help with cedar deck finish

I built a small deck last year with some beautiful reclaimed western red cedar. I prefinished everything with Penofin. Less than a year later it looks like $hit. Store told me to wash off the black stains with oxy clean. It works but takes off the finish too. I am totally willing to spend some $ for the good stuff (thought I did). Any recommendations for refinishing?

oh yes. what looks like crap now? is the stain fading, peeling, or just wearing off?
did you use the blue can or red can penofin? do you have a preference between something with or without a sheen? how is the weather there around now (temp and humidity)?


here's the short story:
since you have a transparent, oil based stain on there now, your best bet is to stick with oil.
if you want to use a different transparent stain, you'll have to remove all of the penofin, either by sanding or by the use of a chemical stripper.
if you don't want to remove the penofin, you'd have to go to a semi-transparent or semi-solid stain, also oil based.

I use Sikkens DEK. Works great, looks great, holds up to the Pacific Nortwest Coastal environment. http://www.sikkens.us/en/Products/Decks/Pages/CetolDEKFinish.aspx

Dunerunner said:

I use Sikkens DEK. Works great, looks great, holds up to the Pacific Nortwest Coastal environment. http://www.sikkens.us/en/Products/Decks/Pages/CetolDEKFinish.aspx

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good call, exactly why I asked about the sheen. one of the best products for decks around. One cool thing is that you can use their Cetol Maintenance product periodically, so you don't have to do a full on refinish as long as you keep up on it.
it is supposed to be applied to all six faces of every board, though. if you can get the top, bottom, and sides, it'd probably be OK, but if there was ever an issue, sikkens wouldn't cover you.

their SRD is pretty good as well, but you'll probably be looking at 2 years between maintenance coats. quite a bit cheaper than the DEK though.


big thing most people don't realize is to let your deck dry out really well if you pressure wash (around here that's anywhere from 5 days if it's frying hot to about 2 weeks in the LATE spring/early summer)

EDIT: i completely skipped over your black spots. those sound like mildew spots, which is usually from applying your stain when the wood is wet, or from excess moiture trapped below the deck (deck too close to the ground without proper ventilation) TSP and bleach will take care of that way better than Oxyclean. 30 seconds cleaner is a convenient pre-mixed tsp/bleach solution that's usually pretty inexpensive, find it at the Ace or true value - home despot and bLowes don't sell it.

Thanks for the help guys. Here are a few pictures that may shed some light:

Here is the deck:


Here is a shot of the black staining:


Here is where I tried the Oxy on the steps and skirt board. It still has some color but it seems to have removed a lot of the finish.


This wood stood 60 years as football field lighting posts. I had it sawed and it seemed bone dry then plus it sat for a year indoors before I even used it. I prefinished everything with two coats and it sat in a nice warm garage for at least a few weeks before it was installed (so I dont think moisture under the finish was a problem). I do want to stick with an oil based finish. I am going to get some TSP today and see how that works. Any other suggestions?

I've used a powerwasher on our treated deck. Not sure how that would affect the Cedar. Seemed to clean ours up pretty good. Almost like new. I'm sure you'd at least have to be careful of the amount of pressure.

Homercidal said:

I've used a powerwasher on our treated deck. Not sure how that would affect the Cedar. Seemed to clean ours up pretty good. Almost like new. I'm sure you'd at least have to be careful of the amount of pressure.

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Good idea. I am going to try the pressure washer. I have some Oxalic acid and am going to pick up some TSP and experiment a little.

The finish has really faded and does not look close to what it looked like last fall.

From a previous post:
It was the blue can. That is all the local store had.

I'd test an inconspicuous area first... TSP is supposed to be good for cleaning stuff like driveways, but I don't know what it would do to wood.

The powerwasher we borrowed worked so well that I am considering buying one for myself. Just be careful that you don't carve the wood. The washer I used could be dialed in to a tight stream and you could actually remove a fair amount of wood with it. Start low and work your way up. A small deck like that should not take too long. I bet you could rent from for not much money. And it might work best with a chemical pre-treatment (less pressure, better stain removal).

Homercidal said:

A small deck like that should not take too long. I bet you could rent from for not much money. And it might work best with a chemical pre-treatment (less pressure, better stain removal).

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Are you saying your deck is bigger than my deck? I always thought it was how you used your deck, not the size, that mattered I have a nice pressure washer...I just kind of forgot about it.

Homercidal said:

I'd test an inconspicuous area first... TSP is supposed to be good for cleaning stuff like driveways, but I don't know what it would do to wood.

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TSP and bleach is pretty much the industry standard for cleaning wood prior to staining. it's what Sikkens recommends in all of their staining brochures and all of their training classes.

do be careful of that glass though, TSP is darn near impossible to get off of glass.

that picture looks les like mildew than your description, are there little black specks in there that aren't coming out in the photos, or is there just general discoloration? looks like just algae/general grime or UV damage. your boards are very close together, does the deck have any pitch to allow for water runoff?

if the TSP/bleach and/or pressure washing don't clean that up, either a floor sander or a wood brightener containing oxalic acid will get it back to bright.

for my own info, which penofin did you use? blue can or red?

lschiavo said:

Are you saying your deck is bigger than my deck? I always thought it was how you used your deck, not the size, that mattered I have a nice pressure washer...I just kind of forgot about it.

