Water or Oil - does it mix or is it like Oil and Vinegar?

I've been posting my progress in the Beginners section of the forum chronicling my progression going from a disposable back to my 40 year old Safety razor and then to my 40 plus year old Straight Razor.

Last night, in preparation for what was my first - in over 40 years - Straight Razor shave this morning, I honed my Straight Razor - unlike you modern guys I own a Norton Bear Compound oil stone that I bought back when I got the razor, that's what I used back then, so that's what I used last night.

I believe the finish side is the same grit of the Norton compound water stone that seems to be so popular nowadays.

I'm thinking of buying a water stone but for now will continue to use the oil one.

Does anyone have any thoughts on why a water stone is better than an oil one?

I wouldn't say one's better than the other imo, It's more personal preference. Water, Oil, they both help to lubricate the stone, and float away the metal particles. I use both from time to time. I use an old Norton Coarse/Fine oil stone religously in work to sharpen knives. It puts a very nice edge on a knife. It will shave arm hair. If you like it, and enjoy the shave, that's all that matters.

If you want to venture into water stones, I'd recommend the Norton 4/8k. They also make a nice 220k/1k and 4/8k w/flattening plate. The water stones do need to be lapped flat prior to use, and checked for flatness periodically.

We have had these discussions before and historically as well as in our discussions oil stones have always been a no no for straight razors. Honestly, I don't remember why. I know over time the oil will soak into the stone and getting it out is close to impossible (notice I said close) depending on the porosity of the stone. It may have to do with keeping the stone surface fresh and clean during honing which an oil stone won't. That's my guess.

If yours is an combo oil stone, than it is unlikely to be anywhere near as fine a finisher as the ax mans favorite Norton Razor Hone.
That does not mean you cant use it to sharpen a razor, just that it wont be a finish stone. As far as I know the smoothest Norton combo oil stones were at best 2-4k in grit. Others here will have way more accurate info than me.