and allow it stand for at least a day (choose a location where it's not going to gather dust).
3. You should be set to begin painting again.

Remember, that the new oil paint you will apply has oil in it which will also 'feed' the old paint. That is why only a very thin coat of medium is required.

On an interesting and related side note, some Old Masters used a thin "wake up" layer between dried coats while glazing. You might want to consider trying that sometime as well.

Originally Written by Gerald Dextraze, August 2006