Cleaning Sea Sand to Use in a Painting

"Do you have to clean all the salt out of sea sand before using it in a painting on canvas?" -- Tamara J.

As salt is corrosive, if longevity of the painting is important to you, then you'd want to rinse the sand with tap (fresh) water to try to remove as much of the salt as possible. It may seem tedious, but rather you're bored for a little bit than someone has a painting which develops a problem!

I contacted Golden's technical support experts for their tips.

Sarah Sands, Technical Services Supervisor, said washing salts and any mineral deposits from sand "would be highly recommended and is definitely the safer route to go.

"The main issue would be less about any direct corrosive effect of the salt, as far as I know, than the fact that acrylics remain quite porous on the microscopic level while salt would be permanently water-soluble. Because of that, moisture and high humidity, as well as the evaporation of other volatiles in the film, could cause the salt to migrate and effloresce on the surface. One can see examples of this with cement and masonry products, where salts are deposited on the surface through very similar means.

Michael Townsend shared some of his personal experience with beach sand: "First, realize that there are many kinds of sand, from volcanic to near glass. The key with a found raw material or textural element is to do what you can to get rid of any silt and organic material the best you can.

"My most recent experience was with some pebbles and rocks from a beach in northern Long Island, NY. There was a lot of 'stuff' in the bucket of rocks that wasn't rock! Salts is one aspect, the other is the organic materials that are intermixed with the sand. These kinds of contaminates might want to leech out into the acrylic medium and at the very least discolor it."

So how do you get the salt and other 'stuff' out of sea sand. Michael provides a general guideline:

• Gather about twice the amount of sand they think is needed for their project, and put into a plastic bucket.
• Get another bucket and fill with tap water.
• Slowly pour the sand into the water and stir it as much as possible.
• Pour water out of the bucket, and repeat this several times.
• Once the sand seems pretty clean, pour it out onto a sheet of plastic and allow to dry. If there are any signs of contamination left, keep washing until it is gone.
• After the sand is clean, it can be added into the acrylic.
• Golden's Soft Gel Gloss is a great medium to use for this, at about a 2:1 ratio of gel to sand. Make a small mixture at this ratio and then adjust levels based on the dry film. Don’t use the wet mixture as the guide, because there is a lot of shrinkage of the acrylic and more texture gets revealed after it completely dries.

It may be easier to source some river sand or builder's sand than washing salt out of sea sand, though sea sand with bits of shell does have a more interesting texture to it.

If you only want a little bit of sand, you can buy small quantities amongst craft supplies --- look in the sand painting section. Or consider using an acrylic texture medium that has sand already mixed into it.