Weathered Redwood Deck

[GumDestroyer]

I have a sun damaged and darkened old redwood deck to restore. It has been stained in the past. It looks now like a completely greyed out cedar fence. The customer is moving and selling the home and would like me to re-stain this deck. He said he is not too picky but would like it presentable for resale. I plan on coating with a dark stain afterwards.

Would you...

Apply sodium hydroxide for the old stain removal and then neutralize and brighten with oxalic or recommend a different method in this case?

 

[GumDestroyer]

Update: No Pics...(3yr. old son) has borrowed camera....ahhhhh!

 

[GumDestroyer]

Decks are a new animal for me as I mostly do building washes and flat surface cleanings. So is Sodium Hydroxide for stripping painted decks or stained decks or both? I suppose one for stains and one for paint and one for oil based and one for latex? Ahhhhh....

 

[archie_MN]

When you can't even see the old sealer, percarb/oxalic will usually do the trick. I'd bring some Hydroxide in case the cleaning reveals spots. For redwood I thin out my Ready Seal with about 1 gal of mineral spirits to a 5 gallon jug. Dark is a good plan, RS dark brown looks great on redwood. Plan on at least a half hour between floor coats if you're going to offer a transferrable warranty on the sealer.

On redwood in particular it can be hard to see old sealers, even once SH has been applied. The good news is it rinses much faster than cedar or pine.

As for general wood cleaing chems..I use percarb for unsealed wood or previous customers with RS. For anything else I carry 2 different concentrations of Hydroxide, if the thin stuff wont cut it downstreaming, I shurflo the stronger mix. Remember the stronger the SH, the more oxalic. Also, I carry 12.5% bleach for mold. I use the bleach maybe 5% of the time.

 

[GumDestroyer]

Great advice Jake. I think to "let the chems do the work" is probably a better idea than the pressure washer doing the work. lol

 

[archie_MN]

Great advice Jake. I think to "let the chems do the work" is probably a better idea than the pressure washer doing the work. lol

Thanks, hope it helps!

I hear ya about the chems, but a 4% SH mix downstreamed is alot easier on the landscape than a 12% straight. Old wood is going to take some washing, no matter what chems you're working with.

 

[GumDestroyer]

Found my camera! Here is the existing redwood deck.

 

[Gogreenwash]

Finally got camera back from the big man.

By the looks of them pics it's going to be a fun job hope u land it and make it look pertie again.

 

[archie_MN]

Looks like an easy cleanin, good time. Good luck! Post up some after pics for us.

 

[GumDestroyer]

Thanks guys. Job sold. Will do on posting picks. Also...a great neighborhood for high exposure!

 

[Calob]

its going to be such a night and day diff when your done. cant wait to see your after pics. decks are definitley something i want to get a good hand at.

 

[GumDestroyer]

Jake,

I order some sodium percarbonate. I already have 50lbs of oxalic for neutralizing and whitening.

 

[GumDestroyer]

I wonder about sodium percarbonate for paint removal too or best just use on stains?

 

[PressurePros]

Downstream a sodium hydroxide based stripper, follow with downstreamed acid and you will be in and out of there.

 

[GumDestroyer]

That's interesting? What about overspray? Isn't a pump a little safer? So you don't recommend sodium percarbonate Ken followed up with oxalic to neutralize?

 

[archie_MN]

I'd go with Ken on this 1, just because you don't see the old sealer doesn't mean you won't hit it. If you don't have SH or don't want to buy a bag for 1 deck, hit it with the percarb. From your pics, I'd give you 80%+ that percarb will do the trick.

A little about percarb. I don't know much about "percarb based" cleaners, since I buy raw chems, but I only use percarb on unfinished wood and previos customers with Ready Seal. I tried percarb once on a painted fence. It was great at loosening up flaking chips, but it did nothing for removal. I honestly haven't perfected painted decks, I have an awesome painter I kick em to.

I almost always mx and downstream percarb on site. Can't be used in a pump-up sprayer because it's expanding.

As for overspray...prewet the house and yard and rinse immediately after chem application for both chems. For oxalic, rinse any metal (especially shiny metal) very well. (I don't mean to call you new, just figure it's better to know)

 

[PressurePros]

That's interesting? What about overspray? Isn't a pump a little safer? So you don't recommend sodium percarbonate Ken followed up with oxalic to neutralize?

A quick prewet as Jake mentioned and you'll have no problems. The only thing to watch out for is oxidized aluminum. Even then, downstream strength shouldn't be an issue. As soon as your are done DS'ing, re-rinse plants, siding and windows. Be careful not to over dilute the floor mix. Sodium percarb I abandoned a few years ago. Too slow.

 

[GumDestroyer]

Excellent advice. I purchased a 30lb bag of raw percarb so Ill downstream it and wait a bit then follow up with oxalic, rinse at low pressure and see what's up!

 

[PressurePros]

Percarb has to be put on straight most times. That's one of the main reasons I don't mess with it anymore.

 

[archie_MN]

Percarb has to be put on straight most times. That's one of the main reasons I don't mess with it anymore.

I mix percarb a little strong and either DS or Xjet it. Never had an issue with it not working fast enough. On a deck where I'm going to use percarb, I love inviting the HO to watch me clean. I like to turn customrers into company cheerleaders by showing them the percarb process in particular.

FYI: After it fizzes out, percarb leaves behind water, hodrogen peroxide and sodium carbonate (water softener salt). Nothing else.