Lapidary Equipment | CRATEX Abrasives

Lapidary work involves using a series of grinding wheels and belt sanders usually with water cycling in the system. The most important thing for a beginner lapidarist is to get a start-up equipment that will enable some sort of progression of the grits and to get a handle on the graduated stages that involve grinding, sanding and polishing.

The choice of equipment is usually limited due to the knowledge and the cost. In case you are just starting, you’ll at least need a trim saw and a cabbing machine. With Diamond Pacific Genie with 6 wheels and a separate machine for cutting slabs, you’ll get yourself a more than a decent setup.

You can buy additional arbor type set-ups only for convenience, as it will enable faster and easier transition between the greater variety of abrasive wheels and papers. But, if you’re not ready and able to invest more money in additional arbors, you’ll still get the work done, you’ll just need to spend more time removing and replacing various grits and wheels that came with your combo unit.

But, first thing’s first. For all you newbies, we’ve decided to write a guide through different tools and equipment used in lapidary work.

 

#1 Lapidary Slab Saw

The size of the slab saw blades ranges from 6-36″ (typically 16-24″) in diameter with thickness of .025” to .200”. They are designed for heavier cutting, used to cut rough rocks of several inches thickness into thin slabs (usually 1/8-3/8″).

Thicker blades can give you a nice manicure if you are not careful, so pay attention to your safety when cutting stones with a slab saw. Also, make sure that the stones are fed straight into the blade when operating a slab saw, because if fed at an angle, the blade might bend which can damage it. You don’t have to pay as much as attention to this when operating a new slab saw but be very careful if using a used one.

Most of slab blades are diamond blades, but old-school mud saws are still on the market. Mud saws don’t have abrasives on the blade, but the blade runs through an abrasive groove (usually silicon carbide) or “mud”. The mud saw is much cheaper than the diamond blade saw, but it requires more maintenance, as the abrasive wears off with use. However, with proper use and maintenance, a mud saw can be a perfect, yet cheap tool for rough stone cutting.

 

#2 Lapidary Trim Saw

Trim saws are typically 6-10″ in diameter with thickness between .004” and .012”. The thin blades are designed to remove just a small amount of material and are used to trim basic shapes from slabs. They are used to either cut smaller stones into thin slabs or to cut small sections out of them.

Very thin blades of .004” to .006” bend more easily and they can be extremely dangerous, so watch out for your fingers as you could lose them. Unless you’re working with material that is very expensive, it is recommended to use thicker blades. You don’t have to use any additional lubrication with these saws, water is sufficient. However, in case you want, you can add a liquid for preventing rust which also has lubricating properties.

The stone is fed to a trim saw by hand. Here too you'll need to be careful to feed the stone straight, as it will bend otherwise. Since no manufacturer recommended that you should feed the stone to the blade by actually holding it in your hand, you might want to think of a way to do it differently.

For example, you can press a small stone on a piece cardboard and then slide the cardboard towards the blade. However, in some cases the cardboard-way can get difficult, so you’ll need to use your hands after all. The trick is to mark the stone for cutting and to keep your eye in line with the blade, use gentle movements and look out for bending.

Slab and trim diamond blades vary in size and in price. The price depends on the amount of the diamonds bonded. In case you are a hobbyist, any good quality blades with rolled or bonded diamond abrasives will do. A better choice for a professional who uses the tools frequently is a sintered blade with a rim with diamonds throughout it, not just on the surface.

More diamonds mean higher price, but also a longer-lasting tool. Professional or not, just stay away from blades that are extremely inexpensive. You might be thrilled to come across a blade that is considerably cheaper than other blades on the market, but keep in mind that there is a reason for every price. Cheap blades will cut a few stones and you’ll be done, so it’s not worth your money nor your time.

 

#3 Cabbing Machine

Cabbing machine holds several wheels of progressive series of diamond or silicon carbide grits that are turned by a common arbor and a motor, and a water supply to wash away the debris or to prevent overheating of the stone.

There are a lot of options and there is a serious difference in the price. Choose a machine based on your needs and the type of work that you do, and always think practical.

In case you do this for a living and not occasionally, it’s best to look for machines with a lot of wheels and a separate machine for cutting slabs. Less wheels mean that you’ll need to change the pads and wheels a lot which is tiresome and a waste of precious time. In case you have a machine with 6 wheels, for example, you’ll easily move from a rough to soft wheel.

 

#4 Lapidary Grinding Wheel

Lapidary grinding wheels are usually metal wheels with abrasive particles (usually diamonds) bonded on their surface, or they are entirely made of an abrasive material, such as silicon carbide.

Metal wheels are more expensive, but they last longer, while abrasive wheels are less expensive and wear slowly, so you’ll need to occasionally dress them with a dressing stick. Wheels are oriented vertically in a lapidary machine and the stone is ground against the wheel's circumference.

Most units come with one or more sanding drums or rubber wheels that hold sanding belts, while a lot of units have polishing attachments like flat discs or polishing wheels as well.

 

#5 Lapidary Flat Lap

These can be either rotary or vibrating and are used to grind or to polish slabs or other flat surfaces, such as some types of cabs, crystals and geodes.

Vibrating laps are similar to tumblers, because they use polishing powders or silicon carbide grit in the same way the tumblers do. Place the slab face down on the lap, add the grit and little water, sit back and enjoy the view. In some case you can use weights to secure the contact between the work piece and the lap, which will speed up the process.

Rotary flat laps, on the other hand, are machines with a rotating abrasive disc. The abrasive disk is oriented horizontally or vertically in a lapidary machine and the stone is ground against the flat side of the disk.

 

#6 Lapidary Polishing Wheel/Lap

Lapidary polishing wheels, belts, laps and pads are used to smooth out small uneven surfaces of your stone and to bring it to a perfect shine.

There are a lot of different types of pre-polishing and polishing wheels on the market, made of different materials and different grits. Depending on your work, you’ll probably use more polishing tools for achieving the desired look on a stone.

Most commonly used lapidary polishing tools are rubber belts, leather wheels and rubber bonded silicon carbide wheels of different grits. Depending on the polishing tool and the workpiece, you’ll also use some lapidary polish.

 

#7 Lapidary Combination Machine/Unit

Combination machines are any combination of lapidary devices in one unit (e.g. a trim saw with grinding and polishing wheels). Highlander Park offers nice combo units with different grit diamond sintered wheels and the option to attach flat metal disc with felt padding and a leather pad and to mount rubber padded discs when needed.

Another manufacturer of lapidary equipment and various combo units is Covington Engineering from Redlands, California.