I refinish my deck, quite often like 2-3 times a year. But Im quite picky about the lok and feel of the deck. I like to to always look perfict. I use Boiled Linseed oil.
I started off by Belt sanding the deck with 80 grit. That took off all the deep scratches the fins from wakeboards and Ski's put in the deck, You dont have to do this everytime you refinish your deck.
Then I went to 180 grit with a disk sander (DA sander)
Then I went with 220 grit with a disk sander (DA sander)
I have used finer grits like 400 and 600 to finish it and it comes out so smooth and nice but its hard for the finishing oil to penatrate. So for most people you can stop at 220 grit. But if you want it like a Baby's A$$ go for the upper grits.
Then just wipe on the Boied Lin-Seed oil. The teek soaks it right up then apply a 2nd coat.
Then all you need to do is keep putting the Lin-Seed oil on when it starts to dry out.
Eventually after about 4 or 5 applications of the lin seed oil the Teek will become saturated with oil and and it will need to be lightly sanded down to remove the old oil.
You can use thinners to break down the oil and it will soak into the wood and then you can re-apply some new oil if you dont want to refinish the deck with sandpaper. But it you have any scratches you will jut be oiling right over them.
I like the Deck to look like its oiled but not feel like it has anything like a shelack or coating on it.