On Friday, January 11, 2019 at 3:04:10 AM UTC, Mark J. wrote:

Q1: I don't use thread compound or linseed oil, and would rather not
start now. I lubricate threads and nipple/washer contact with light
grease.

The special feature of linseed oil is that it is a "drying oil", more particularly a "slow drying oil", so it will give the thread/nipple/rim interface lubrication during assembly, and then slowly reducing flexibility to settle in for a considerable period, up to six months, and over this period slowly evaporate to leave a residue that will eventually lock the joint. So linseed oil acts as thread locker but one working gradually, with reducing flexibility over time. Grease won't do that.

Linseed is fairly heavy oil. Other, lighter, drying oils include safflower oil, poppy oil, and walnut oil. You can get them all at any good art supplies store as they are used by oil fine art painters. But walnut oil from the supermarket is just as good and about a quarter the price of the art supply walnut oil.

Note that not all natural oils are drying oils.

I tried them all when I rebuilt wheels that arrived shoddily built from Gazelle. They all worked equally well and the wheels were still good and tight when I stopped riding that bike because I had a new favourite.

Read the labels in the art store carefully before you make your choice. You don't want any oils with resins in them: they dry fast and set hard. You may or may not want siccatives in your oil: they speed the drying but do not set hard like resin. You do not want volatiles (turpentine, white spirits) in your oil because they speed evaporation. If you go for the supermarket walnut oil, buy the one with the fewest additives, and don't buy any that are blended with other types of oil, because the other oil(s) could cause unforeseen effects.

***
You could even use ingredients you find in your wife's kitchen to make a very passable substitute for a drying oil. As Le Grande Jobst informed us, water is a lubricant. And your wife has raw eggs and olive oil in the kitchen.. Separate an egg yolk from the white goo. Discard the white stuff or feed it to the cat. Mix the yolk with twice its volume of olive oil, until it forms an emulsion. Keep the emulsion in the fridge in an airtight bottle because it will dry sooner than you can finish the wheel. Take out only enough to use in say half an hour. Add water to a small portion of the egg/oil emulsion until it flows like thin cream. This is what you use. The water and oil will lubricate the construction of the spokes into the wheel, and the egg will set over a period of weeks as first the water and then the olive oil evaporates, but after a couple of hours you will be able to move the spoke, so this is a faster process than any of the oils above, than even the resin. Basically, this is egg tempera (like artists used as paint until midway through the Renaissance) or more precisely tempera grassa, minus the pigment. I haven't tried it on bicycle spokes but I've used it on kaolin clay boards, and it makes a good hard surface.

Andre Jute
Sometimes I wish I paid attention in Chemistry class