Hydraulic oil science. Base oils & Additives

Neil from Messick's here out in our parts warehouse today to discuss hydraulic fluids with you today. Specifically a couple of the properties of hydraulic fluids, the additives that go into them. You follow me down this aisle here, you're going to see there is a long, long list of colorful buckets down here. We have all these colorful buckets because there could be wild variety in what is actually contained in them.
There is very few standards out there for hydraulic fluids, and I think that's something really important to understand. Oh, so often I hear people giving advice saying, "Hey, use whatever hydraulic fluid fits the standard." As you're going to see here today, standards and hydraulic fluid don't really go hand in hand.
Starting with the cut-and-dry portions of this complicated conversation is where are their standards? We're all very used to looking at engine oil. If I'm going to go pick up engine oil for my tractor, maybe I'm going to need a 15W-40. You're going to notice before that number it says SAE. SAE is the standards body and they define what goes into a bucket of 15W-40. You could rest assured if you're buying a 15W-40 engine oil, it's going to work just fine in your engine regardless of what manufacturer's name is on that bucket. There are some standards there.
There's also some standards here in hydraulic fluids. When we walk up and down these shells, we can find some buckets to say ISO on them, and typically ISO 32, ISO 46, or ISO 64, those are referring to the various viscosities of that hydraulic fluid under the ISO standard. However, that ISO standard for the hydraulic fluid might represent at most 10% of the buckets that are in these aisles.
Beyond a handful of standards that are out there for hydraulic fluids, you get into all the other wide-ranging formulations of hydraulic fluids. That's the result of all of these many colorful buckets that are out here. Now, there's going to be some commonality between all of these oils because there is a base oil that's shared among a lot of these products. Now, many of you are aware when you drive up and down through the oil fields of Texas, you don't see a giant tractor company logo on top of the oil derrick.
Most of these products come from what's called a tool blender. There's only a handful of companies that actually produce these raw hydraulic fluids and they mix them up for these different companies. As I understand, you can get hydraulic fluid formulations in only a couple of thousand gallons at a time. It is possible to come up with some really unique formulations and be able to bring them to market without having to buy hundreds of thousands of gallons. You can find some wild variety of what's actually contained in these buckets.
Now, as we said though, there is a base oil here used by that tool blender that probably is ending up in many of the products that are on these shelves. The most commonly used base oil in hydraulic fluids is mineral oil. Mineral oil is a byproduct of the crude oil refining process. It's a cost-effective oil that's usually found in the less expensive buckets of oil that you're going to buy. Mineral oil has some good properties to it for use in hydraulic fluid. It can withstand high temperatures and has good lubrication properties, but as years have gone by, better products have been developed.
Anytime that you see the word synthetic or semisynthetic on a bucket of hydraulic fluid, you're moving into now a different category of base fluid. Semisynthetic or synthetic hydraulic fluids are going to improve on some of those base properties of that mineral oil, mostly in the ways that they're going to be able to have better performance in terms of lubrication, their viscosity may be a little bit more consistent and their temperature withstanding is going to be better at high temperatures, the oil is not going to break down as quickly.
The ingredients list here, when we move into these synthetics and the additives that we're going to talk through here shortly. They read like a box of donuts, it's going to last like 20 years. There's all kinds of very complicated names and formulations that go into these synthetic oil products, but they are going to be the highest performance and unsurprisingly, the highest cost oil.
Our next category of base oils are the biodegradable oils. If you see that word show up on a bucket of oil, you're probably looking at an oil that is derived from rapeseed oil. That's going to use a natural product to go through and extract that oil to come up with an oil that's suitable in a hydraulic system. The main use for that oil is for its biodegradable properties.
If you're going to be working, say in a situation out in a field where you're concerned about oil spillage on the ground and its environmental impact, a biodegradable oil is going to have some benefits. It is the, call it, least performant of these different oils because it is going to break down easily and it doesn't have as high of a temperature resistance as performance is going to be less than the other types of oil.
There are other specialty oils that can use different base oils than the ones that we've covered. The one that we commonly will see through here is usually oil for fire retardant use. These are usually going to use a glycol or silicon base in order to construct that hydraulic fluid. They can be very costly because of the uniqueness of them and the additive packages that go into them. I've seen buckets of oil literally over $500 before, over $100 a gallon for those real specialty applications. Usually, it's in a situation where an oil leak on a machine could result in some kind of fire. They're very unusual but also very costly.
Where oil science really starts getting crazy is when we dive into additives, and this is where we come up with so many names. I'm not even going to try to pronounce them, but you can have as many as 0 to 20% of this bucket of oil being made up of additives. The additives are the most costly part of the formulation of your oil. You could literally take a bucket of base oil and stick it on the shelf somewhere and call it hydraulic fluid. Most of the things that we're really concerned about in terms of your machine and its performance are going to come out of these additives.
