note the color contrast is not due to the water. Its simply the tin cloth. You can still see some of the faded areas... but only in good light.
I used white beeswax (left over from a project) but you can use toilet rings cheaper (a buck fitty per on amazon prolly need about 5-10?) They'll keep your tin cloth on the darker side. But boiled linseed oil is fairly dark as well. I put it on a bit heavy in a couple places, leaving me with some beeswax that needs rubbing off/in. It permeates all the way through. A good process to do every so often.
2 lbs bees wax (2 lbs=1 qt)
2-3 lbs linseed oil (1-1.5 qts)
I've always done 1/3:2/3 mix. But the internet suggest 50/50. I tried that and didn't like it, hardened up almost instantly. Maybe it wasn't hot enough. I heat the mix to about 200. Gives me some good working time. It holds heat very well. I was able to do the whole hood with only 2 heating sessions. You could probably get away with using a kitchen pot if you washed it in the dishwasher on high heat when done. I use a galvanized bucket. So far that has done fine with no incident putting it directly on a burner. But the metal is thin. If I didn't stand right there stirring, it might burn through if I forgot about it.
I was left with a good 2 cups after a very healthy dousing of a very dry and permeable hood. Enough to do a duck jacket I guess.
Linseed oil dries slowly. So, the more you put on there, the longer you have an oily pleasantly linseedy smelly hood. After 1 1/2 days in the sun, its not noticeably oily, but smells of linseed oil. It does leave a residue. I mean, that's kind of the point. It serves as a solvent to draw the wax into the cloth, but it also is a sealant on its own. turpentine can be added as a drying agent. But, really. Not needed unless you were in a hurry. It doesn't hurt it to use it while still drying, other than it gets linseed oil on your paint.
Linseed oil will/can, mildew. Not a problem if its on a rover in the sun or in climate control. But, if I were to park it under trees, in the shade, in the damp. I'd be back to square one fairly quickly. I've had this problem with oilskin clothing in the past. Put it in storage and it better get air. Your old baseball glove in the basement would be exhibit A. If it does start to rot, it can be pressure washed (as mine was) and if you use hot water... well, (A) your hood will shrink but (B) it will rinse out. Put the hood on. Tighten it up and get it wet. It will be back to normal size in no time. THEN Tin Cloth it.
There are other products out there commercially available. This one is very cheap ( you could do it for 20 bucks with toilet rings and a qt of linseed oil) and works better than any other waterproofing I've ever seen. But its not without its drawbacks. If your hood is "leaking" either air or water when buttoned up. This will go a long way in fixing that. Especially in the cold. There's a reason they call it Tin Cloth.