: Avoid linseed oil as it id food for mildew!.

I learned the hard way about this, but fortunately, it just led to discoloration and not rot. I didn't know about it until I was told by one of the conservators at Mystic Seaport. He was also the person who told me that salt water was a great preservative and that after a rain, they wash the wooden decks on the boats at the museum with salt water.

: I think danish oil has linseed oil in it but I may be mistaken.

It may vary with the brand, but I'm pretty sure Watco contains linseed oil.

: I use pure tung oil sealer and then a coat or two of tung oil on my SOF frames.

I typically use a coat of tung oil to bring out the color in the wood and help to "glue" the lashings and that's about it. I guess it's really mostly for myself, as I like to see the wood before I cover it.

: A lot of SOF builders do the traditional thing and don't use anything.

All oiling does is delay the inevitable discoloration. The more the boat gets used, the faster the wood changes color.