Greetings from Bill Boxer, Sr. V.P. Apollo Sprayers, Int’l
Recently in an interview reflecting on Apollo's 50th anniversary I was asked if I remember any unique applications that might be beyond the standard and conventional applications for an Apollo HVLP spray system. I remember a few unique situations.
We sprayed liquid chocolate to ice a cake. We sprayed a rack of white buttons with a dye to satisfy short runs of special colors. And of course, Apollo HVLP spray systems are used to apply a sunless spray tan most successfully. One application that stands out to me is an artistic one.
I was in Medellin, Columbia, South America to work with our distributor on industrial applications for Apollo HVLP. He surprised me by driving to a skateboard park in a local neighborhood.
Skateboarders and bikers were exhibiting their trick skills in a beautifully painted skateboard bowl. A local artist had used an Apollo HVLP spray system to paint all the graphics beautifully displayed in the skateboard park.
Looking ahead to our 51st year I want to share with you a new HVLP paint spray system recently granted design and application patents. It is part of our Precision Series and known as the Precision-6. While this might not be your everyday spray system it is always nice for our readers to know what we are up to.
This unit builds upon the success of our popular Precision-5 HVLP spray system by offering 30% more power/pressure through Apollo's power boost technology. This now opens additional markets and applications to apply coatings that could not be accessed previously by any HVLP spray system available. I share this with you as you might know, or come upon someone who has need for the benefits of HVLP who might not be aware of this unique paint spray system.
Apollo Sprayers Inc. looks forward to more years of innovation, manufacturing and selling HVLP spray paint technology across multiple markets and around the world.
Color Your Wood
By Carl Duguay
While just about all wood species are beautiful in their own right, not all the pieces of wood we work with are perfect. Sometimes they need a bit of color. Few of us have the luxury of purchasing the lumber from a complete log. Normally we pick and choose through various stacks of lumber looking to acquire boards that match reasonably well in grain and color. Sometimes we end up with boards that have a bit too much sapwood in an otherwise field of darker heartwood. Or, we may have the budget for red oak, but the vision of walnut or mahogany. In cases like this, when the appearance is less than harmonious, we can choose to color the wood to even out those variations. Stains and dyes are the two most common ways of coloring wood.
Choosing a stain can be a confusing experience, as there are numerous types of stains and quite a few different manufacturers. In a broad sense, a stain is any liquid that contains a colouring agent (a pigment, a dye, or a combination of the two) and a binder that bonds the pigment or dye to the wood. Pigments are finely ground insoluble natural or synthetic materials suspended in a binder, which is why they typically settle to the bottom of the can of stain. Dyes, on the other hand, are coloured soluble substances that dissolve in the binder, which is why you don’t get any goop at the bottom of the can. Synthetic dyes are referred to as ‘aniline dyes; they use solvents rather than binders.
Pigment stains remain on the surface of wood, lodged in pores and surface scratches, while dyes saturate wood fibres. Dye stains come in a much wider range of colours than do pigment stains, and they are more uniform in colouring wood, but they fade much more quickly in direct sunlight than do pigment stains. Stains that contain both pigments and dyes obviously benefit from the qualities of both. In most hardware and home improvement centres you will find oil stains, varnish stains and water based stains. Oil and varnish stains also come in a ‘gel’ formulation, which contains a substance that resists flowing.
On a lot of projects woodworkers use the same wood species in both a solid wood form and as a plywood. Cabinet sides, shelves, and doors are often made of plywood, with the framing done in solid wood. Typically any exposed edges of plywood are covered with solid wood edging. Again, this can pose a problem when applying a stain. The veneer on plywood is very thin, so thin on some brands that you can easily sand through the top in a matter of seconds with a random orbital sander. The veneer is usually rotary cut (sliced off the log as it rotates on a lathe), and then glued, heated and pressed onto the plywood core, and finally sanded. Not only will the wood fibres be crushed, it stands to reason that some of that glue will migrate to the top surface of the veneer. It’s no wonder that the plywood will take stain differently than the solid wood.
