"HotRdd" wrote in message
1) I've reclaimed some old and heavy 10" x 10" posts from a barn that I'm
hoping to use to give the deck some character, does anyone see any
problems using this structurally?

Nope, should be very strong



2) What type of sealer should I use to treat this old
lumber.Recommendations

I'd use some sort of oil like Penofin


3) I need to bury some posts this weekend and I'm not sure what the best
method is. Do you get a concrete tube and fill it full of concrete and
then put the post on top or do you encase the post in the concrete? WHY?

4) Should I stick with treated lumber for the posts?

You fill the hold with concrete and use a mounting braked for the post.
Structurally, the concrete and post will perform well and the bracket serves
two purposes. It keeps it lined up and more important, keep it from ground
contact and wicking up water to rot it away. Your 10 x 10's may have
character, but are more prone to rot than a pressure treated post.

If you are in the process of starting a deck, you can get a lot of
information on brackets and fasteners at www.mcfeelys.com