Recipe for Limewash or Whitewash

Question

I'm curious if anyone on here has a recipe to create limewash/whitewash for indoor use on wood? I will be making a kitchen back splash (actually, the whole wall behind the sink/countertop) out of reclaimed wood and would like to whitewash over it so that it has the grain showing, is that translucent white, and is durable.

It appears that whitewashing over wood does not provide much water resistance, but I've seen some reports that you can create a more durable whitewash finish by adding a "binding agent." I have not found out what the best type of additive is for the binding agent or if it even does anything. I've read about adding molasses or linseed oil.

I'm not SUPER worried about water resistance since there will be a piece of painted/caulked trim directly in contact with the counter top so any standing water would interface with that and not the backsplash.

Recipes I've seen mainly consist of 1:4 Hydrated Lime to Water, some calling for a certain amount of salt.

Does anyone have a good recipe they've used for a more durable limewash/whitewash?

Answer 1

Common recipe

• 2 c salt
• 6-8 c slaked lime
• 1 gallon water
• Mix salt in water.
• In part of the water mix the lime until it's a stiff paste. Add water slowly. Think gravy. Making it thick initially keeps lumps from forming. Add the rest of the water.

Whitewash will look very thin on application. Multiple coats 1-3 days apart work better than single thicker coats. This allows the carbonation of the hydroxide to proceed. If done in warm dry weather, the use of a binding agent that slows drying is necessary, or misting the coat.

Recipe 2: This one is low in salt by comparison to most.

• 12 c lime
• 2 c salt
• 4 oz elmer's glue.

Recipe 3:

• 12 cups lime
• 4 cups salt
• 2 gallons water

For additional durability: ONE of

• 2 tablespoons powdered alum OR
• 1/2 cup hide glue flakes OR
• 1/2 gallon skim milk

I suspect the glue gives the best durability increase.

From de Gruchy's Lime Works

A Lime Whitewash / Colorwash Recipe

• 10 lbs St. Astier Natural Hydraulic Lime 2 (NHL 2)
• 2 gallons of water
• ¼ cup of casein powder dissolved in hot water
• ½ cup of Borax (Won't allow mold & helps repel insects along with the lime)
• 3 lb common table salt (Salt is proven to only be beneficial to lime whitewash to harden it. Don't use salt with any Portland Cement based materials.)
• ¼ teaspoon laundry bluing for extra whitening or approximately ¾ lb of iron oxide pigment for a color of choice.
• Add 1 oz Alum to help make the pigment become more colorfast

I've also seen 1-2% linseed oil added as a binder, up to 1/8 raw linseed oil for the liquid.

A whiter colour and increased mildew resistance may be added by adding copper sulfate. This does make the paint more poisonous in quantity.

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Traditional pre-made whitewash had fine chalk. (CaCO3) Since whitewash 'hardens' by Ca(OH)2 + CO2 => CaCO3 the addition of chalk reduces the amount of hardening needed. Too much chalk however and there's not enough binding to hold everything together. Chalk doesn't need to be roasted in its making so it's a lot cheaper.

Wikipedia https://en.wikipedia.org/wiki/Whitewash

Good article: http://pachamamatrust.org/f2/1_K/CBu_build/Se01_whitewash_KBu.htm

This latter mentions several other binders, and is oriented somewhat to conservation applications.

Answer 2

None of the recipes in my first answer are anything like permanent, but they answered the request for whitewash.

A better approach that will require a bit of experimentation:

A: Use paint as a wiping stain. This works quite well if your wood is smooth. Dip a rag into paint, and wipe on. Wipe off the excess. This method does NOT work well with rough lumber, as the rough stuff holds too much paint in the depressions.

If you use latex paint, it may raise the grain leaving a rougher surface. To prevent this wet the surface with a sprayer, allow to dry, and sand with 150-200 grit. Take off the raised grain. With some woods you may have to do this more than once.

As a kid my bedroom was done this way, using 1/4" G1S fir plywood as paneling. Grain showed through but it was overall close to white.

B: Start with cheap white paint, and dilute it roughly 1 to 1 with the appropriate solvent. Note that this will make the paint very runny. You will want drop cloths in place. Paint on. with a brush or roller. Use scraps from your project to test. Note that the appearance wet and dry will be different.

C: If you like the sparkly patina of whitewash (made by calcite crystals as it changes to CaCO3) then use one of hte white wash recipes above, and try diluting that with latex paint 1 part paint to 2-3 parts white wash.

D: Another way to stabilize whitewash would be to apply a coat of water soluble polyurethane varnish after. A semi-gloss or satin would give you a reasonable to clean surface.

Answer 3

I’ve had good results using oil based primer. Primer has more adhesion than paint. Thin it with mineral spirits (paint thinner) practice on dilution until you like the result.