Stain Colors
First and foremost, the most obvious quality of any stain is color. Chances are, the last stain you may have chosen was because of the color – not because of its chemical makeup. But not understanding the differences in stains and how each wood takes stain can lead to problems later on down the road. Most failures in staining come from the wrong choice in stain rather than the wrong application.
The first thing to understand about staining wood is applying the same stain to both maple and walnut will result in a different color. Something else to understand is that stain acts differently on solid wood than it does on veneer. Typically, solid wood will stain a bit darker than veneer will. So, what qualities do we look for in choosing the right stain? Colorant, amount of colorant, binder, thickness, and the chemical makeup.
Pigments & Dyes
Stains are made with two different types of colorant: pigment and dye. Pigments are made from finely ground earth. The “earth” can be natural or synthetic. Until recently, they were all actually made from finely ground colored (real) earth that was mined in various locations throughout Europe and North America. Nowadays, most pigments are made from synthetic materials. Pigments are opaque and for this reason they are used in paint coloring. Because they are more dense than the liquid they’re suspended in, they settle to the bottom and have to be stirred frequently. When stain is applied to the wood, pigments lodge into small holes like pores, scratches, or gouges. This is a great example of why we sand with the grain! You can also build the thickness of pigments to make it act like a paint. Rather than wiping all the excess off, building requires some of the excess to be left on the wood. It kind of acts like a thinned down paint.
Dyes are colorants that are often found in coffee or walnut husks but are also made from synthetic materials that are of much better quality. The synthetic dyes are made from petroleum and were originally developed for use in textiles. In wood finishing, there are four types of dyes: water-soluble dyes, alcohol-soluble dyes, oil-soluble dyes, and non-grain-raising (NGR) dyes. The first three are typically sold in powder form while NGR dyes are sold in liquid form. Water-soluble dyes are the best to use on cabinetry and furniture when applying with a brush or cloth. It has a longer “open” time which means you have plenty of time to wipe all the excess dye off. Alcohol-soluble dyes are used mostly for touch-ups and are brushed on to damaged areas. Oil-soluble dyes are used as a colorant in oil and varnish based stains and are rarely used on their own to color wood. NGR dyes are used when spraying directly onto the wood and leaving it or in combining dye with finish to make a toner.
Dyes are made from a chemical that dissolves in a liquid. When looking at the stain, everything that has settled to the bottom is the pigment and everything that remains in the liquid is dye. In woodworking especially, pigments tend to only fill pores large enough to hold it when the excess is wiped off and dyes penetrate the woods surface entirely. When the stain is left on the wood, pigments tend to conceal the wood when left on and dyes tend to be transparent. Unlike dyes, pigments must always be mixed with a “binder” to ensure its particles stick to the wood. Binders are a type of “glue” that holds pigment particles to the wood. If pigments are applied without a binder, when the liquid dries, the pigment particles can be blown right off the wood’s surface just like dust. There are four kinds of binders which include oil, varnish, lacquer, and water base. Sometimes Shellac can be used but a dye, such as alcohol dye or NGR dye must be added as a binder.
Applying Your Stain To Wood
There are two ways to apply stain to wood: apply wet stain and wipe it off before it dries, or apply the wet stain and leave it on. We typically reserve the latter option when using a spray gun. In wiping or brushing the stain on, the “wipe on, wipe off” application technique is preferred. As long as the wood has been prepared properly, this will help to achieve an even coloring. The main concern in wiping the stain and wiping it off is ensuring it is wiped off before the stain starts to dry. Some stains, like lacquer or solvent based dye stains tend to dry faster. Using these stains on a larger product may require having a second person to wipe off the stain as the first person applies it. Not to worry, though! If the stain blotches because it is not wiped off in time, just wipe a little more wet stain on to liquefy it again and wipe it off immediately.
Some woods, such as maple or beech tend not to take a stain very well and can turn out blotchy when stained. In these cases, it is important to treat the wood with a “washcoat”. Washcoats limit how much a stain can actually penetrate the surface of the wood. Applying a washcoat to these particular woods takes vast knowledge and experimentation to get it right. In larger, production jobs, it is certainly worth the effort to ensure the quality of the stain. However, in small, maybe one-off pieces, a gel stain will give a little more predictable finish without the extra hassle of perfecting the washcoat.
A Brief Guide To Wood Stains:
- Pigment stains – Any stain containing pigment. Pigments do not stick to wood on their own so a binder must be present in this type of stain. Many “so-called pigments” contain dye.
- Dye Stains – Stains containing dye. Dye soaks right into the wood with the liquid it is in, so no binder is necessary. Dyes, in addition to binders, are also added to pigment stains. These particular stains are referred to as pigment stains and not dye stains.
- Wiping Stains – Contain pigments, binders, or both, and all contain a binder. That helps the pigment stick to the wood. These dry slowly enough that wiping off can be done in a more laid back manner. Most consumer stains are wiping stains.
- Oil Stains – Any stain that oil acts as a binder. They can be pigment, dye, or both types of stains.
- Water-Based Stains – Any stain that contains a water based binder. They can be pigment, dye, or both types of stains.
- Varnish Stains – Any stain that contains a varnish binder, whether pigment, dye, or both.
- Lacquer Stains – Any stain that contains an alkyd varnish or lacquer binder. These dry very fast and are intended for spray applications.
- Gel Stains – Thickend stains that don’t run. It stays at the surface of the wood and only contains pigment.
Stay tuned for more woodworking tips, tricks, jigs, and techniques coming soon. In the meantime, view some of our recent work in our gallery.