Episode 2: deck prep, mixing, and application.

We had a good rain, which was a good time to clean the deck (16' x 16'
redwood). I used a deck wash, following the instructions. As usual, I
wasn't impressed with the results, but that's what everybody
recommends... Let it dry for 6 days. Weather note for my location: at
this time of year it's usually dry with low humidity, daytime highs in
the 70s and nighttime lows in the 50s.

I started with Behr semi-trans oil-based deck stain from Home Depot,
exactly the same stuff I had used in 2007 (after sanding the whole
deck down) with unsatisfactory results (see previous threads). The
label says it has 550 g/l VOC. This seems pretty high, considering the
VOC limits elsewhere (especially in California). But it produced
almost no water repellancy, even with a 2nd application 2 weeks later,
and pretty much just disappeared from the heavy sun & traffic areas of
my deck after only 1 year. I've re-stained the deck every 2 years
since it was built, so I know what it should look like.

Using my proportion formula from episode 1, with zero-VOC BLO and 791
g/l VOC mineral spirits (MS) and the 550 g/l VOC target, I got
proportions of 0.695 MS and 0.305 BLO. That's more than 2 - to - 1
solvent to BLO as the allowable max. This seems higher than necessary,
judging from the recipes I've seen for other applications. So I went
with a 50 - 50 mix. Pure guesswork.

Next question was how much of this mix to add to a gallon of stain. A
gallon is 16 cups. I guessed that half a cup would be a conservative
starting point. That's only a hair over 3% of a gallon. By comparison,
a lot of applications are ALL BLO and MS, so maybe I'm being too
timid...

Compatibility: it mixed in perfectly, as far as I could tell. No
visual indications of any separation, even after several hours of just
sitting.

Separate issue: I also added a packet of mildewcide. Krud Kutter from
Ace Hardware was the only one I found locally, at least in the 1-
gallon size. Its online MSDS says it's a viscous liquid; what I got
looked like something between toothpaste and putty. Maybe it was just
very old... I squeezed it into the mix and it didn't dissolve or
disperse, even though the label says it's good for ANY paint. I
stirred the hell out of it, but only managed to reduce it to very
small blobs. So this part was probably a waste of time and money. I'd
try another brand if I ever do this again.

Application: with a long-handled 1/2"-nap roller, making sure that the
stain filled any cracks and screw holes completely. I only did the
horizontal surfaces at this time; I'll get the verticals and in-
between the deck boards later. The verticals merely dry and fade with
time, and I only do those every 2nd or even 3rd staining. For in-
between the deck boards, I've found that the fuzzy paint pads WITHOUT
the holder fit nicely, although it can get messy. If I'd been thinking
better I would have done that first, but I was eager to see how the
main flat area would do...

My deck has areas of different combinations of traffic and sun
exposure. Some sucked up the stain immediately, others probably could
have been skipped altogether. I did the whole thing anyhow. So on day
one there are dull areas and glossy areas. I'm not too worried about
that; blowing dust and/or rain will take care of the shine eventually.
From previous experience, these areas will dry at different rates. If
I recall right, it'll be about 5 days before there's NO perceptible
stickiness anywhere, even with an un-doctored stain. We'll see how my
modified version does. Stay tuned.