Have a deck restoration job coming up and I’d love some other perspectives. No pictures yet…
Here’s the rundown:
880 sf of cedar deck
115 lf of railing (2x6 cap, 2x2 pickets, 1x4 rails top & bottom)
2 sets of stairs; one 4 step and one 9 step (standard width)
500 sf of lattice below
The deck is about 7’ off the ground on end, and 3’ off the ground on the other

560 sf was the original deck and was sealed with Sikkens. It wasn’t clean or brightened beforehand, but a sealer was applied on new lumber. It’s peeling quite a bit and looks pretty bad.

An additional 300 sf was added, and never treated

Talked with Joe at the Sealer Store, did a fair amount of reading as I'm still getting familiar with chems, and here’s my plan so far (gonna call Bob tomorrow to get a second opinion! Thumbs Up):
1) Lightly sand the entire surface
2) Apply Defy wood cleaner with pump up sprayer
3) Rinse clean with pressure washer
4) Maybe repeat for old stain
5) Apply Defy brightener with pump up sprayer
6) After a couple of days, apply sealer with a stain pad
Questions I’m trying to answer so far:
1) What are the selling points for TWP or Defy sealers over something like Thompson’s water seal?
2) I've read that I could apply F18 & F10 vs the Defy products? Advantages or disadvantages to each?
3) What would you use for sanding? I read one post about an Osborne brush. Any more details on these?
4) What method do you prefer for applying sealer to vertical surfaces? Spray then wipe with a stain pad?
5) How would you clean and wash the lattice (he has storage items behind it)? Same as the deck?
6) How would you clean the belly band around the deck. It seems hard to reach.
7) What are your techniques for keeping the sealer off the siding?
Thanks!

Sikkens is very hard to remove and the Defy wood cleaner will not do the job. You will need a "wood stripper". You may also need to strip a few times to get off the sikkens. Sanding should be done after to remove the stain that did not come off when stripping.

The Cetol formula is a film forming "varnish" type stain. In some cases it may be impossible to remove. The SRD formula is easier to remove but still can be a challenge.