Friday, February 19, 2016

Brushes Part 3 - Care and Maintenance

Part 3 of a series of posts dealing with brushes for oil painting.

After spending a substantial sum on a good brush, the skinflint in me demands that it last as long as possible. Given the potential damage that solvents, oils, paint, soaps and even water can do to brushes, learning to clean and store them correctly is critical. There are differences in effective care among the various kinds of artist brushes, mostly based on the type of fiber. Originally I learned to use natural hair brushes, so the first section below deals with those. In the following section caring for the synthetic brushes (which I use most commonly now) will be covered.

There are other ways to care for brushes which may have merit; these are the methods I use. These techniques have stood the test of several decades of brush care. Anyone who can improve upon them, please let me know what you do.

Care of Natural Hair Brushes
Natural hair brushes come in two general types: hog bristle and various softer hairs such as red sable, true sable, badger, and others, even squirrel. Both types of natural hair should be treated similarly, although a few important differences do exist.

First, a word about using one's brushes. Proper use of brushes can extend their life substantially. Here are a few important principles:
  • In general, load only the tip of the brush, dipping into the paint no higher than about halfway to the ferrule. This helps to keep paint away from the ferrule; dried paint will ruin a brush by destroying elasticity and causing the hairs to become brittle and break.
  • Try to use separate brushes for separate colors and again, load each sparingly. It will mean more brushes to wash but they will be easier to clean and can last longer.
  • Don't use too much solvent. Some people paint a stroke or two then rinse the brush thoroughly in mineral spirits. In my experience this can be harmful by needlessly exposing brushes to chemical injury. Instead, I wipe paint from the brush between strokes and rinse infrequently since I use one brush for one color. 
  • Never let paint dry in your brushes.
  • Wash brushes immediately after each painting session. If you can't wash them with soap then at least wipe and rinse them to remove most of the paint. Don't delay washing longer than overnight.
  • Consider using linseed oil soaps and hair conditioner on natural hair brushes to maintain their resilience.  
Bad brush care can make yours look like the ones in this
"Old Friends," watercolor, 2002. (Private collection)
watercolor I painted a few years ago. These were from a photo reference, in case anyone wonders--they certainly don't reflect how I treat my own brushes.

Hog bristles
These brushes should be wiped clean of paint at the end of the day's painting session, in particular squeezing the belly of the brush to force paint out of that area and out the tip of the brush. I generally use paper towels, but reusable cloth rags are more environmentally sound. Once the paint is out of the brush, rinse gently in mineral spirits as needed, squeezing out remaining dissolved paint. (The variety of mineral spirits doesn't really matter, though the odorless kind are more pleasant to use. A close friend of mine still advocates the use of kerosene, which is a kind of mineral spirit as well. Kerosene is the old friend of the sign painters of days gone by.) Brushes should be rinsed and wiped until you don't see any color come off onto the rag. You don't have to get every last particle of color out of the brush since you're going to wash it in soap and water anyway, but try to get as much out as possible. Be sparing with solvents. While natural hair will stand up to solvents pretty well, overusing them can cause damage. After rinsing, I wash this kind of brush in lukewarm water, using a good brand of cake soap, preferably. Hot water should be avoided since it will supposedly take the snap out of hog bristle, making them limp and less useful with thick paint. I don't wash bristles in hot water so I can't vouch for the accuracy of the warning. On the other hand, washing them in cool water seems to work fine. Ivory is my soap of choice, but many use special brush soap made with linseed oil. (Soap is compounded from a fat or oil plus an alkali like sodium hydroxide. Soap made with linseed oil will supposedly penetrate and clean oil paint from brushes more easily and thoroughly.) Whatever soap you use, work up a lather, wiping after each repetition then re-lather and wipe again. Wash for at least 30 seconds while working the soap/paint lather out of the brush. When no more color comes out, rinse with cold water and reshape bristles as necessary to their original shape. Saliva helps--lick your fingers. Flat and brights shapes have a slightly turned-in corners; filberts have elliptical, flat tips, and rounds are...round but come to a point. Many painters today also add a conditioner during the shaping step, similar to what people do after washing their own hair. Conditioners restore a bit of softness and springiness. Store brushes tips up in a cylindrical container--vase, coffee can, whatever--and allow to dry.

