Mineral oil is a better choice
It doesn't get rancid on a hot boat the way vegetable oil can. And btw, baby oil is mineral oil and can be a lot easier to find. Plus it smells nice.Mike... Granted, the Headmate isn't quite as easy to lube as Jabsco or PH II, but you don't have to take the pump apart to lube it. Just pull the piston rod up, remove the tee handle, loosen the nut around the piston rod and squirt some grease into the pump. It's a bit of a tight fit, so you might have to use a syringe if you can't get any of the tube nozzle by it, and you might have to put just a little at a time in, then pump to spread it each time...but it's not THAT hard to do! I'll never understand why so many people would rather do something that's a never ending job--ok, so it only takes a couple of minutes each time, but those couple minutes add up--when doing it right only takes 10 minutes ONCE each year, and you never have to deal with running out of veg or mineral oil...or forgetting to put any down the toilet till it starts squeaking and becomes hard to pump, which signals that friction is wearing the rubber seals and o-rings. Nobody seems to get any satisfaction out of actually maintaining anything any more...everyone just wants quick fixes--"bandaids"--instead, even when they cost a lot more, are more time consuming in the long run 'cuz they have to be done over and over, and result in premature equipment failure 'cuz they don't work nearly as well. Ah well...<sigh>...it's your boat, your money and your time.