My sincere thanks to everyone who helped me out with my equally sincere question about liquid silicone, which branched out into a question about Pellgunoil and other lubes as well. While I have diligently followed this forum for well over a year and have seen lots of isolated comments about silicone grease, I have rarely even seen a comment about liquid silicone, much less a discussion.
Following one responders somewhat derisive advice, I initiated a number of The Yellow Forum searches under a variety of terms. Unlike the responder, who seems to have found lots and lots of threads, I found only one of any significance other than my own. Perhaps it is because I spell words so much differently. The string I found is at:
There is such a wide variety of opinions, I could spend a week trying to get more data and sort everything out. However, in case anyone other than me has any interest in this topic, here is what I have come up with:
1. I feel certain Pellgunoil is really just Monolec GFS SAE30 engine oil. There can be little doubt because the Crosman Material Safety Data Sheet (MSDS) says so. It can be found at:
Considering the vast difference in price, I feel this information alone was well worth the effort.
2. Some people obtain similar results using synthetic automatic transmission fluid (ATF), and swear by it.
3. Liquid silicone is very powerful stuff, very effect at what it does. The nagging questions are: (i) what does it do; and (i) when should it be used in connection with an air gun, if ever?
4. Some prominent air gunsmiths feel very strongly liquid silicone should never be used for any purpose in connection with an air gun. It will totally ruin the gun in very short order because, no matter where you apply it, it will soon migrate into every nook and cranny of the entire gun. Being a sort of super lubricant, it sticks like glue, is impossible to remove, displaces and repels other lubes, but is a terrible metal-to-metal lube itself. So, no matter where you apply it, it will soon displace any other lube in metal-to-metal contact, resulting in metal galling. Excessive friction results in roughening the rubbing metal surfaces.
5. Some air gun manufacturer manuals say using liquid silicone as a lube will void the warranty.
6. Some users have used liquid silicone for years in a variety of air gun applications with no adverse effects at all.
7. Liquid silicone is an inert, nonreactive, noncombustible super-lubricant for stuff other than metal, making it superb for some applications. Having said that, I know for a fact food grade silicone is universally used to lubricate food-processing machinery.
8. Nothing better for restoring and preserving things like O-rings, gaskets, diaphragms and the like, so long as the item is not itself made from silicone. The liquid silicone would penetrate a silicone O-ring, for instance, and make it too soft. This kind of penetration is great for other materials and, unlike silicone grease, the liquid easily works its way into every nook and cranny.
9. Works great on leather seals, although some people mix it with neatsfoot oil and other people think neatsfoot oil will break down leather over time. Anybody out there own silicone tanned leather boots or use silicone for waterproofing?
10. Works great to protect metals from contaminants. Spreads out, sticks like glue, displaces and repels moisture, body oil from fingers and such. No one questions its use in gun socks, for instance. Apparently, some manufacturers treat the inside of air tubes with it to prevent rust. Someone said it is difficult to re-blue a barrel once it touches liquid silicone, but I read that as meaning it works really well at protecting metal
12. Despite comments to the contrary, liquid silicone can be readily removed by mineral spirits, aka paint thinner.
13. I guess liquid silicone makes a good dielectric for use on electrical contacts, but I am not even sure whether that means it is a conductor or insulator.
Very little of this information has been verified from sources of indisputable accuracy, and I really dont know how to make much practical use of it. All I know for sure is: (i) I will be buying some Monolec GFS SAE30 engine oil as soon as I can find it; and (ii) I will be selling some of the full gallon of liquid silicone I just purchased. I could not find it in any smaller quantity, and I wanted some to experiment with.