We don’t see hand rubbed finishes very much nowadays. The trend has been to use a flattening agent to reduce the sheen. While these additives do effectively reduce the sheen, they also cloud the finish. In fact, most finish manufacturers recommend using a flattening agent only on the final coat since adding it to intermediate coats will further cloud the finish. Excessive use can also compromise the integrity of a finish. Using a flattening agent as opposed to hand rubbing has several advantages for the woodwork manufacturer. First of all, it’s easy to use. Just add the right amount of flattening agent to the final coat to obtain the desired level of sheen, spray it on, let it dry and ship it.
Secondly, since it makes the finish cloudy, a flattening agent can help obscure defects that exist below the surface. Shortcomings in grain matching, surface preparation and coloration are less obvious because the hazy surface of the finish obstructs the view of what lies below.
When finishing material comes off the gun and it settles on the surface of the wood, it doesn’t level completely. Surface defects such as orange peel, overspray, contaminants, runs, etc., can be minimized but not completely eliminated. High-gloss coatings produce a harsh shine that magnifies these irregularities. Bringing down the level of sheen with a flattening agent doesn’t eliminate these defects but mutes them by causing reflected light to be scattered.
The problem is that as we obscure defects, we also obscure the characteristics of the wood. Taken to the extreme, it becomes hard to distinguish between real wood and artificial wood substitutes, such as printed wood grain. In fact, this is an advantage to a manufacturer who wants to substitute a molded plastic part for carved wood part. If cheaper is what we’re after, this is the right way to go.
On the other hand, some segments of the market are willing to pay for the skilled labor necessary to produce a hand rubbed finish. They’re willing because they appreciate how a hand rubbed finish looks as compared to an off-the-gun finish. Of course, hand rubbing is only the final touch in the finishing process. All steps in the process must work together to show the attributes of the wood to their fullest potential.
Hand rubbing works to level out irregularities on the surface of the finish by abrasion. Most procedures start by using fine sandpaper to level the surface. Then, “softer” abrasives such as steel wool, abrasive pads and rubbing compounds are used to control the final level of sheen. Both of these steps are broken down into sub-steps that use progressively finer grits to remove scratches left by the previous step. The finer the grit you use for the final step, the higher the sheen.
The process of hand rubbing can vary substantially in method and scope. The simplest method is to first rub the surface with a single abrasive such as 0000 steel wool. Then apply a wax or other polish to “re-wet” the surface. At the other end of the spectrum is the high gloss mirror finish. It requires sanding the finish completely level and then using finer and finer abrasives to eliminate all but the finest scratches.
Regardless of the scope of the rubbing process, the results will far out-shine the use of flattening agents. The process of leveling imperfections improves the clarity by reducing the amount of scattered light that’s reflected. The surface will feel better to the touch, as well, since overspray and contaminant-based defects will be smoothed out, if not eliminated entirely.
The amount of rubbing necessary will be determined by customer preference and the constraints of cost. The best approach is to show customers samples of finishes that illustrate the results of several hand rubbing processes that you’re willing and able to accomplish. Calculate comparative costs for each job since the amount of labor varies depending on the intricacies of the particular job.
Hand rubbing is the final step in producing a fine finish that will show your work to its best potential. It shows the quality of your work in a way that doesn’t have to be explained. The only drawback is the work needs to be seen first-hand to be fully appreciated. Pictures, especially over the internet, can only simulate the actual beauty of a hand rubbed finish.