amarango

So refreshing. Hitting hard, songs about drinking beer and rum.....reminded me of days gone by. So raw, and yes, 13ish spirit....

@Happymtbfr: Great to meet a materials science bro. Now that you mention it, mineral and PAO synthetic oils are a bit close to PFTE solubility parameter for comfort.......will look into it. Actually, I said 10, but it is more like 7-9, like you said.....WPL oils are very far away from that region. You bring up a great point about the effective Hildebrand solubility parameter of the combination of ingredients. On the other hand, you can just plop a seal into the oil and see if it swells....

70% oil and 30% additives.....

String of pearls (mineral oil), fuzzy rope (PAO), stars (triglycerides), still working on monoesters......just remembered that stars have 5 points, not three. Need a 3-point structure found in nature to describe our oils.

Good point and that would be a good source of oil for sure. However, not all oils are the same and the ones from human liposuction clinics contain a lot of saturated fatty acids, which would make your oil crystallize at pretty high temperatures, (think of butter or lard).....imagine that in your suspension. Maybe in Dubai (hot!) it would fly. Love fight club, but no go.

Thank you. Main motivation is, for example: Of the 1.4 billion gallons of lubricant oils used in the U.S. every year, 40% is lost due to evaporation or spillage into ground and waterways. That is way too much for me.....you even wonder where does the "properly" disposed oil go to?

Alex here....so, here comes the geeky answer. There is a parameter the scientists like Hildebrand and Hansen developed which characterizes the "chemical nature" of a polymer (elastomer). They were interested in predicting if a certain polymer was soluble in a particular solvent. The treatment is not difficult and it comes down to "like dissolves like". Like water does not dissolve oil but a mineral spirit does. So, if the chemical nature of the solvent is similar to the polymer....wham....it starts swelling and eventually dissolving, losing tensile strength, going to hell. What you could also do is washing out "plasticizers" which are added to the polymer to make them nice and soft and then your seals turns hard as a rock......not good. So, here it comes....if the absolute difference in HIldebrand solubility parameter between the polymer (elastomer) and the solvent (suspension oil) is greater than 2, then they are compatible. This is based on experience and testing. Now, which elastomer you say. Let's assume that all seals are made of NBR (Nitrile butadiene rubber under trade names such as Nipol, Krynac and Europrene), there is NO PROBLEM AT ALL since this elastomer has a solubility parameter of greater than 20, while WPL oils have a solubility parameter of about 15-17. So, we are all good. Having said this, let's pay tribute to mineral oils and PAOs which have Hildebrand Solubility paramters around ~10. However, this analysis will depend on the type of polymer that you use....natural rubber (NR), styrene-butadiene rubber (SBR), epoxidized natural rubber (ENR), ethylene propylene diene monomer (M-class) (EPDM). You could just look up the value of the respective polymers and judge by yourself (all in interenet). But I think most manufacturers are using nitrile rubber, so, we can pretty much be cool about the whole thing. If we are talking about natural rubber....then we may have problems. Does this help?