# Cedar decking, brightener after sanding?



## Jmayspaint (Mar 26, 2013)

I've got a new 1,200 sqft cedar deck floor to do. Some dufus bleached and power washed it and really screwed it up. This is probably the worst bleach burn I've ever seen. 

Sanding it down now in prep for SRD, and I'm starting to think it may be a good idea to do a brightening step afterwords. Seems like it would help even out the sanding marks, and just help with the look of the finished product overall. 

I can't remember ever having done brightening after sanding, and even though it seems like a good idea to me In this case, I wondered if anyone else has done it, or has any thoughts on how it would do or if I'm missing anything in my thought process. 










It's weird, In places, you can see footprints in the damaged fibers. Like they walked on it while the chems were tearing the wood fibers all to he!l. 










Another thing I'm worried about is the edges of the boards,









This is a huge deck and I would hate to see discolored lines at the cracks after staining. I also cringe at the thought of having to sand all those cracks. 

Any chance a brightening step would help hide the white looking, damaged wood in the cracks? Perhaps with a scrub added? I can live with the fuzzed wood in the cracks, as it's fairly isolated. But they all have that white look of bleach burn. Wishful thinking to hope Ox acid would help with that? 

I wish I didn't have this to do at all, but it's a good customer.

Thanks for any thoughts.


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## Seth The Painter (Jun 24, 2015)

Does a bear shyt in the woods? Hell yeah I would put brightner all over that. Use a quality brightner this is going to help you tremendously.


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## ReNt A PaInTeR (Dec 28, 2008)

Use this one F-8 Neutralizer / Brightener


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## stelzerpaintinginc. (May 9, 2012)

If this were my job, I'd stop the sanding now and wash first. By the looks of it, the deck was never thoroughly rinsed. Either a Percarb followed by citric or oxalic, or a weak Hydrox downstreamed, followed by acid rinse. 

The reason for washing first to remove as much as possible is due to the fact that sometimes heavy sanding can almost leave a sort of, "mill glaze" of its own, (especially cedar), which will prevent maximum penetration of your stain.

After the washing, you could then only sand as needed.


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## Jmayspaint (Mar 26, 2013)

ReNt A PaInTeR said:


> Use this one F-8 Neutralizer / Brightener



That looks like a good one. 10 lbs of powder for less than $40. I've been paying almost $20 for the BM brightener liquid concentrate.


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## Jmayspaint (Mar 26, 2013)

stelzerpaintinginc. said:


> If this were my job, I'd stop the sanding now and wash first. By the looks of it, the deck was never thoroughly rinsed. Either a Percarb followed by citric or oxalic, or a weak Hydrox downstreamed, followed by acid rinse.
> 
> The reason for washing first to remove as much as possible is due to the fact that sometimes heavy sanding can almost leave a sort of, "mill glaze" of its own, (especially cedar), which will prevent maximum penetration of your stain.
> 
> After the washing, you could then only sand as needed.



Stopping the sanding now would be heavenly, it's about half done. It's taking so much longer than normal prep sanding because of having to remove so much damaged wood. 

I used to use washing to remove layers of substrate. Plenty of times I've hard washed a deck or siding or whatever to remove a layer or two of wood, then sanded the fuzz off. I thought it was easier than sanding alone when the goal was to take off multiple layers. With all the hype in recent years about "injecting water" and the other hazards of hard washing, I've quit doing it. 

I'm still not convinced there is anything necessarily wrong with removing loose substrate with water pressure rather than mechanical means provided there aren't hazardous materials considerations, and containment is feasible. But we've been trying the soft wash approach lately. 

I wonder if one reason the deck may have been under rinsed is its close to a pool. 










Maybe the wash guy was being too skittish with the rinse water around the pool. 


Good point about the potential for sanding to "polish" the wood. I'm thinking that's another benefit of an acid wash after, to counter that possibility.


