1. In fall of 2007, we refinished all of our exterior stairs, using
the BioWash system: Stripex-L, Stain Prep, and two coats of Natural
Deck Oil (natural color). The results were beautiful.

2. By fall of 2008, the treads were very porous again. So, we used
Stain Prep and one coat of NDO. Again, the results were beautiful.

3. By spring of 2009, our stair treads and some sections of handrail
were again quite porous. Some residents see this as understandable,
given the two extreme winters we've just had and a big concrete
project in our courtyard which generated a lot of dust and dirt which
no doubt helped sand off the sealant. But other residents are VERY
unhappy and have lost confidence in NDO. Those residents think a
sealant should last longer than one year.

4. We must re-apply stain/sealant before the weather turns, but the
board wants to shop for a more durable product. Perhaps Defy Extreme
is that product? Here are our requirements:

1) We want a product which we can get in a color similar to NDO
Natural, so it can be applied to just the treads and rails.
2) We want a product that can be applied without having to strip off
the NDO by sanding or with a chemical stripper.
3) We are willing to use a Wood Cleaner, in addition to a Wood
Brightener, if that would allow this transition from NDO to Defy
Extreme.
4) We are very hesitant to powerwash our stairs again, as they as
overly porous from too-frequent power washings in recent years.

5. We do realize that re-applying any sealant--even NDO--without
stripping off existing sealant only works if the wood is porous enough
to accept the new product. We plan to test this with a watering can
"tour" of the stairs. If the treads ARE mostly porous, we know from
experience--and from advice from Napier Technologies--that we CAN just
apply a maintenance coat of NDO (after using Stain Prep). But could
we just as easily switch to Defy Extreme?

We would greatly appreciate your advice, Scott!

Q#1: Can we switch to Defy Extreme without chemical or mechanical
stripping and apply it just to our treads and some rails?
Q#2: Will the new Defy Extreme really last longer than NDO?
Q#3: Is there any other product we should be considering as well?

Thanks!!!

I would not switch to Defy Extreme without stripping off the NDO. Prepping the surface is the most important aspect when applying a stain. Also there is not a color in the Defy Extreme line that is similar to the Biowash NDO Natural. When applying a maintenance coat I would only suggest using the same stain.