As highlighted on our Furniture Finishing Process page, we primarily use Rubio MonoCoat to finish our furniture and art pieces. For indoor furniture we specifically use RubioMonocoat Oil Plus 2C (they offer different product variations for indoor, outdoor, and other applications). For outdoor pieces we specifically use Rubio MonoCoat Hybrid Wood Protector.
Appropriately Sand Surfaces
The first and most time consuming part of finishing a piece of wood is properly sanding and preparing the surfaces. Typical workflow will be using a random orbital sander, and sanding each grit (80 grit, then 100 grit, then 120 grit, then 150 grit, then 180 grit, then 220 grit, etc.), without skipping grits in between. If you try to jump grits (such as sanding at 80 grit and then jumping straight to 150 grit) you will notice tiny swirl or pigtail marks once the product is finished. This is because each grit will work to remove the micro sanding marks left by the previous grit, and skipping through the grits will often result in those micro sanding marks not being properly removed. Moving slowly through the grit progressions above will take time, but will result in a superior finish when completed. The higher you sand your piece, the more the pores of the wood will be closed, as the fibers are sanded down finely. For the best proper molecular adhesion, Rubio generally recommends to apply Rubio MonoCoat to the wood after you stop sanding, somewhere between 120grit to 220grit (depending on the substrate). If you sand to higher grits than this the Rubio will have less open pore substrates to form a good bond with, and the hand feel at higher sanding is negligible for most surfaces anyway.
Sanding Tips and Technique
There are numerous sanding instructional videos on YouTube, but in general you want to move very slowly when sanding (think about 1 inch per second with your random orbital sander), and keep your patterns random, but evenly distributed across the surface. To avoid patterns developing you can sand in a vertical flow one time, horizontal flow another time, diagonal flow another time, etc. We like to use a pencil and lightly scribble on all parts of a surface that needs to be sanded for each grit, and as you work your way across the surface with your sander these pencil marks will gradually disappear, and this helps ensure that you are sanding the surface evenly, and leaving no part untouched (even if it may look similar). Between each grit we also like to wipe down the surfaces with a dry rag or use an air compressor to blow away excess dust, to limit the amount of dust that would be ground into the surface when you sand the next grit.
Spray With Water to Raise the Grain
Sanding wood removes excess material and also compounds the wood fibers, and slowly closes the pores as you move up the sanding grit progression. Between sanding the final grits it is useful to “raise the grain” of the wood by lightly spraying all sanded surfaces with water. The water will re-raise the wood’s fibers, and allow you to get a finer and smoother finish when sanding the next grit. But in this context it is also useful because it slightly reopens the pores of the wood, allowing more penetration and molecular adhesion by the Rubio MonoCoat finish. It is imperative that water does not pool on any surface, and you are aiming to get even water exposure on all surfaces on which you are raising the grain. So for example, let’s say we are sanding a piece that will ultimately be finished after sanding at 180 grit. After sanding at 120 grit, we will slightly spray the sanded surfaces with clean water (or wipe down with a very damp rag), and then let dry completely before resuming sanding. After the surfaces have completely dried we will then sand at 150 grit, and then repeat the water pop procedure above. After that has dried completely again we will then do the final finish sanding at 180 grit, and then proceed to the next step below.
Remove Dust From Sanded Surfaces
After you have completed the task of meticulously sanding your surfaces, the next step is to remove as much dust as possible before applying your finish. This is fairly straightforward, and begins by wiping away all excess dust with a dry rag (or blowing away with forced air from a pneumatic air compressor). Then you can use something like mineral spirits or denatured alcohol (on a rag or blue shop towels) to wipe down the sanded surfaces, which will help clean off and pick up any remaining dust. We specifically use Rubio Raw Wood Cleaner for this wipe down stage, as it acts like hydrostatically charged mineral spirits (or we use Rubio Exterior Wood Cleaner at this stage for outdoor furniture). Then let the wood completely dry for an hour or two. The ultimate goal is to leave the sanded wood raw and free of any lint, dust, or debris that would otherwise prevent the Rubio MonoCoat finish from getting full and proper molecular adhesion to the wood itself. If you are able to, use something to prop your pieces up to ensure proper air circulation around the surfaces so it dries evenly and quickly.