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## stelzerpaintinginc. (May 9, 2012)

Jmayspaint said:


> Stopping the sanding now would be heavenly, it's about half done. It's taking so much longer than normal prep sanding because of having to remove so much damaged wood.
> 
> I used to use washing to remove layers of substrate. Plenty of times I've hard washed a deck or siding or whatever to remove a layer or two of wood, then sanded the fuzz off. I thought it was easier than sanding alone when the goal was to take off multiple layers. With all the hype in recent years about "injecting water" and the other hazards of hard washing, I've quit doing it.
> 
> ...


My guess is the pH of that deck even after a thorough sanding will probably be around 12, so some kind of acid would be best to bring it back down to neutral. Given those pics and your particular situation, Citric Acid might be a better choice than oxalic


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## Hines Painting (Jun 22, 2013)

You sure that's just not a really bad whitewash or gray semi-trans? I've never seen bleach leave any wood that bad. 

Unless they put a ton of straight bleach on and that is the remaining salt crystals ground into the surface.


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## Damon T (Nov 22, 2008)

Jmayspaint said:


> Stopping the sanding now would be heavenly, it's about half done. It's taking so much longer than normal prep sanding because of having to remove so much damaged wood.
> 
> I used to use washing to remove layers of substrate. Plenty of times I've hard washed a deck or siding or whatever to remove a layer or two of wood, then sanded the fuzz off. I thought it was easier than sanding alone when the goal was to take off multiple layers. With all the hype in recent years about "injecting water" and the other hazards of hard washing, I've quit doing it.
> 
> ...



What size sander are you using and what size boards are they?
I've got a big deck to sand after big wash last week. One of the most neglected decks I've seen in a long time. I probably shouldn't have taken the job but too late now! Am probably going to rent a floor vibrating sander instead of doing the big areas by hand held sander. Still was thinking of getting a CT26 and RO150 to add to my collection.


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## PRC (Aug 28, 2014)

Damon T said:


> What size sander are you using and what size boards are they?
> I've got a big deck to sand after big wash last week. One of the most neglected decks I've seen in a long time. I probably shouldn't have taken the job but too late now! Am probably going to rent a floor vibrating sander instead of doing the big areas by hand held sander. Still was thinking of getting a CT26 and RO150 to add to my collection.


We did a large, severly weathered cedar deck last year and we started with 40 grit on ro125 and ro150. What really picked up the pace was getting the ras115 out of the truck. Put 50 on it and one pass, followed with 80 on the ro's and done.


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## Jmayspaint (Mar 26, 2013)

Thanks guys, I'm pretty convinced to go ahead with a brightener after the sanding is done. They're regular 6" boards and were using mostly 5" sanders. I did consider using a big vibrator, but several of the boards are cupped. Might still have helped. At this point, I guess we will just slug on through it. 

Not today though, have to pull off to do a small interior, think it's going to rain anyway. 

One thing I like about the BM brightener is that it's a blend of citric and oxalic acid. Seems to work a little better than some other concentrated liquids I've tried. Though it does seem a powder concentrate is the way to go overall. Think I'll order a box to have on hand. The BM brightener, or any brightener really, is another thing that's not real easy to get in the area I work in now. 

I've never seen bleach burn that bad either, at least on that large of a scale. It's a new deck, wasn't even there 6 months ago when I was last at this house. I'm not sure why they (builder) thought it was necessary to bleach it. I'm suspicious that maybe they installed boards that had already mildewed. Doesn't make sense otherwise, as a 6 month old deck in full sun like this one is shouldn't have any mildew. 

I think the severity of the damage is from a combination of too strong a chem mix, inadequate rinsing, and prolonged sun exposure. 

Good point about the PH. If it's burned that bad, it's likely to be out of whack. Another reason to brighten. 

