When we have no other criteria to judge things on, we always select the cheapest product. Well, most of us do. Isn't it always true that once we know some things to look for in the products and services we purchase, we are all willing to pay more if there are benefits to the more expensive product. This is always the case with the lowly paint brush. I have done it myself. There I stand in front of a rack of paint brushes, they all look pretty much the same to me sitting their in their packages and priced from $1.99 up to $24.99 ... so, what do I do, I purchase the cheapest one.
Then when I get home and start clear finishing my woodworking projects and find that I am really making a mess of an otherwise great project, and something I spent a lot of time making, and how the finish I am putting on is looking like crap. What's the first thing I blade ... the can of finish. BUT little did I know the real culprit was ME by selecting a cheap paint brush in the first place.
I can honestly say that when it comes to purchasing paint brushes, the more you pay the better quality you are going to get. But like all things, when you are armed with knowledge it makes all the difference in the world, and so ...
All paint brushes are either Natural Bristles or Synthetic Bristles. Natural bristle brushes are easiest to talk about because most of the material they use in these are things like Ox or Boars hair. The thing to remember about natural bristles is that when they get wet with water, they absorb some of that water just the same way your own hair does when you are in the shower. The problem with natural bristle brushes is the same problem you have with your hair when it is wet, it sticks out all over place and is hard to control. This same thing happens with natural brushes. This means that part way through painting a woodwork project with a natural brush using a water based product, at one point the bristles will start sticking out and spaying. When this happens it is all but impossible to get a good finish on any woodwork project. The next problem comes when you try to clean these natural brushes with water again the bristles continue to splay and in many cases even after drying they are never the same. Rule number one NEVER use a natural bristle brush with water based products. They are to be used only with oil based products or products that require paint thinner or var-sol to clean.
That takes us to the synthetic brushes, these brushes ARE OK to use with water based products, AND due to many changes and updates in manufacturing, most of the better quality synthetic brushes also do a great job of finishing when used with oil based products. Aside from the type of bristle, the next thing to look for is the "flagging" on the tips of the bristles. Budget paint brushes may have a tiny bit of flagging or none at all on the tips of the bristles. A good quality paint brush will have long flagging on the tips. This flagging is basically the "split ends" of the paint brush. Having a paint brush with long multi split ends is good! This is because it is these split ends or flagging that helps meld the finish together as it is being applied. When you don't have this melding of the finishing what you end up with is furrows of finish that looks like long streaky paint strokes. In most cases these streaks will not blend together after they are applied, they will sit their and dry as ridges of finish on your project.
No article on paint brushes can go without at least mentioning foam brushes. When these were first introduced many years ago they were touted as the best brush to lay down clear finishes as they left no streaks. That is true, unfortunately whey they do leave behind is air bubbles because foam is FULL of air and the more you "paint" with it the more air bubbles you get, and just like the streaks, these will not not away, instead as they dry and "pop" they leave little craters all over your work, again ruining a perfectly good finish. It is possible to lay down a finish with foam brushes but to do this you need to totally "load" the foam and not use it as a "brush". The problem with his is drips, waste of finishing material, and again, often less than desirable results.
At the end of the day, if you want a great finish, you need to start with a great brush, and when you are finished with that brush you need to clean it WELL and store it back in it's original cardboard package or wrap it in something like newsprint so the bristles will continue to hold their shape and be ready for the next finishing job. Good finishes require good tools and good finishing products and your paint brush is critical to getting good finishes.
Copyright Colin Knecht