First of all, never run a diamond blade dry as this will destroy your blade fairly quickly. That being said, we recommend you only use a high-performance low viscosity commercial-grade mineral oil without added petroleum distillates or solvents. Your coolant should be kept clean either by filtering it or using our EverClean system and the external operating temperature should be kept between 60º F and below 100º F. Sludge from cutting should be removed regularly and replaced with fresh coolant.
Run these coolants to protect your warranty and optimize the performance of your saw:
- Highland Park Lapidary Cool Cut (or equivalent 5-7 CST viscosity mineral oil with no added petroleum distillates or solvents)
- Shell Diala AX
- Chevron Texaco Bright-Cut
Do NOT run these coolants as they will damage your saw and void your warranty:
- Automotive Antifreeze Coolant
- Automatic Transmission Fluid
- CNC Machining Fluids (except Bright-Cut)
- Diesel, Heating Oil and Kerosene
- Used transformer oils
- Engine Oil
- Hydraulic oil (new or used)
- Concrete form oil
- Vegetable oil
- Food Grade Mineral Oil (such as Tractor Supply Corporation mineral oil for large animals as this is far too high of viscosity and performance varies greatly based upon temperature fluctuation)
- Mineral oils with added petroleum distillates or solvents as this will strip lubrication from internal roller bearings and bushings
An important story about coolants:
The type of coolants you use to run your equipment is critically important to cutting performance. We were reminded of this recently when one of our customers in Madagascar was drilling rose quartz using our core drill they had purchased a mineral oil that had a higher viscosity that is very similar to the food-grade oil that a large majority of our customers are attempting to use. In this particular case, they were using a 6-inch diameter bit attempting to drill 6 inch long cores in rose quartz. They had drilled for about 40 mins and only gone 1/2 inch deep. We looked at all the mechanical issues, diamond core bit, and the overall functionality of the core drill and everything looked just fine and exactly the same as what we run our China and Philippine cutting facilities. The only difference was the type of coolant being used. We shipped over 5 drums of coolant that we use which is a low viscosity, high flash point, commercial mineral oil used in cosmetics which has a viscosity close to that of water. Simply by changing out the coolant, the same drill with the same bit was able to drill 6-inch diameter 6 inch long cores in rose quartz in less than 8 mins. All this was accomplished by simply changing the coolant.
We sometimes get calls from people saying their saw is not cutting properly or not cutting at all. Usually, these calls start happening in September. Our first question is always “what coolant are you using”. If you are cutting hard materials like Mookaite, petrified wood, or other hard agates and jaspers, water-based coolants will simply not work. Your blade will immediately become dull and the blade pressure will increase with little to no results.
Likewise, if you run a high viscosity mineral oil like the TSC mineral oil for livestock or other food-grade mineral oil (which we are not fans of) your saw will cut poorly. The reason being is that the viscosity of the oil is too thick and the oil and sludge build-up and can't get out of the way of the blade so blade pressure goes way up but the cutting is poor because the pressure on the diamonds against the rock is low. It is basically is like hydroplaning of car tires on a road. The thick oil and sludge act like a shield between your blade and the rock resulting in high blade pressures and low cutting performance.
Some old-timers will argue that coolants like diesel, kerosene, or fuel oil with a little bit of oil are fine. Not so. These are all solvents and as such will strip the lubricant out of the bearings and will void your saw warranty. Furthermore, they do not provide enough lubricity to the blade (like water) and your blade will quickly become dull and stop cutting. And let's not forget fires - diesel, kerosene, and fuel oil have LOW flash points - meaning they catch fire at relatively low temperatures. This is why they are used as fuels. There have been at least 4 shop fires resulting in the loss of all gear due to folks running these solutions.
We had a customer running one of our 36-inch saws who was running this diesel/kerosene/fuel oil combination. He was having all kinds of problems cutting even 6-inch diameter pieces of petrified wood. Believing the grandfather myths of running this combination, he of course blamed all the problems on the saw, not his blade or the coolant. He literally burned up one motor which we replaced at no charge. When the problem persisted, we flew out to see him and determined that there was nothing wrong with his saw (though his roller bearings were pretty wiped out by the solvent nature of his coolant) but instead his problem was caused by the coolant he was running and an extremely dull MK Diamond blade. We sharpened the blade and the saw cut fine but we warned him that without changing his coolant and keeping his blade sharp - or getting a better cutting blade like the GreenLine Agate eater, the problems will continue to reoccur.
Now that our Highland Park Cool Cut oil is available and has the lowest cost of any coolant on the market with free shipping in all the lower 48 states, there is no reason to use lesser grade coolants that will make your saw perform poorly. Coolant is one of the most important factors in slab and drop saw performance.