Soft Natural Hair
Like bristle brushes, this kind should be wiped of any residual paint, squeezing it from the belly as well. These brushes can stand up to mineral spirits, even kerosene, but in the case of more delicate or expensive brushes, I use gum spirits of turpentine, which seems gentler and is a good solvent. Turpentine can be used sparingly with good results. My technique is to make certain I've wiped out as much paint as I can, then dip the brush in turpentine, work a bit into the fibers, wipe again, repeating until nearly clean. In my experience, turpentine is more gentle than mineral spirits. Regardless, all brushes must also be washed, and again many use a linseed oil-based soap--there are a number on the market--plus a conditioner sometimes as they reshape the hairs. Washing is done similarly to bristles, working up a lather for 30 seconds, wiping, repeating until no color returns in the lather. Warmer water can be used than with bristle brushes but there's no real point in doing so unless you need a measure of softening to get paint out of the hairs. These brushes are best stored standing up until dry.

People sometimes wonder why a brush would dry better standing up, and honestly it beats me. Maybe they would dry as well lying flat. Many have said that capillary action helps in drying, which may be so, but capillary action works regardless of position. Capillary action occurs when a fluid flows from one end of a small-diameter tube to the opposite owing to the surface tension of the liquid and the adhesion forces against the tube. Position has no role. Capillary action is strong enough to raise liquid in paintbrushes against the pull of gravity, thereby keeping the ferrule more dry, but since this action can occur regardless of position, perhaps storing brushes tip-down, so that gravity aided capillary action, might keep the ferrules even more dry.)

Care of Synthetic Fiber Brushes
Most synthetic brushes these days seem to be made from nylon but there are a number of polymers out there and a number of proprietary names that are used. This is what I currently do with my synthetics. My current brand is Silver Ruby Satin but I also recently began to use some brushes made with Golden Taklon. I can't vouch for the effectiveness of this care routine for any other brushes except these.

At the end of the painting session, wiping and removing thick paint should always be first. Then a rinse or two in mineral spirits. Some painters seem to use a lot of mineral spirits during painting and I suspect that causes significant wear and tear on many synthetics. If you paint with a lot of such thinner, maybe these kinds of brushes aren't for you. A friend of mine, using the same kind of brushes as I do but with considerably more OMS rinsing has found that they splay and become unusable in a relatively brief period. Using considerably less OMS seems to preserve my own synthetics. In any event, I next wash the brush in plain soap and hot water, which does little to synthetic fibers of the two types above. These generally resume their shape quite well and dry very quickly standing up. Obviously no need for conditioner!

Salvaging brushes:
Sometimes a painter forgets a brush or two, maybe even leaves them without cleaning so that they've become hardened with paint. Good brushes are expensive. What to do?  Like so many things, it just depends. If the brush is hard as a board, the paint stiff and dry, throw it away. On the other hand, if the paint is dry to touch but flexible and clearly not dry through and through, you may be able to get the paint out and salvage it. Here are a few ideas and tips.
  • If the brush with the semi-dry or dry paint is a natural fiber type, first try soaking in mineral spirits for a few minutes. This may soften the paint and allow you to wipe at least a portion away. Synthetics may also benefit, but beware overusing mineral spirits with synthetics.
  • If cleaning a natural fiber brush, work a linseed oil soap into the belly of the brush if you can, then coat the entire outside with the soap and allow to stand for several minutes to several hours. This may soften the paint and allow you to wash it away. (In most cases, linseed oil soap is soft enough to allow this.) Generally I use Ivory to clean synthetics.
  • If you've been able to remove a substantial amount of paint by soaking but areas of dry paint still adhere to the fibers, try using linseed oil soap (for natural fibers) or Ivory (for synthetics) while scrubbing along the length of the fibers with a fingernail brush. These can be gotten from drugstores or cosmetics companies and have short, stiff bristles that can get between the fibers and scrub off flecks of dry paint. If this step fails, the brush probably can't be gotten more clean.
  • You can sometimes reshape skewed or splayed synthetic fibers by dipping them in boiling water and then reshaping. Natural hair can be reshaped while wet and then splinted using stiff cardboard (bristles) or a sizing agent (softer hair), although I don't use either trick.
Finally, even if you can't get out all of the paint, or the brush is splayed or bent or whatever, you might still keep it around for use in blending and in scrubbing layers. For that kind of activity, these sorts of derelict brushes can be ideal, and so you can get a bit more mileage out of them. 

For a good guide to brushes and their care plus considerably more and for substantially more expertise than mine, my favorite book is "Brushes" by Jacques Turner, published in 1992 and widely available online.

Brushes Part 1
Brushes Part 2 

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