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Bigger is generally better, but you can get tired of taking care of a bigger deck, especially if the whole neighborhood gets to use it. That may be what you're after though. If I had a big deck, I'd want to show it off and share it.

I'm not saying my deck is bigger. I also washed some other stuff, like a swing my wife procured. After I got it all washed, turns out she is not much of a swinger. isn't that how it usually goes though?

I used a brand called "in Wood" from HD. This was the procedure I used and my finish lasted for over 4 years here in the PNW. Get the old finish off, spray with 10% bleach solution, let sit for 24-48 hours, pressure wash, let dry for several days, apply finish. Good luck.

Homercidal said:

Bigger is generally better, but you can get tired of taking care of a bigger deck, especially if the whole neighborhood gets to use it. That may be what you're after though. If I had a big deck, I'd want to show it off and share it.

I'm not saying my deck is bigger. I also washed some other stuff, like a swing my wife procured. After I got it all washed, turns out she is not much of a swinger. isn't that how it usually goes though?

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You must not have seen blue collar comedy "Big Decks". I don't know how to link it on my phone.

Just an update in case anyone is interested: I washed the deck with bleach and TSP. 1 quart bleach, 1 cup TSP and 3 quart water. I applied that with a garden sprayer let sit 20 minutes and scrubbed lightly with a brush. Then I used the pressure washer to rinse. Waited a few days and checked the moisture with a meter reading was 8%. Re-applied Penofin. It looks like new again...I am happy.

I think I just waited too long for the new coat of finish. I read on Penofin website that it should be reapplied within 6-9 months for flat surfaces. I guess I will start doing a spring and fall application from now on.

I'll have to remember that. I borrowed a sprayer year or so ago and it looked ok then, but back to being faded and crappy. I missed my chance at treating it.

the time really depends on the deck. the quick and easy test is to sprinkle a little water on the deck, if it absorbs, it's time to reapply. if it beads, you'rs still good. remember that maintenance isn't all-or-nothing. you can do a few boards or the whole thing, depending on need.

lschiavo said:

Are you saying your deck is bigger than my deck? I always thought it was how you used your deck, not the size, that mattered I have a nice pressure washer...I just kind of forgot about it.

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Wait a minute. You have a nice pressure washer? And I didn't even know, let along borrow it? I KNEW you were my cool friend with all the tools!

lschiavo said:

Just an update in case anyone is interested: I washed the deck with bleach and TSP. 1 quart bleach, 1 cup TSP and 3 quart water. I applied that with a garden sprayer let sit 20 minutes and scrubbed lightly with a brush. Then I used the pressure washer to rinse. Waited a few days and checked the moisture with a meter reading was 8%. Re-applied Penofin. It looks like new again...I am happy.

I think I just waited too long for the new coat of finish. I read on Penofin website that it should be reapplied within 6-9 months for flat surfaces. I guess I will start doing a spring and fall application from now on.

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How long do they recommend that you do a spring and fall application? That seems like an awful lot- it's expensive, isn't it?

Yooper said:

Wait a minute. You have a nice pressure washer? And I didn't even know, let along borrow it? I KNEW you were my cool friend with all the tools!



How long do they recommend that you do a spring and fall application? That seems like an awful lot- it's expensive, isn't it?

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maintenance is a life of the deck thing. it's done as often as it's needed until you don't want a nice deck anymore.

when last i sold it, penofin was about $32 for the standard grade and $40 for the ultra grade.

bengerman said:

the time really depends on the deck. the quick and easy test is to sprinkle a little water on the deck, if it absorbs, it's time to reapply. if it beads, you'rs still good. remember that maintenance isn't all-or-nothing. you can do a few boards or the whole thing, depending on need.

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This is true. Even with the state my deck was in, the boards closest to the house (less sun and water) were not in bad shape. The stairs were terrible getting all the traffic and no cover.

I missed a few of your questions earlier. Yes the deck has a slight pitch from the house. I never see any water pool. I tried to install the boards properly for cupping. Spacing is 1/8-inch. I used those tiger claw fasteners...not sure what I think of them. Tip: place the board first and then cut to avoid knots...found that out the hard/wasteful way.

Yooper said:

Wait a minute. You have a nice pressure washer? And I didn't even know, let along borrow it? I KNEW you were my cool friend with all the tools!

How long do they recommend that you do a spring and fall application? That seems like an awful lot- it's expensive, isn't it?

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You never asked. I own 1/3 of a lot of cool tools. I go in with my dad and brother on major stuff. Its a great arrangement.

The penofin is $35 or so. One coat on the freshly cleaned deck took less than a quart surprisingly. If that holds true a gallon should last 2 years.