These full color sandstone parts, or blanks, are intended to be used with standard commercially available 7mm ornament kits. The blanks are designed with built in narrow gaps between colors to allow the color patterns to extend close to the central core hole. Due to the nature of the printing process color pigments are only included within about 1mm of the colored surface, so after machining non-pigmented white zones may appear depending on the pattern geometries. There is always the possibility that changes in 3D printers used, operator settings, calibrations, etc. can alter the internal color patterns over time so this is more of an experimental project to try for the fun and uniqueness of the end product.
Words of warning: Using sandstone material with ornament kits can result in cracked ornaments. Cracking can occur during the step when the hardware end pieces are pressed into the brass tube passing through the center of the ornament. Some ways to reduce the chances of cracking are 1) to use a flexible adhesive between the brass tube and the ornament body and 2) to not compress the ornament body during the press fit operation. Careful assembly and leaving small gaps between the ornament body and the assembled hardware can help to reduce the chance of cracking or breakage.
Background information and kit examples:
Example instructional videos:
Some example kits:
Note that these blanks are sized for the Woodcraft and Woodturners Catalog (Craft Supplies USA) kits which require an approximately 1.4 inch long blank. The Penn State Industries kits contain longer brass tubes which means you would need to trim the tubes or add additional materials to fill the empty space. With care the ends of the blanks can be sanded flush with the internal brass tubes after they are glued in place. I prefer to use a sheet of sandpaper laying on a flat surface and sand each end by hand making sure to keep even pressure on the sanding surface to keep the sanded surface as flat as possible and perpendicular to the central axis of the brass tube.
Full color sandstone is similar to hardened wallboard and is therefore very soft compared to woods or plastics, but it also machines very easily on a lathe or with a Dremel-type tool. Since it is soft it is also a bad idea to clamp the material in a vice or to strike the surface on a hard corner. The machining process can result in a surface that is very smooth but sanding with high grit sandpapers and polishing pads can improve the surface smoothness. A final light coating with a clear spray lacquer before attaching the finials provides a nice protective finish.