Thought I'd share a recent Zank Inlay project, walnut inlaid into red oak, partly to reopen the subject of waste-backing removal from Zank projects. As Zank vets will know, there have been several methods put forward over the years for the crucial waste-backing removal step and much discussion of the strengths and weaknesses of each.
Rather than review the popular methods, I thought I'd use this 9" x 15" x 1" deep oval tray to put forward my favorite method. Although most of the well-known techniques are not really feasible for removing waste-backing from the bottom of a tray like this one, the method I used for doing it is very easy and gives the craftsman great hand-control over the removal process. It is so versatile and fast, I use it to remove the waste backing from all of my Zank Inlay projects regardless of the project dimensions or geometry.
Note, to save expensive hardwood I generally buy 1/4" thick pieces of hardwood for the male workpieces and glue these to thin particle board of the same x and y dimensions. These blanks are then used in the Zank procedure in the usual way: The male mirror image of the female engraving is carved and cut out from this stock, then glued up and clamped, clamped, clamped.
For waste-backing removal (dust mask and goggles required, ear protection strongly suggested) I secure the workpiece on a shop table, set a shop fan to blow across the workpiece, and hand-remove the waste-backing with a cheapo Harbor Freight Tools high-speed angle grinder fitted with a 36-grit carborundum wheel. This is an extremely aggressive tool, so you must learn the feel of it--it is very easy to mar the actual workpiece surface unless you pay good attention.
The pros of this method: A standard 4" 36-grit carborundum wheel grinds through particle board and hardwood like a hot knife through butter, and the wheels are cheap and last a very long time (I just changed wheels after a year on my first one). Because the user has precise hand-control over the grinder, he can be aggressive early and careful later as the artwork starts to show through in the removal process. (Note, the usual 0.1" protrusion of the male piece from the workpiece surface--e.g, when the flat depth = 0.1" for the male carving--is very helpful for providing a buffer zone between the waste-backing and the workpiece surface.) This is a very quick way to get a Zank Inlay project ready for rough sanding with a random orbit sander, prior to hand finishing. Because hand-control of the grinder allows variable pressure in the x, y, and z dimensions, the user can vary the rate of attack to spare the especially fine areas of a Zank Inlay, which are sometimes subject to being chipped or yanked out of the engraving by methods which don't provide such adaptable control.
The cons: At first, I used to get covered with sawdust during each of these procedures. After a while a lightbulb came on and so now I do this in front of a strong shop fan (still wearing mask, goggles, ear protection). Later, I clean up the sawdust from off of my shop floor instead from of my arms, legs, head, torso, etc. That's the only real con, IMO: The grinder makes a lot of sawdust. On the other hand, it's fun to make sawdust if you're not always being covered with it, so there's that....
