This is another project where I am finishing first and assembling the completely finished pieces. This avoids issues with glue squeeze out and having to sand inside corners (which I hate to do). By finishing first, I can also spray the finish coats on while the pieces are horizontal , which mitigates my uneven spray gun strokes and resulting runs. It also makes the application of the stain easier as there are no inside corners to deal with.
Cherry wood offers deep rich color and fine grain patterns. However it has some quirks that must be dealt with. The wood can change color dramatically over the years. Initially it darkens for the first 2-4 years. After 20-25 it lightens up again. The difficulty is that the degree of change can vary dramatically from one piece of wood to another. This can be mitigated by choosing wood that all comes from one tree, but this is impractical for the most part unless you are sawing your own. Next best is to cut as much as possible from a smaller number of color matched planks.
Staining can darken the grain, even out the color variation and mitigate some of the color changes. However cherry is also prone to splotching where the stain is absorbed very unevenly. This is due to the grain changing direction and it is often not easily discerned of an are will splotch prior to the application of the stain. In order to add color and mitigate the splotching issues, I use a multi-step finishing process. The major steps for adding the color are:
Spray alcohol based dye. I use Transtint Red-brown for the cherry. It is diluted to the manufacturer’s directions in denatured alcohol. This is sprayed on in 2 very light fine coats. I use a DeVilbiss Plus high transfer efficiency gun with a 1.2mm nozzle. Allow the wood to dry thoroughly between coats (typ. 1 hour) The coats must be light to avoid puddles and bleed back from the wood pores as the alcohol evaporates. While this is not as much of a problem as with an open pored wood like Oak, it is still an issue to watch out for. One of the key things to remember is that as the alcohol evaporates the color WILL NOT look as even as it did when wet. You MUST resist the temptation to “touch up” or otherwise futz with the finish at this point. I spray pairs of sides (front and top) and then flip the pieces and spray the opposite sides. Care must be taken that the stickers are completely dry before flipping or there will be unsightly splotches where the wet spots contacted the already sprayed surfaces.
Spray wash coats of shellac. I use Ruby shellac flakes mixed to a 1-1.5lb cut. This is sprayed on in the same manner as the dye. Very light coats are required to prevent splotching of the dye in puddled areas and bleed back.
Typically it takes a day to get the coats of dye and shellac applied to all sides of the pieces. Once the shellac has dried it is time to apply the stain. Prior to staining, you may want to lightly scuff the surface with a maroon Scotchbrite pad. However, the shellac went on nicely and I have no “shiny spots” to deal with. So this time I was able to skip that step.
The stain I am using in this case is General Finishes Gel stain. In order to color match the other pieces of furniture I have made for Jessie (Isla’s mom), I need to mix 2 parts of Georgian Cherry and one part Candlelight. The stain is wiped on, rubbed in and the excess is wiped off.
As you can see in the photo above, the stain enhances the wood grain and deepens the color. The piece in the back has the dye and shellac applied. The piece in the foreground has the dye , shellac and gel stain also applied. As you can also see in the photo the center appears lighter than the edges. This is one of the benefits of the dye + colored shellac + stain process. As you change the viewing angle, the brightness and coloration change is enhanced vs simply having the stain alone. This is referred to as the chatoyance of the wood. A piece with lots of chatoyance will appear much more “lively” to the viewer than one without. One of the reasons for the success of this process is using the colored ruby shellac, as this will exhibit the effect much more strongly than white or amber shellac.
With the dark gel stain, moving the pieces to a location to dry can be problematic. Keep multiple rags to grip the piece with and wipe over the areas where gripped to avoid light colored finger prints. At the end of the staining session it is also recommended to look over all of the sides of all of the pieces to check for dark splotches where the stain may not have been wiped off properly. I set the pieces nearly vertically along the perimeter of the shop. The goal is to provide air circulation and not mar the freshly stained surfaces.. Now the pieces are set aside to dry for a couple of weeks. I use a water based polyurethane – General Finishes Endurovar in the winter as I can carefully spray it indoors without risk of explosion. As you might expect, oil (stain) and water (finish) do not mix or adhere when wet. The long drying period ensures the oils have either evaporated or cured so that the piece is ready for the clear coat finish. If you are using an oil based finish, 2-3 days is still recommended to avoid picking up the stain as you apply the finish. In warm weather I will often use a precatalyzed lacquer finish.
A note about denatured alcohol
It is getting increasingly hard to get “good” denatured alcohol with a high percentage of ethanol. Much of what you will find at the big box stores and hardware stores is labeled as denatured alcohol “fuel”. You should take that as a warning sign for a product that has a high percentage of methanol. Not only is methanol quite toxic, it is also a poor solvent for shellac. When dissolving shellac flakes in a high methanol alcohol you will end up with a gummy lump in the bottom of undissolved flakes which may be 20% of your shellac. It pays to look for high ethanol concentration denatured alcohol. You can tell the difference with those that are labeled for diluting shellac (as at a dedicated paint store) or by looking up the MSDS and checking for at least 75 % ethanol if not higher. Some of the “green” or “natural” denatured alcohol products fit in this category but remember that these terms have no real meaning – check the MSDS. If in doubt, you can always go to the liquor store and get Everclear, but you do pay extra due to the liquor taxes.