Finishing a Weathered Platform

[Dan R-M]

After reading Jeff's post on his platform I'm inspired to solicit some opinions on platform finishing.
We've got a nicely-weathered platform out there (the "heavy duty tarp" has outlived its water-repelling lifetime) and my plan is to take a few days before setting up the new yurt to 1) sand the t&g reeaaaal good and 2) give it 3-4 coats of polyurethane.
What have people's experiences been with this kind of process? I just think it makes a lot more sense to get the nasty stuff on and cured before enclosing it. I'd do this over a stretch of nice days, of course.

[Pacific Yurts]

Dan,

I would remove the drip edge from your platform and rent a large walk-behind sander. This will make the job of sanding the old platform much easier. After it is sanded and the dust removed the drip edge can be re-installed and the clear coat applied. If you have some nice weather it is much easier to apply the finish prior to assembling the yurt. You can tape some drop cloths down to protect your beautiful floor during the yurt installation.

[Robo]

I've been a carpenter for forty years. I used to occasionally see pro wood flooring guys use their HD sander to level and finish sand new redwood decking on very high end homes. The sander whistles through new redwood. The finish applied to such a surface sticks great and looks incredible.

Based on that, I'm gonna say a HD pro floor sander will certainly do a good job leveling out and removing the marginal wood surface of a weathered deck. But, how is the framing underneath? Hopefully you have decent framing underneath that isn't rotted. That is a big deal for 'purchase' of nails and screws.

If wood 1/8th inch down isn't cracked too badly, you could try sanding a few marginal spots on the deck with 40 grit on a small hand held belt sander to help decide if it is worth renting a HD pro sander.

Also, make sure you get your fasteners set 'deep' before you set to with the sander. I also suggest screwing off the decking with 3" gold coated screws.

Polyurethane is the industry standard for floor finish. Three or four coats will do you good. Make certain the yurt cover stays on year round as urethane finishes degrade in sun and weather.

Good luck.

[Dan R-M]

Thanks PY and Robo. My father-in-law gave me the advice that a belt sander would be tediously slow, so a floor sander rental is definitely in my future.
The deck sits on some heavy-duty treated lumber, as per PY's platform instructions, and we used coated deck screws for fixing the t&g down. Guess it would be a good idea to make sure they're good and countersunk before sanding, though!
Anybody got general advice for filling big cracks? The "a" side of the t&g is what I faced down, since it's beveled. The "b" side is mostly great, but the not great parts are extra not great.

[Robo]

Auto body bondo will fill big gaps and cracks in wood.

[Jafo]

As long as the cracks are not TOO big, you can take some of the sawdust you are about to make with your floor sander and mix it with wood glue to make a filler that will match your current wood color perfectly. I do this with furniture all the time.