I have leather gloves and mittens and I want to waterproof them. I usually use mink oil on my leather boots to condition and seal them, Can I do the same for gloves and mittens or should I use something else?
I have had the best results "waterproofing" gloves using Snow Seal which is a wax like product. Putting the gloves in the dryer for a few minutes before you apply the wax seems to help in getting good absorption and the gloves need to be as clean as possible. This only works for smooth leather gloves.
I don't think there is any magic product though, if you've got something that works well for leather boots, and you know how to use it effectively then using that for gloves makes sense to me. Leather is leather after all. The one advantage Snow Seal or similar wax based products might have is improving the grip of the gloves.
There's a tradeoff: Sealed leather doesn't let water in, but doesn't let water vapour out either. This results in liners getting soaked sooner.
You can reduce this somewhat: Apply your choice of goop to the inside face only, but include the web between thumb and palm. If you do gloves, do about halfway around each finger, leaving the backside ungooped.
Another way to keep your hands less damp is to apply antipersperant to your hands. (This also works for feet.) It takes about 3 days of use to reach it's max effect.
In sloppy wet conditions I prefer coarse knit wool liners. Wool retains a certain amount of warmth wet, and coarse knit doesn't mash down as much. For colder conditions, fleece is warmer as it doesn't hold much water.
In either case, one useful trick: Carry multiple sets of liners. Yes, the outers will get the fresh liner damp, but you will have some time before it gets soggy.
Note too, that with time, your blood circulation in your hands will adapt. I've seen winter fishermen on Lake Winnipeg working bare handed in below 0 (C) temperatures, and put their hands into the lake (at 0) to warm them up. This adaptation doesn't happen quickly.