New Cedar Deck - Can't get the Gray Out!!

[Norman99 14]

Hi – Could really use your expert opinions

I have a new cedar deck (about 500 sqft) that was installed too late last year to stain. I cleaned it before winter set in and let it sit. Obviously it weathered and grayed. No big deal right? Well I’ve cleaned it twice with Benjamin Moore Restore (10% Sodium Hydroxide, 5% Citric Acid) 5:1 ratio. There are still patches of gay on most of the boards. 1^st cleaning was applied with a brush, sit 15min, and removed with a brush and garden hose. 2^nd cleaning was applied with a sprayer, sit 30min, and removed with a brush and garden hose.

What am I doing wrong? I’ve scrubbed a few boards hard enough to bring the fuzz up and tried a brightener on a couple of boards with no luck.

I’m worried any stain applied will not look even over the gray patches not to mention would not likely adhere to this dead wood.

Planning to try sprayer, 30min, remove with pressure washer (low setting) this evening

Any help is greatly appreciated – can supply pics if needed

Thanks,

Mike

[David Phillips 14]

Hello Mike,

Glad to see you are really taking the time to try and do the job right. When it all comes together, it will be well worth all your hard work.

To me it sounds like the product you are using may not be getting the job done. I'm not familiar with the BM cleaner. Is it a one step product that contains both sodium hydroxide and citric acid? The cleaning process should be done in two steps. First a quality cleaner is applied (usually a sodium hydroxide or sodium percarbonate) then gently pressure washed off. The second step is the brightener (usually an oxalic or citric acid) which neutralizes the cleaner, restores a proper pH and gives you a bright better than new wood color. There are several great wood cleaners out there, and they will do all the hard work for you. If by some chance what you are using is a one step product, that is likely your problem.

[James 625]

The grey your seeing will not come off with any cleaner. The wood has degraded a bit and change color but not enough to come completely off. Cedar 6 months old you can just bleach it and rinse with no pressure. You need to buff it off with a 3 m pad. Sanding is a bit much .

[Norman99 14]

Guys appreciate the replies,

Well the 3^rd cleaning went no better than the first two – pressure washing off the BM Restore proved no better. Still lots of gray patches. Wisely, I only did a small section.

Dave, BM is a two step process but your right I had the chemical mixture mixed up. The Restore is 10% Sodium Hydroxide and 5% Silicic Acid solution. After that you apply the Brightener \ Neutralizer 10% Oxalic Acid and 5 % Citric Acid.

James, so if I understand correctly, some of the wood is essentially not “dead” enough to be removed with chemical? Is the 3M buffing pad the one used in floor polishers and would I use it wet or dry? Also, will it actually remove the remaining gray patches or will it only smooth it out enough for staining? If the latter is the case I’m concerned about the look and endurance. Also, do you mean I should have initially used a chlorine based bleach instead of an oxygen based bleach (sodium hydroxide)?

Thanks again guys. Sorry for all the follow-up questions but I’m kind of at wits end here.

Mike

[James 625]

Bleach works better on newer cedar. Better off buffing it dry until you get good at. Yes ,3m floor pad. You can cut them to size. There are some other pads similar to 3m used on wood . In the sanding department of a hardware store.

If you do oil it in its present condition it will be a little blotchy looking but not bad looking.

Did you fur up the wood or is it just grey blotchy areas? I ask becaused you used sodium hydroxide .

[Norman99 14]

Actually, now that the area I did with the 3^rd cleaning has had a little more drying time it doesn’t look too bad, Still a few gray patches, and a bit of fur where I got a little too close with the pressure washer. But, a light sanding seems to take both of these off.

James, yes the wood did fur up a bit with the sodium hydroxide but only in places where I scrubbed a little too hard. Going to try a section with a chlorine based bleach this morning to see if that helps any. If not I’ll probably go the route of the 3^rd cleaning and then try and find a 3M pad I and polisher at my local hardware (not holding breath)

[Adrian 155]

+1 with James.

[James 625]

Don not use bleach now it's to late !!!!!!! You will cause more problems for your self. You done too much already just buff and move on. If you did you bleach you probably furred the wood more. Oh well.............

[Doug Black 18]

That Benjamin Grey Restore is lye and silicic acid, which is similar to sodium silicate

The latter is not really an acid. Note the PH Controlled stabilisation of silicic acid below pH 9 using poly(1-vinylimidazole) - Journal of Materials Chemistry (RSC Publishing)