@grune said in Opinions on Valve Oils?:
Care to post your opinion/s about valve oils?
re Cass.
FWIW... I have used the Bach oil since time began. Reason; it's fast. But... Bach is petrol based, so it is 'aromatic' and 'volatile': which implies it smells and evaporates quickly, which implies re-oiling every 2 hours or so. Seeking to avoid the smell and evaporation, I tried a bottle of Al Cass Fast, which is 'synthetic'. This Cass is indeed odourless and clear, as claimed. But Cass is not 'fast'. Cass viscosity feels significantly thicker, which causes valve action to be slower and require more finger-muscle. The viscosity makes the valves feel smoother, but at the expense of slower. But it is very much less volatile, so valves feel well oiled for many days. pros and cons.
Synthetic oils have a very low viscosity index (the viscosity doesn't change much with temperature), and they don't change characteristics over time due to evaporation of light ends - unlike the distillates, they don't have light ends.
So their performance is stable over time in a variety of conditions. You still need to pick one with the performance characteristics you and your instrument prefer, but that's for you to discover via trial and error.
I tend to change oil at every use simply as good preventative maintenance practice, so I don't particularly see all the benefits synthetics have to offer, but I still use them (doesn't stop me using up old bottles of distillate oils).
I like Tromba T2 but sometimes hard to locate. I'm perfectly okay with Wicks.