Mixing and Applying Rubio MonoCoat
Once your wood surfaces are fully sanded, prepped, and cleaned in the steps above, it is ready to apply the finish. When using Rubio MonoCoat, it is important to remember that products like this may have what is called an open or working time, so if you are working with large surfaces, or wish to do things in stages, it is better to mix up smaller batches of Rubio and apply it to certain sections, and then once you are finished with that section you can mix up more and move on to the next section (for example, breaking up a long dining table into two halves on both the top and bottom). We like to apply the finish to the bottom of pieces first (non-show side), and then flip over and apply to the top. This lets the piece rest and dry with supports on the underside (or a non-show side). As with anything else when working with wood, air flow for drying and curing is essential, so we like to let pieces rest slightly elevated off of the work tables, so that air can circulate above and below the piece (which will help prevent warping and limit natural wood movement). Anything that is stable and padded can be used to rest upon to elevate the piece.
How to Calculate and Mix Rubio MonoCoat Oil Plus 2C
Rubio MonoCoat Oil Plus 2C is a two part finish that you can quickly mix together prior to application. Part A is the actual oil, and Part B is the accelerator, which reduces the total cure time. Normally when just using Part A the full cure time is about 27-30 days. When used in conjunction with Part B accelerator this full cure time is reduced to 7 days. The ratio to mix is 3 measures of Part A to 1 measure of Part B (3:1 ratio). Rubio advertises MonoCoat coverage as about 300-500 square feet per liter. To calculate how much you will need, you will need to measure your surfaces carefully, and we liberally round up each time to ensure that we mix up more, rather than less, as some woods like Walnut and Oak tend to soak up more oil. This usually works out to about 2ML per square foot of coverage needed. As an example, a 48×24 coffee table works out to about 16+ square feet (plus side edges), so we would mix up about 40ML total of Rubio MonoCoat to begin with (30ML Part A + 10ML Part B, because of the 3:1 ratio).
Shake the cans of Part A and Part B prior to opening, and then open the cans. Measure and pour at a ratio of 3:1 Part A:Part B into a mixing cup (this can be done using a scale, plastic syringes, measuring spoons, etc.), and then stir together thoroughly. Be sure to close the cans to limit air exposure, and then you can begin the application of the Rubio you just mixed together. It has about a 4 hour open time, but it’s best to work in small batches.
Wipe on Rubio, Then Buff Off Excess
Different things can be used to wipe on the Rubio, such as a clean rag, or blue shop towels, but we prefer just using 3M white pads, which are non-abrasive and do a good job of soaking up excess oil which can be used to rub into the surfaces. Work in sections and apply and rub in the oil to the surface, and if any section looks dry continue to apply more. Some woods such as Walnut and Oak will tend to require more and appear thirsty. Once the Rubio has been wiped onto the surface, let it tack up for about 5 minutes, and then begin to wipe all excess off within 10-15 minutes max (we like to use clean white towels or disposable blue shop towels). Go over the surface a few times with new/fresh towels until nothing significant is being picked up by the towels. Per Rubio’s instructions, you can never wipe too much off, but you can wipe too little off, which will have negative effects of gumming up over time, so be sure to wipe off the wood thoroughly. The rags, towels, and oily materials are combustible and require proper attention, and tips and tricks to disposing of these can be found courtesy of NFPA here.
Rubio MonoCoat Cure Time
Surfaces treated with Rubio MonoCoat Oil Plus 2C can be lightly used or moved after 24-48 hours. After 48 hours the finish will be about 75% cured, and after 7 days total it will be fully cured and more moisture resistant.
For more information on maintaining furniture finished with Rubio MonoCoat, please see our step by step guide How to Maintain Furniture with Rubio MonoCoat.