What Is Milk Paint?
Milk paint is a highly durable, breathable coating that never peels or chips. Unlike conventional topcoats and oil-based paints, it is absorbed deeply into the fibres of the wood. This paint’s basic ingredients include milk, limestone, clay and natural pigments such as berries, seeds, minerals and coal. Because of this, it is non-toxic, non-polluting and is virtually fume-free. On the downside, because it has a natural milk base, any unused product must be discarded after two days. Depending on how thickly it is mixed, it can be used as paint, a coloured wash, or as stain. It is used by antique furniture refinishers and those with an interest in producing furniture that has a timeless look about it. There is a wide range of colours, all of which are colourfast (won’t fade) and which can be blended together to create a wider palate of colours. With all of this going for it, it’s not surprising that milk paint is making a resurgence.
Prepare the panel
Sand the panels starting at 100 grit through to 220 grit.
Mix the paint
An electric mixer is the most efficient way to mix the milk paint to achieve great results.
Apply a clear coat
You can apply the top coat of your choice – in this case, gel urethane is easy to apply and produces a great finish.
Before and after
You can see the dramatic difference between the milk paint and natural finish.
Like most finishes, milk paint requires that surfaces be prepared properly. However, because this paint gets absorbed so fully into the wood, surfaces need to be completely free of waxes, any other finish, and stain. Starting with 80 or 100 grit sandpaper, progressively work your way all of the way down to 220 grit. Lightly mist the panel with water to raise the grain and then cut the raised grain down with another light sanding, using 220 grit sandpaper. According to Loree Wallace of Homestead House Paint Company (homesteadhouse.ca), Canada’s leading producer of milk paint, there are certain special effects such as crackled or distressed finishes, which require these preparation rules to be broken.
Fortunately for us, manufacturers have made milk paint very simple to mix. Unlike our forefathers who had to gather all of the ingredients themselves, all we need do is simply add water to the powdered paint and mix thoroughly. Best results are achieved by vigorously mixing the paint using a high-speed mixer for 10 minutes, followed by allowing things to settle for another 10 minutes, then thoroughly mixing a second time. The paint will thicken considerable during this three-step mixing process. If it’s too thick, add water and mix again. Conversely, if too thin, add more paint powder.
Apply the finish in three steps, using a brush designed for water-based finishes. Your first coat will usually look quite faded and inconsistent, with pronounced leading and trailing brush marks. This is normal and is largely caused by the speed with which this finish dries, so don’t be discouraged. According to Wallace, many finishers prefer this effect and will often stop at this point and apply the protective topcoating. If you wish to apply a second coat of milk paint, wait until the first one has thoroughly dried to the touch then lightly sand the finish using Scotch Brite pads or 220 grit sandpaper and dry brush or vacuum off the powdered residue. Regardless of the number of coats of milk paint you apply, always work from wetted areas to dry ones and try to be consistent with the amount of finish laid down with each stroke. Because milk paint is a water-based finish, it will readily bleed into adjacent areas. To avoid this problem, try to paint components wherever possible prior to assembly. Where this is impractical, be especially vigilant and start first in transition areas, using only a very lightly wetted brush. Always pause to stir frequently, as the heavy pigments and natural fillers rapidly sink to the bottom.
Apply the protective topcoat of your choice. Hemp oil and also gel urethane (see ‘Red Oak Finish‘, Jun/Jul ’09, Issue #60) are highly used. Some finishers prefer beeswax, either on top of, or in lieu of the top coatings already mentioned.
Special Effects – Crackled Finish
To achieve crackled finishes, Wallace recommends the wood be stained first using a lighter shade of paint. Again, the stain is nothing more than thinned milk paint. Apply hemp oil or crackle medium, either of which will seal the first coat and prepare the surface for the next paint layer. Lightly distress-sand the dried finish, then go ahead and mix up a thick batch of paint, of a somewhat lighter shade than desired. Apply the paint quite thickly, noting that it will have somewhat dry, muddy sections that crackle. Pick away any obvious clumps that appear likely to fall off, then apply your final topcoating, which will both darken and stabilize the finish.
Once you’ve tried your hand at this traditional finish, you’ll be amazed how easy it is to apply and wonder why you hadn’t already tried it. Besides, what could be more Canadian than milk, eh?