I know now that gasoline isn't the only thing that is increasing in price.
It seems that everything related to manufacturing is suffering from the "trickle down" effect of rising gas prices. Tools, steel, or any metal for that matter, transportation, and of course, coolants, are all seeing price increases. And higher gas prices are particularly hard on working people and small businesses.
That's why I wasn't surprised when a customer recently asked me, "Should we consider switching to a synthetic coolant because of the high cost of oil?"
Switching to a non-petroleum-based coolant sounds like an ideal solution and an easy fix, but as with many things in life, it just isn't that simple. I'll explain more about why later on. For now, I'll try to answer the real (bottom line) question, which is, "Given the rising cost of coolant, how can we save money?"
The shortest distance between you and savings is a straight line that runs right through your plant processes. Improve those processes and you will experience less downtime and produce a better finish on parts, which will result in an overall cost savings.
Starting with your present operation, consider making the following improvements on what you are already doing.
(1) "Is there tramp oil floating on my coolant?" If the answer is, "Yes"; then you can save money simply by removing the tramp oil. Here's how it works: Tramp oil leaks from hydraulics and ways, and oil comes in on parts. This oil floats to the surface of your coolant either in areas of the tank that are stagnant or when the coolant is turned off. The tramp oil prevents the coolant from 'breathing' or getting oxygen during circulation. When the coolant lacks oxygen, certain types of bacteria form and breed that cause the coolant to break down. As the coolant breaks down, the bacteria by-product gives off a terrible odor. Now, your coolant is breaking down and it stinks. Your first response might be to dump the coolant no matter what the cost, just to get rid of the smell. But this is a costly and unnecessary response. To keep your coolant from breaking down (and stinking), plan ahead. Install oil skimmers on each machine or obtain a skimmer-on-wheels that can service numerous machines. With the tramp oil removed from your sumps, you'll save plenty of money on coolant.
(2) Now ask yourself, "Am I using hard water to mix my coolant?" If your answer is "Yes", you might want to rethink how you mix your coolant. You may be wondering why this makes a difference. Consider the facts: Calcium and Magnesium are present in hard water. These minerals accumulate in your coolant mixture over time because as you add water to your coolant, you are also adding these minerals. When the water evaporates, the minerals stay behind. So it's easy to see how even moderately hard water can cause a problem given enough time. The minerals can interfere with rust protection because the particles are impurities that will "plate-out" on metal surfaces and act as "seeds" for rust to start. Another concern with accumulating minerals is the coolant can either totally split, or form a creamy layer on the surface. This layer is actually coolant partially split out of the solution. Either way, you are not getting the full lubrication benefit from your coolant if hardness goes unchecked.
Now, the good news - treated water can solve these problems.
De-ionized (DI) water and Reverse Osmosis (RO) water remove the impurities from your water and allow you to mix your coolant with, in most cases, extremely purified water. Water that is treated will provide consistent coolant for your machining operation. It also will help your coolant last longer and work better. And the best part is that treated water will actually save you about 20-25 percent on your total coolant usage. Now, you are saving some money.
To prove point No. 2, let me suggest a simple experiment: take two clear plastic bottles, fill one about 3/4 full of the water you are presently using to mix your coolant, fill the second bottle about 3/4 full of distilled water purchased at the grocery store; then, add equal amounts of coolant concentrate to each of the two bottles. Once you have mixed the coolant, hold the bottles up to a bright light (or direct sunlight) and see which of two provides a clearer solution. My guess is that the coolant mixed with the distilled water will be noticeably clearer.
If you did the experiment and are convinced that better water is the answer, you might be interested to know that by treating your water there are even more savings to be realized. Since you are using less coolant, your waste disposal will cost less. Your rust protection will improve. Your machines will stay cleaner and, believe it or not, they will last longer. The hard water minerals work like sand blasting to etch the inside of your machine surfaces and prematurely wear out side-walls and tables. This is something you can't put a price on; but I'm sure if you could, the savings would be significant.
(3) The last and the easiest suggestion for saving money on coolant is to check your coolant concentration. One of the biggest ways to waste money is to run coolant too rich. Sometimes coolant concentration is increased to provide better lubrication on a difficult metal. This is a good idea, but there is a point of diminishing returns - where the increased coolant concentration does little to improve finish or tool life. If you learn what the optimal concentration is, you will save money simply by running your coolant at the correct mixture.
Please keep in mind that machining with coolant that is too low in concentration is equally bad because rust protection may be at risk.
So at the beginning of this article the question was posed:
"Should we consider switching to a synthetic coolant because of the high cost of oil?"
You'll recall I suggested that the answer to this wasn't simple. This is because the different classes of coolants (water soluble oils, semi-synthetics, and synthetics) each have their own unique features and benefits. Within each class there are a variety of coolant products engineered to be ideally suited for a particular machining application. Saving on coolant cost, but losing on machine performance and plant output is penny-wise and pound-foolish and could easily cost you more than it saves. So, before you make a switch, cool it! First, carefully review the characteristics of the coolants you are considering. Make sure they will give you optimal performance for your metalworking applications.
Please don't change from an oil-containing coolant to a synthetic coolant just because of the price of oil. The three simple money-saving suggestions I outlined above will save you much more than what you're paying because of increased oil prices.
This article originally appeared in Shop Talk magazine in August of 2008. Shop Talk is published by Magellan Publishing.