Proper sanding of both solid wood and plywood is a key to achieving optimal results when staining. Make sure that you do a final sanding by hand, in the direction of the grain. Shine a light across the surface of the wood at a 45º angle; it will help you see any imperfections that need attending to. On coarser open grained species (like ash or oak) you can sand up to 180 or 220 grit, but on close tight grained species (such as maple and cherry) sand up to 120 or 150 grit. If you sand these woods too smooth they will have difficulty absorbing the stain.
Pay special attention to end grain. The deep open pores provide cavities for the stain to lodge, which is why end grain usually stains darker than face or edge grain. You can reduce this by either sanding the end grain much smoother (which burnishes the pores and reduces their ability to absorb stain), or you can apply a wood conditioner. It’s also important to remove excess glue completely, particularly around joints.
It’s good practice to make sample boards (from cut-offs of the solid wood and plywood from the project) to test the stain that you plan to use. If you anticipate using the same species of wood and colour of stain again, record details on the back side of the sample boards and retain them for future reference. It’s very discouraging to discover that the stain you just applied to a finished project is much too dark. If it’s a pigment stain you’ll likely have to sand down to bare wood in order to apply a lighter stain (or live with the darker stain). If you used an aniline dye you can easily lighten the stain by applying its solvent, even after the dye has dried.
Some woods, such as pine, cherry, and birch, are blotch prone - they absorb stain unevenly. There are two options to deal with woods that blotch. My preference is simply to use a gel stain. These thicker stains don’t penetrate wood grain as much as thinner liquid (oil or water based) stains. The second option, which you can try if you choose to use an oil or water based stain, is to apply a wood conditioner before staining. The wood conditioner will help the wood absorb the stain more evenly. Be generous with the conditioner, and remember to wipe it off before it dries on the wood.
Stains can be applied with a paintbrush, foam brush, by rag, or spray. Liquid stains, particularly water based stains, dry fairly quickly, so on large surfaces you want to maintain a wet edge, to avoid lap marks. If they do occur lay on a second coat of stain after the first one has dried. Of course, the best way to avoid this problem is to spray on the stain. On any project that will likely be exposed to direct sunlight, use a pigment stain – it’s much more lightfast. For projects that require vibrant, bright colours, or where you need to match an existing stain as closely as possible, use dyes. Any stain will result in a darker colour if you leave it on longer, or if you re-apply it after the initial stain has dried.
While I’ve used a wide variety of stains from a number of companies over the years I now use gel stains almost exclusively. I like that they don’t run, are very easy to apply with a rag, and don’t dry too quickly. And, they come in a wide variety of colours.
But don’t take my word for it; you really need to try several different stains to find one that suits your needs. Most are available in half-pint sizes for around $5 a can. Once you’ve latched onto a stain that you like, experiment with it on the woods that you typically build with. Try different finishes on top of the stains as well.
You wouldn’t expect to cut perfect dovetails the first time you try, so you shouldn’t expect to get perfect staining results without some practice. But you will be surprised just how easy it is once you’ve invested a little time in honing your staining skills.
A Question from a Reader:
Q: Can you explain the basic solvents and the purpose of each one?
A: The following is a basic understanding of the common solvents available in paint stores and home centers.
Mineral spirits (paint thinner) and naphtha dilute and clean up oils and varnishes, including oil-based polyurethane varnish. Neither of these solvents damage any fully dried finish, so you can safely use them for cleaning—that is, removing grease or wax.
Denatured alcohol thins and cleans up shellac. This solvent will damage a dried shellac finish almost instantly and lacquer and water-based finish fairly quickly, so be very careful if you use alcohol for cleaning.
Lacquer thinner and acetone thin and clean up all solvent-based lacquer products. These solvents can damage all wood finishes, so don’t use them for cleaning.
Super lacquer retarder containing butyl cellosolve, also called ethylene glycol mono-butyl ether or “EB,” evaporates very slowly, so it can be used to slow the drying of lacquers, shellac and water-based finishes. But use very little (less than 5%) or the finish may take days to fully dry.
Toluene (tolulol) and xylene (xylol) have very little use in wood finishing, though they can be very effective for cleaning grease from metal.
Take a Break and Have Some Fun!
See how many words you can find. Look for words horizontally and vertically. You can print this page, including the puzzle, work offline, and then highlight words as you find them.
Color Your Wood