Regardless of whether you believe climate change is man-made or a natural part of the earth's weather cycle, reducing pollution is always a good idea.
I recently read an article titled, "Recycled Oil is Important for Green Living." Great idea, I thought, but let's not stop there. To be truly friendly to the planet, shouldn't we recycle everything?
When you think about this idea for a moment, you realize that some serious economics of recycling come into play. If you want to consider running an "earth friendly" machine shop (what I call green metalworking), we have to be practical and determine if recycling can be more cost efficient than simply replacing the item.
To get an accurate idea of the economics involved, let's clarify what we mean by the word recycling. Many people think of recycling only as taking a used-up commodity and finding a new use for it - for instance, the recycling of auto tires into rubber asphalt paving materials. But recycling in a machine shop can mean simply reusing an item in a way that lengthens its useful life. Coolant is a perfect example. What's more, your coolant doesn't have to be "green" to be environmentally friendly. You only have to know how to make it work to its optimum potential so as to minimize waste.
With a little arithmetic you can easily compare the benefits of maintaining your coolant to lengthen its useful life vs. the costs of not maintaining your coolant so it has a shortened life. Cost savings of 30 percent or more are not unusual, as we will detail later in this article.
At S.C. Chemical Company, we do more than manufacture quality coolants, cleaners, rust preventives, and specialty chemicals. We educate our customers about the best way to use these products and how to save money in the process. This knowledge has the added benefit of helping our customers reduce pollution.
Where should you begin your green metalworking efforts?
Start with a clean machine sump and add enough water to circulate through the lines and pumps. Slowly add a high quality coolant that lends itself to recycling. Most of the premium coolants on the market fit the bill. At the desired mix ratio of 5-7 percent concentration, allow the coolant to circulate and become thoroughly mixed. Check the mixture with a refractometer and you will probably find a nice clear line somewhere between 3.0 and 7.0 (depending on the type of coolant you are using). This is your starting point for maintaining coolant concentration. If a 5 percent solution of your particular coolant provides a refractometer reading of 4.5, then check the coolant concentration daily. If the concentration is higher than 4.5, add water; if it is lower than 4.5 add coolant concentrate.
Here is our five step approach for lengthening the useful life of your coolant:
Improve your water source. If you have hard water, the minerals in the water will interfere with the proper functioning of the coolant. Perhaps not initially; but, as the coolant ages and the hardness in your coolant solution rises, you will experience lower tool life, faster coolant degradation, and possibly rust concerns. Reverse osmosis (RO) water or deionized (DI) water will greatly extend the life of your coolant because contaminants (hard water salts) are eliminated.
Remove the tramp oil. Removing the tramp oil does a number of things to help you. First, you will continue to have more accurate readings of concentration. Then, the removal of the tramp oil will keep the coolant cleaner and allow it to last longer in the coolant sump. Last, from a ‘green' perspective, recycling that tramp oil will be good for the environment.
There are many different methods of removing tramp oil from your coolant sump. They all seem to work in direct proportion to what they cost. The more expensive oil skimmers do a better job; but that should be expected.
Eliminate metal fines. Metal fines often stay suspended in metalworking fluids. The accumulation of metal fines will start to degrade tool life. The presence of metal fines also will affect the life of your machine. Think of coolant with high metal grit content as a sand blaster slowly wearing out the machine's surface. Keep in mind that the metal fines, chips, and scrap can all be recycled.
Check coolant concentration. When it comes to controlling coolant concentration, a refractometer is the easiest tool to use. It will measure your coolant mixture on a scale that is easily converted to percent concentration. The value here is that you only use the coolant you need. Too much coolant (high concentration) is a waste of money and resources, while too little coolant (low concentration) could lead to rust concerns and lubricity issues. So check your coolant concentration daily for the proper mix. As your coolant ages, you might notice that the once clear line on the refractometer is now fuzzy and difficult to read. This is probably due to tramp oil that has leaked into the coolant and is interfering with good refractometer readings. If you have removed the tramp oil as suggested above, fuzzy readings should not be an issue.
Choose the right coolant. This last step could also be considered the best place to start. You need to choose the best coolant for your operation. Your local coolant salesperson will assist in determining which of the many different types of coolant might be best for the metals you machine. The difference in cost between the best product available and the ‘just OK' product could be as little as $1.00 per gallon.
To choose the right coolant you need to ask yourself a few questions:
* How long will the coolant be in service?
* How many gallons of coolant concentrate will I need to charge my machine?
A 100 gallon coolant sump will require 5 gallons of coolant to charge it. This means that the higher priced, Premium Coolant, will only cost you $5.00 more to use in your machine. This doesn't seem like a lot of money when you consider that our objective is to lengthen the useful life of your coolant and help save the environment. Experience tells us that the premium product is most often the better buy.
I'd like to lengthen the useful life of my Shop Talk magazine article from May 2006 entitled, "Five Steps to Improve Coolant Performance," by recycling the conclusion here.
"Using the recommendations outlined above, you could very easily save 25 percent to 30 percent on your total coolant usage. The best way to get started is to ask your current ‘full service' supplier to help you out. If you can't get the answers you are looking for, find a coolant supplier you trust and I'm sure you will improve your total process."
Green metalworking has its benefits. Besides saving the environment, you can improve your processes and $ave another kind of green.
This article originally appeared in Shop Talk magazine in November of 2008. Shop Talk is published by Magellan Publishing.
