By David P. Monyhan (retired),
As seen in Engine Builder Magazine
Over the past several columns, I’ve talked about a variety of shop machines and their maintenance schedules. I’ve talked about how to get your shops cleaned up and looking good for customers’ inspection. This article is going to deal with a problem that’s right under your nose … coolant aromas.
Let me paint you a picture of summer in your shop … the birds are chirping, the fish (and mosquitoes) are biting and everyone is enjoying the steamy days of summer. It’s late in the day, when you walk into your shop and suddenly you’re stopped dead in your tracks! There is a looming malodorous emanation in the air. “What is that smell? Where is it coming from? Do my customers smell it too?” I mean the smell is so bad, that even stink would say “Whew that stinks!”
Guess what? It’s the coolant tanks in your shop. That’s right, all that grinding swarf and metal mixed together and fermenting in your coolant reservoirs have promoted the growth of bacteria and fungi which are now contaminating your coolant systems.
How could this happen, you wonder? Let me give you a little background.
In the days of old, we used heavy petroleum based coolants. It was nearly impossible to maintain proper mix levels and coolant life was never very long. Today, we use mostly synthetic coolants, which are better in a variety of ways. They last longer, keep the work piece cooler, prevent rust in the machine and prevent the abrasive wheels from loading up. They’re also easier on your dial indicators and other tools that come in contact with the coolants.
But how do the microorganisms get into the coolant system? They’re not in the coolants themselves, right? It all comes down to one simple ingredient. Water.
That’s right, water. Some water is hard, and some is soft. Despite all of the treatments and purification systems, some water still contains microorganisms, and of course, the heat of summer can cause nasty things to happen.
Well, what are you going do about it you ask? I’ll tell ya what we’re going to do. We’re going to have to clean the coolant systems. All machines that use coolant in their machining process are subject to this bug growth. Surface grinders, flywheel grinders, belt grinders, crank grinders, cam grinders and other water-cooled machines fall into this category.
A quick and dirty solution is to cover up the smell … a little Pine-Sol™ in the tank, a little more coolant … but that’s just a band-aid approach and won’t get to the root of the problem. Here’s what I suggest to combat what’s bugging you.
Take a look at your schedule. Is there a stretch when you won’t be using your machines? The weekend, or perhaps some vacation days coming up? Take advantage of that down time to clear the air.
The day before that down time begins, drain out all of the coolant from all the machines. It’s important to clean all of your machines at the same time so that you won’t risk cross-contamination from one machine to another. Remove the coolant pump and clean the entire reservoir with a diluted solution of bleach and water. Remove the intake screen from the pump and clean it as well as the impeller. Next wipe down all the coolant return troughs. Now is the time to remove all the coolant hoses. This is where people get re-bugged. They forget or don’t know to remove the coolant lines. They need to be flushed or even replaced.
Coolant lines and troughs are great places for bugs to set up house keeping. These components develop cracks, fittings and connections have crevasses where they interface; unpainted castings have porous surfaces. All these areas are “critter condos,” complete with rest rooms. What you smell is their untidy style of living.
Wipe them thoroughly with the bleach solution and dry everything completely. Now its time to repaint the troughs to seal the surface.
Once everything is cleaned and painted, take that time off. Spend time with the family. Have fun! When you return to work, get there early and reassemble your machines. Add fresh water to the coolant tanks. Mix the proper ratios of coolant per manufacturer’s recommendations. Now the final step. Add some Microbiostat to your coolant tank. This additive will prevent that bacteria and fungi from reforming. As always its important to periodically check the levels of coolant to water ratio. Get a good PH checker. This test will also tell you when you need to add more biocide to your solution.
Why is all this treatment necessary? Because, unchecked growth of microorganisms in metal working fluids can cause fluid break-down, resulting in damage to the coolant systems and components, tools or even the work piece. Microorganisms can also affect workers by causing foul orders, skin irritations or even worse, allergic reactions, which can cause an employee to miss work.
Keep a written record of when coolants are changed as well as when additional biocide is added. This will keep you a step ahead of those bugs trying to infiltrate your systems and most importantly the workflow. Clean fresh coolant will always deliver a better finish on the various work pieces you machine, and it keeps your machines from rusting as well. So drink up, enjoy a cool refreshing glass of water, and watch out for bugs in your shop.
Don’t forget, if you have more questions, contact the Goodson Tech Department at 1-800-533-8010 or visit the Tech Bulletin Board.