Uses in beekeeping
Commonly called "Vaseline" after the trade product
Petroleum jelly is something that is probably in all households and used for a large number of purposes. A websearch will reveal that the raw product from which it is refined was discovered on oil rigs in 1859. The original and best known brand is "Vaseline", although there are many other "own brands" or similar that are simply packaged as "petroleum jelly" that will be suitable for beekeeping purposes.
Beekeepers are often advised to smear petroleum jelly on the mating surfaces of bee hive parts. It is said to stop the bees gluing everything up with propolis, making manipulations quicker and causing less distress to the bees. It also helps when cleaning equipment as the previously "Vaselined" surfaces are much easier to scrape.
On an earlier page Dave Cushman wrote "To enable petroleum jelly to penetrate the surface of the woodwork that it is applied to, it should be thinned down with a volatile solvent, white spirit is a suitable solvent. Using a solvent allows a smaller amount of petroleum jelly to be applied, which makes the surface less slippery, but still stops propolis from adhering to the wood fibres.
I have to be honest and say I have never used petroleum jelly to coat hive parts. Neither have the vast majority of beekeepers I have known with more than a couple of colonies. I find it easy enough to scrape propolis off wood and metal work with a good flat hive tool. I have come across many beekeepers who have advised it, but either didn't use it themselves or had soon given up. I think it is one of these things that sounds a good idea and gets handed down as "standard advice". If you want to use it then do so, you won't do any harm and it's personal choice, but I haven't found a need to.
I do use a light smear of petroleum jelly on the bottom end of the spindle of my honey extractor, where it fits in the bearing at the bottom of the drum as a lubricator.
I don't use acetic acid for sterilising, but those who do will know that acetic acid will very quickly rust steel parts such as frame runners and castellated spacers. The usual thing to do is to remove them, but I think a smear of petroleum jelly over the surface will avoid this.