1) i'll be getting GPL 206
2) the _greases_ all have the same viscosity. this is given as their NLGI. however, the greases are basically a matrix of ptfe powder with oil embedded in it. the _oil_ in the matrix varies per the formulation number and that base oil has different viscosities with different formulations even though the greases all have the same NLGI of 2 (peanut butter).
so this begs the question: how do they achieve the same NLGI using wildly differing base oils? a-hah! it's quite simple: you just vary the amount of PTFE. in exchange you get different material properties (that aren't viscosity) with each grease but exactly the same viscosity. the way to read the datasheets is that the lower GPL 20xs are more volatile (the base oil is more likely to vaporize, leaving only the ptfe matrix), and the higher GPLs 20xs are less volatile, but naturally the oil dominates the mix more than the ptfe matrix.
however, keep in mind that krytox is generally VERY inert, so the scale really goes from "not very volatile" to "THIS OIL WILL NEVER VAPORIZE EVER". now here's the problem with volatility in a keyboard switch. if the oil does vaporize, it will get _everywhere_ it will get on the contacts. it will get all over the inside of the keyboard, etc. etc. and if you remember from previous posts, NOTHING DISSOLVES KRYTOX (except for more krytox that's been formulated to break the polymer chains, actually. it's cool but very expensive to do this).
the volatility is based largely on temperature, so the worst case is that you leave your GPL 201'd board in a hot car and the oil in GPL 201 actually has a chance of off-gassing at hot car temperatures. that's not good. so, i erred toward the "WILL NEVER VAPORIZE EVER" direction for everything, and the dupont chemist agreed. the other nice thing about this is that the oils and greases i will be selling will be useful in the maximum number of applications. you can run them in bearings and bushings at 200C no problem. they will be slippery as crap and won't go anywhere.
OK, that said, people like different viscosities of grease, right? A-HAH, the 1506 oil is really particularly cool in that it has insanely high vaporization criteria, just like the GPL 206 grease. however, the oil viscosity is actually really low. why? because it's been formulated in a special way that makes it appropriate for use as a vacuum pump lubricator. it also makes it absolutely perfect for our application. you can use it to thin out the GPL 206, BUT it doesn't change its vaporization characteristics in any negative way like GPL 101 or 102 would. In fact, it is actually _less_ prone to vaporization than the base oil in GPL 206.
BAM! optimal application for our use case