Supposed to be getting away from doing decks, but this is the second one I've got roped into doing this year :cursing:


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## PACman (Oct 24, 2014)

stelzerpaintinginc. said:


> If this were my job, I'd stop the sanding now and wash first. By the looks of it, the deck was never thoroughly rinsed. Either a Percarb followed by citric or oxalic, or a weak Hydrox downstreamed, followed by acid rinse.
> 
> The reason for washing first to remove as much as possible is due to the fact that sometimes heavy sanding can almost leave a sort of, "mill glaze" of its own, (especially cedar), which will prevent maximum penetration of your stain.
> 
> After the washing, you could then only sand as needed.


It isn't called mill glaze anymore. It's called "kumquat".


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## PACman (Oct 24, 2014)

stelzerpaintinginc. said:


> My guess is the pH of that deck even after a thorough sanding will probably be around 12, so some kind of acid would be best to bring it back down to neutral. Given those pics and your particular situation, Citric Acid might be a better choice than oxalic


Or a brightener with a blend of the two. Like Cali's brightener.


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## Jmayspaint (Mar 26, 2013)

PACman said:


> It isn't called mill glaze anymore. It's called "kumquat".



No, it's called your imaginary friend
:jester:


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## PressurePros (May 6, 2007)

You don't need a brightener. Try a percarb cleaner and even pressure (800 psi at the nozzle.. six inches off surface) to wash it. 

It looks like a finish to me as well. but if it's grayed wood, the best bet is to use a more base cleaner as opposed to acid and wash it well to remove the grayed fibers. A percarb will also remove any dirt/mold left that you may not see.


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## radio11 (Aug 14, 2015)

PressurePros said:


> You don't need a brightener. Try a percarb cleaner and even pressure (800 psi at the nozzle.. six inches off surface) to wash it.
> 
> It looks like a finish to me as well. but if it's grayed wood, the best bet is to use a more base cleaner as opposed to acid and wash it well to remove the grayed fibers. A percarb will also remove any dirt/mold left that you may not see.



Looks like a gray color solid stain to me. You've got it looking a whole lot better now, but sanding may not have been necessary. I think I would complete the sanding now, but try washing (as mentioned by Ken) for the cracks/edges. 


Sent from my iPhone using Tapatalk


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## Jmayspaint (Mar 26, 2013)

radio11 said:


> Looks like a gray color solid stain to me.
> 
> Sent from my iPhone using Tapatalk



Pictures can be deceiving I guess. I assure you guys there is nothing on the wood except a few layers of extremely damaged fibers. I guess it looks grey in the pics because of the bleach burn. In person, it's more white looking. 









I'm not familiar enough with pre carbonate wash chemicals to feel comfortable going that direction on this one. I wish I was, could have maybe saved a lot of sanding.


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## PACman (Oct 24, 2014)

I'm curious as to what wood it is. Is it treated? It looks a lot different then the treated wood they use around here. There is of course a large variation of wood types and treatments used around the country. The wood used here wouldn't have be as knotty as that also.

I wonder if this could be some of the silicone impregnated wood I was asking about a few months ago. The look of that white doesn't look like anything I have run into before. As uniform as it was it would almost have to be a reaction with something that was applied to it, or it was supposed to do what it did naturally.

How old is the wood and is it doing the same thing in shaded areas?


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## Jmayspaint (Mar 26, 2013)

It's untreated Cedar. It's a new deck, only been down a month or so. 

The shaded areas are not chemically burned. The majority of the deck is in full sun for most of the day (pool area) except for the covered section. 

The whole deck got bleached and washed, but only the sunny areas were burned. That's unfortunately most of the 1,200 sqft area. I'm thinking the combination of bleach, hot sun, and under rinsing caused the severe burn. The shaded area was spared. 

Here's a pic of the shaded area. You can kinda see where we stopped sanding. Don't think I'll have to sand that area, or if so lightly.


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## PressurePros (May 6, 2007)

Its the tannins in the wood. Go ahead and use an acidic cleaner to break it down. 

Be careful which product you use. Many stain manufacturers have specific semi trans stains for cedar, redwood or other woods prone to extractive tannin bleed. 

The tannins came to the surface because you washed it. Nothing wrong on your part, it is just what can happen with new cedar.


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