Using a Rociprolap to Grind and Polish Glass

Using a Rociprolap to Grind and Polish Glass


While a Rociprolap is a very straightforward, simple grinding machine to use, there are some important parts to consider when setting up the Rociprolap once you un-pack it. The first and most important step is to remove the white packing grease from the raceway on the bottom of the grinding pan and the shaft that the pan rests on. This grease is to protect the raceway during shipping and is not there to lubricate the pan. It MUST be removed before using the Rociprolap. Once the pan is off the base, you need to insert the small round steel plates in the bearing keepers and then two nylon balls in each bearing keeper pocket. Cover the plate with a 30W or 40W motor oil and the nylon balls will then lubricate the pan as it moves. Check the oil level after the first week of use to make sure the nylon balls are still being lubricated.


The great thing about a Rociprolap is it requires very little attention and very little grinding media. Since the grit is recycled in the pan, you can use a small amount of inexpensive loose grit silicon carbide to accomplish your grinding. Put your piece in and let it go! Now you have time to work on other projects while the Rociprolap does all your grinding.


If you're studio space or budget only allows for a single Rociprolap, you'll have to take the time to thoroughly clean your pan between each grit. This can be a lengthy process to make sure you do not cross contaminate your grit from the rough step to the fine step. It can be much faster and easier to have a different Rociprolap for each grinding step; a rough grind, a fine grind, and a polishing stage. You can even have a single Rociprolap with multiple pans and simply change pans when you move to a new step.


Rociprolaps do an excellent job of grinding pieces very flat. This can become an issue when you move into finer and finer grits as the glass will have closer contact with the Rociprolap pan. This can lead to the creation of glass joints, where two very flat surfaces seal together and create a joint by shear surface tension. It's a fascinating occurrence, but the science will be lost on you when you find you cannot remove your piece from the Rociprolap pan. Compressed air blown under the glass through a Rociprolap pan divit will often separate the piece from the pan.


Finishing a piece in a Rociprolap really gives you a new appreciation for how great a grinding tools this really is. Polished surfaces retain crisp edges and bright beautiful polishes with very little interaction or cerium. Since the cerium is continually recycled, the Rociprolap cuts down on cerium usage and the lengthy, tiring, back breaking chore of accomplishing a polish on your pieces.