The first additive that we're going to be concerned about is anti-wear additives, and most specifically, usually, zinc is going to be the one that you're going to find really commonly. That is going to be put into that in order to bond those metal surfaces and create a protective film over top of the metal surface that can reduce the friction and the wear that's happening as your metal components are moving back and forth.
Our next additive is antioxidants. Now, when I think antioxidants, I'm thinking like walking down the aisle at the grocery store looking for blueberries or something. That's not what's ending up in here, but antioxidants are a additive that can be added to a hydraulic oil. The purpose of them is to keep the oil from reacting with oxygen. When oils are exposed to oxygen, it breaks down the oil over time, it is going to last for a shorter period of time in your hydraulic system, so having antioxidant additives in your hydraulic oil can extend the amount of hours that it can perform in your equipment.
If you store your equipment outside, you're going to want to pay special attention to having corrosion inhibitors in your hydraulic fluid. As temperatures rise and fall, condensation can start to develop on the inside of a piece of equipment. Now, you might not think about this, but there are vents that let air in and out of the inside of a piece of machinery, and water building up in hydraulic fluid over time through those vents or through say, leaks and gaskets and stuff in your equipment, can cause water to work its way in.
Corrosion inhibitors are going to coat those metal surfaces on the inside of those transmission cases and keep that water from rusting up your machine from the inside out. Now, if some water does happen to get in your hydraulic fluid, as those gears are spinning and the shafts are turning and the pump is sloshing that fluid around the inside of the machine, the fluid can start to foam.
Now water exasperates that problem, but any liquid like that can start to get a little bubbly and stuff. If that starts to work its way down into the gears on your machine or even get pulled down into the hydraulic pump, it can cause cavitation. It can cause a lot of premature wear on your hydraulic components. Foam inhibitors are another additive that is in many of these hydraulic fluids.
Just like an engine oil is going to have a viscosity range, say 10W-30, that tells you the thickness of that fluid at different operating temperatures, hydraulic fluids are going to have viscosity ranges as well. Now, these are not clearly published on the side of the bucket in the same way that engine oils are, but you're going to have additives put into that base fluid in order to modify the viscosity, both to thicken it at particular temperatures or to thin it out when it's cold as well. It could be done in both directions. That is done with two different types of additives.
As the machine is operating, you can get that water ingress that we've been talking about, but you have metal and metal surfaces rubbing together as well, and those surfaces are going to wear. You're going to get some of those minerals, those metals rubbing off of those surfaces and floating around in the oils. That's addressed by our next category of additives, that would be detergents and dispersants.
Now, those are there to keep those minerals from building up in particular places in your machine where a slug may come through and do some damage, or in the case of water is to disperse it throughout the oil so that it can continue to run evenly and consistently through your hydraulic system and not, say, accumulate up on a top layer where when pulled into the machine, it could do some damage.
All of that conversation, I think, should really lead to the conclusion that all of these hydraulic fluids are not the same. Anybody that gives the advice to go out and say, run whatever hydraulic fluid meets the spec is ill-informed here at this point. There's huge variety in all of these additive packages in their base oils. One oil is not necessarily like the other. You will notice, however, that when you spin one of these buckets around backwards, particularly the ones that aren't made by a major OEM that's trying to sell their oil to go into their equipment, you'll find a number of different standards and things listed across the back of these buckets and all of the things that they are supposedly compatible with.
What you are reading on that label is the opinion of the manufacturer of that bucket of oil, figuring that product should be okay in the applications that are called out for by those other oils. More than likely, I believe the analysis that's being done there is that they're sharing the same type of base oil, but they're not doing the work to go through and clarify all the different additive packages that might be in all of those different products. It is solely the opinion of that oil manufacturer that that product should be okay and all of that other equipment, it is not guaranteed that it's going to work out perfectly.
Now, if I haven't shown you enough buckets by now, behind me is our bulk oil system. There's over 30,000 gallons of additional oils in these giant drums behind me here, and all of these reels that we can use in order to pump that oil down into smaller containers that we sell over the counter. These five-gallon buckets, many of them were pumped out of this system or for bulk delivery. We have an oil delivery truck that will go out here locally and deliver these different products to you.
As you can see, we believe in the science that's in many of these oils. The guidance that we're usually going to give is that the only company that you can really trust for the oils going into your machine is the company who made that equipment and we do see performance issues when the wrong oils are run in the wrong machine. At the very least, if you're going to deviate off of that manufacturer's bucket of oil because you don't want to pay the percentage of profit that we all know is ultimately in there, at the very least, look for good quality products by going and buying oils in these kinds of quantities.
In real bulk quantities, we can sell very good hydraulic oils and very good engine oils at very aggressive prices, but it takes this kind of investment in order to be really competitive with high-quality oil. If you have a piece of equipment and we could help with any of the parts that service the oils to go into that equipment, we're glad to help. Here at Messick's, this is what we do. We're available at 800-222-3373 or online at messicks.com.