Did you get those dry/after pictures?
I remembered to take the picture but forgot to post. Thanks for reminding me.
This one doesn’t look as light as the other one I posted above. I’m sure it just depends age, location, how much sun it gets, etc so probably never really know which ones will lighten up too much.
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Man looks good bet the customer was happy.
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Wow, that deck looks great! I’m surfing all these deck cleaning threads looking for 1 missing piece of info. Hoping someone can fill me in on it. So, it seem to me like people are DS oxalic and SH mixed together, let it dwell then rinse it off? Or apply SH, rinse it off, then apply the oxalic? Do you let that dry or do you rinse that off also? If I am way off, please let me know 
I have been washing houses and am finding a ton of nasty decks. Wouldn’t mind add that service.
DON’T mix SH and oxalic acid ever! You will create a toxic gas and will really hurt yourself and anyone else around. You put down SH first, wash the deck with medium pressure, then apply oxalic. Let the oxalic sit for a few minutes then rinse it off without pressure.
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I had no idea those 2 would have such a reaction! Thanks for the info! Im glad I asked before experimenting on my own.
Don’t let the sh sit too long or mix it too strong. You’ll fur the wood and then you’ll have to sand it. I usually let it dwell for about 5-10 minutes. Don’t let it dry either. Same goes for the oxalic. Keep misting to keep it wet. I usually apply both with a pump sprayer but I sometimes go stronger than what I can ds. Rinse the oxalic really well.
If you’re concerned with the wood furring you can use sodium percarbonate. It’s a safer and more mild option.
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Ok, so I can us sodium percarbonate in place of the SH. I bought the sample pack of chems from Pressure Tek when I first started. I have only used the Elemonator (I love that stuff) and have a jug of the F-10. Im assuming its the same process. Apply F-10, rinse, apply F-8, rinse.
Yep…I’d probably let the percarb dwell for like 15 minutes. Keep misting to keep wet. I’ve noticed that if there’s a bunch of algae you might need to hit it with a deck brush too. You might be able to just reapply a couple of times instead of brushing. Mix at 8 oz per gallon. Same for oxalic.
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If the deck is really covered in moss and mildew, should I still use SH? If so, do I just use my normal house wash mix? While washing houses, I alway keep the decks pretty wet to help dilute the HW mix but it still cleans the first 2 feet of the deck no matter how hard I try to rinse it off right away. Would that mean that my HW mix is to strong to be used on decks? I washed a house last week where the deck was so bad, I actually slipped and fell on it. I wanted to spray it down with my HW mix but wasn’t sure how it would negatively affect the unfinished wood.
What’s your mix and how are you applying it?
Straight 12.5% SH and a splash of Elemonator down streamed 10:1.
Have you ever tried ds a weaker mix? You might be going through more sh than needed. I also use a 10:1 injector but I mix 2 gallons of 12.5% sh with 3 gallons of water and then down stream that. I tested my draw rate and that puts me right around 1% hitting the house. That’s strong enough to clean algae from siding. Some even aim for like .8%. I might bump it up every now and then for a real dirty house or colder weather but is not normally needed. You might not get the same draw rate as me. Part of it depends on your pump, rpm of engine, length of hose, etc. It’s not something you really have to know. If it’s not killing algae add more sh. If it kills it in a few minutes add more water. It might be handy to figure it out for wood though.
I doubt your hw mix is strong enough to fur the wood unless you leave it on there too long or let it dry. Let it sit for 10 minutes, rinse away, and see what it looks like. If the algae is real bad you might need to bump it up some or do it a couple times. I wouldn’t use more than around 2% @anon37135677 though. (There…that’s more exciting than just saying “around 2% max though”.)
If you plan on getting into wood more maybe get an old fence panel or deck board and experiment. You might be able to charge a little more by offering brightening/neutralizing too. I usually just include it as part of the estimate but I like the results and customers do too. If they plan on staining it afterwards I would definitely neutralize the sh.
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I’m assuming I need to see how long it takes to draw out 1 gallon of water and divide that by however many gallons of water I used (4gpm pump). I’ll do that today. It would be nice to see exactly what percentage of SH I’m applying. My very first house I was using 10% and it wasn’t strong enough if I cut it with water so I didn’t the same thing with the 12.5%. I wouldn’t mind saving some money I’m calling around to a bunch of people I know to see who has an old fence or deck they don’t mind me experimenting on. I REALLY appreciate this info! The people on this forum have taught me more than I ever thought I would know, and I still have a TON of questions!
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You’ll learn so much from this forum. Pretty much everything you can think of and more can be found with a simple search. Don’t know where I’d be without it.
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Fhp, how far away is your gun when rinsing with the 4020? About one board with, or further?
So, I checked my DS ratio today before I washed my father-in-law’s house for Father’s Day. He had some pretty bad mold around his pool house and all the bushes that line his house.
Let me know if my calculations are incorrect. It took 11:25 minutes to downstream 1 gallon of water. Since I have a 4gpm pump, that means I used 46 gallons of water. Thats a ratio of 46:1. Since I am using straight 12.5% SH, that would give me a downstream ratio of 2.7%. If that is correct. I should cut my bleach with water by 50% and see how that goes. The mold on this pool house took 2 applications to completely remove it all. My father-in-law also has never had his house washed and the pool house has been there for about 15 years. So that mold had really taken hold.
Well, you need to measure how much water is going through your pump too. Just because it is a 4gpm pump doesn’t mean it’s really pushing 4gpm. It could be more or less but otherwise you got it.
Another way to approach it is cut the SH in half and see how it works. Maybe cut it in half again and check the difference. 
Your math is way off . You forgot to multiply by the bleach strength, it’s not 100%, it’s 12.5%.
0.125 bleach / 46 = .002. or 0.2% effective bleach on the surface. Your need to be at 1%. So your mix 5x too weak.
You have the wrong injector, or wrong settings.
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