Could it be solid surface nirvana? If not, it certainly ranks on just about every fabricator's short list of hoped-for developments in materials processing technology. What we are talking about is a cost-effective and foolproof approach to producing immaculately finished solid surface countertops in a fraction of the time it now requires. In short, the ability to sand a top in minutes rather than hours.
While no one has yet to load that coveted silver bullet into the chamber, there are those within the industry who are vigorously bending mind and will toward achieving the goal of the perfect sanding system.
Just look at the advancements in tool technology. Large format production sanders from Sur-Care, Gem and The Pinske Edge reduce the time it takes to sand a countertop, while ratcheting up overall quality. Exquisitely engineered hand machines, such as those produced by Festool, Fein, Bosch, Dynabrade and others, offer advanced features that offer total control over arc of rotation, the option to choose between radial or random orbit action in the same tool and dust extraction nearing 100 percent efficiency. Specialized sanders are also now available from quality producers for just about every other facet of solid surface fabrication.
Important as these tools are, they all exist to perform the basic function of applying abrasive to solid surface in such a way as to produce a uniform and consistent finish in the shortest time possible. All rely on the latest abrasives technology to convert dusty slabs of raw material into gleaming works of art.
We all know the only way to obtain satisfactory results when sanding is to proceed from coarse to fine grades of abrasive. Knowing how long to sand with each grit and how many grit sizes can be skipped without sacrificing quality require a better understanding of the sanding process.
Each grade of abrasive leaves behind its own signature in the material by creating a distinctive scratch pattern as it moves across the surface. The character of the scratch and its relative depth are determined by the size of the abrasive grain, pressure and speed of movement -- factors which are influenced by the type of machine used, the pad on the machine and operator technique. With each application of successively finer grades of abrasive, the deeper scratches left by coarser grits are erased and replaced by finer, less obvious scratches. As the operator progresses through the grades from coarse to fine the scratches become less noticeable, until the desired finish is ultimately achieved.
Using a very fine abrasive grit to erase the deep scratches of a coarse grit is like trying to load a dump truck with dirt using a hand shovel. It is time consuming and largely ineffective. A better tool would be a front end loader. In the case of abrasives, a slightly less coarse grit would better serve the function of the front end loader than a super fine grit, wiping out the deep scratch quickly, while leaving behind its own, less obvious signature.
"The rule of thumb is to skip no more than two abrasive grades when sanding," explains Jerry Horn of SIA (Swiss Industrial Abrasives). "Anything more than that and the finer grits can't get rid of the deep scratches. That is also why it is important to make sure you have eliminated the deepest scratches before moving to the next grit level. If you don't, you most likely won't ever be able to get them out, and it will show up in the final finish."
Complicating the issue are sanding products that might contain various sizes of abrasive grains within the same grit level. Thus, while you may be effective in removing deep scratches with a slightly finer abrasive, one oversized particle (wild grain) stuck to the pad can leave behind its own signature gash that the next level of abrasive will be hard pressed to remove. Put enough of these random scratches in the surface as you go through the sanding steps, and your top will radiate a blotchy or hazy appearance.