Someone replied to a thread I posted elsewhere and said "Ask those guys over on the Boat Building forum - they know about water proofing wood. SO here I am.
This was my original post:
I am building the wood bed for an old pickup.
I have oak ready to put a finish on. I believe it is red oak.
I sanded it with 80 grit and then finished it off with 220.
I want to use 100% tung oil but don't know much about it. SO I guess I need someone to tell me some about it.
From some info I "read" you can put the first couple coats on with it thinned 1:1. (I assume with it thinned it will penetrate the wood better??)
I have no clue if the tung oil will color the wood or how much. I assume the more coats = the more color.
SO there you have it - that's pretty much the limit of my knowledge.

I want to use tung oil to avoid using any sealer that may chip / peel off later on in years to come forcing me to have to take the whole bed off and refinish it. I heard the the more coats the nicer it looks and more waterproof it makes the wood.
I heard you can keep adding tung oil to put moisture back into the wood instead of having to take it off and refinish it on down the road?? True??
I'm working on making a street rod / show truck and want a super finish on the bed and something water proof.
Also I was thinking about actually using some sort of sealer on the bottom of the boards that will be exposed to water; mud; grime, etc. I thought maybe it might help prolong the life??

There you have it - feel free to correct any of my misconceptions and add any info I need.
THANKS