Choosing and Using a Flat Lap

Covington manufactures a wide variety of flat laps suitable for working either glass or stone. Ranging from small, table-top models, to large floor models, we have a unit to suit every need. Consider these questions before purchasing a unit: How big are the pieces I’ll be working? How much room do I have in my shop? What type of material will I be working on this unit? Once you have answered these questions you can begin to shop for the right machine to suit your needs.

Maxi Laps

Covington’s Maxi Lap units come in a variety of styles to suit the needs of both glass and stone workers. These units are available in 8” and 10” sizes and feature a full lap face for grinding. This unit is small and a great choice for a table-top or workbench. The unit fits neatly into an 18” x 24” area. The motor mounts directly to the back of the unit and a simple pump and bucket system can provide water to the grinding area. The aluminum grinding heads screw onto and off of the arbor shaft. 

TOTALLY HIP Tip: Spraying WD-40 on the threads prior to screwing the head on ensures easy removal after use. There are eight different systems available which ensures a fit for most small lapping needs.

Beveler & Grinders

Covington’s Beveler & Grinder Units are professional grade machines designed to grind and polish glass and stones quickly and cleanly. These units feature a Blanchard Ground, mild steel plate to accept magnetic backed diamond discs. These units are available in 12”, 18”, and 24” sizes, with single speed and variable speed options.


Why should I spend more on a variable speed when I could buy a single speed for far less money? There are many advantages to the variable speed unit, not the least of which is the ability to slow down the plate speed for polishing which minimizes polish waste. The plate is reversable which allows the user to spin the plate in either direction based on preference. Many consumers also believe that by having a bi-directional plate, you can get a longer life on your diamond discs because you can hit the diamonds from both directions.


My house won’t accept three-phase so I can’t use your machine. This is a common misconception. The variable speed units are marketed as three-phase but you do not need three-phase power in your house to work the machine. The controller we use converts the three phase motor which gives the unit constant torque and horsepower at all speeds. These units can still be used on standard household current. Variable speed units can now be used on GFCI outlets without tripping a breaker.


Covington Maxi Laps and Beveler/Grinder Units utilize diamond discs for the most efficient grind and polish. The Diamond Maxi Laps come complete with your first set of diamond discs required for grinding and the additional discs needed for polishing. The Beveler/Grinders do not come with a set of discs as there are a variety of options available and different types of work pieces might require additional steps.

We can confidently recommend a four step disc system for people who wish to grind and coldwork polish glass. The Covington standard four disc grinding system includes one 100g diamond disc, one 270g diamond disc, one 325g resin bond diamond disc, and one synthetic felt polishing pad. You will also need cerium oxide, if you will be polishing glass. It is important to remember that discs are consumables and must be purchased in addition to the unit. We are happy to provide a complete quotation and make recommendations on discs upon request.

The Beveler/Grinder units accept a variety of accessories such as diamond cones and domes. These items are great for grinding and shaping inside curves. People particularly like them for working the inside edge of glass bottles. The accessories do not come with the male-to-male brass adapter needed to attach them to the plate’s center.

Water Hook Up

Covington’s Flat Lap units accept 1/4” plastic tubing for their water hook up. We usually recommend using a submersible pump and bucket system for fresh water supply to the unit. We also recommend having the dirty water drain into a second bucket separate from the fresh water input; this eliminates the chance of cross-contamination from the used water. Covington’s water pump is an inexpensive choice for connecting water to the unit. This pump features a quick press-to-connect brass adapter to connect the 1/4” tubing to the pump. The Maxi Laps and the Beveler/Grinders also feature a press-to-connect on their water manifold making water hook up very simple. The pump is submersible which means you simply place it into a bucket of water to begin pumping.

The only units that do not accept this type of water system are the 16” Single Speed and Two Speed Flat Laps. These units come with a small cannister to hold water and slowly drip the water onto the plate. Having a constant flow of water from a pump would wash all of the loose grit and slurry off of the plate eliminating the ability to grind.