algae on deck

[LITTLE GUYS 14]

I did a deck cleaning (3 stories of dark stained decks) last friday. I went back today to see how it looked and almost got sick. The algae was still there pretty heavy. I used rpc 143 house helper (disodium percabonate) to clean the decks let dwell about 15 minutes. Can anyone tell what I might have done wrong or what I should use to get it off.

thanks dan

[PressurePros 248]

Sodium percarbonate is a slow mold killer. If it was heavy, you probably neded much moe dwell time. THe simplest solution is to go back and apply a 4% bleach solution and rinse it with a garden hose. (not what I advocate but it's what you will hear)

[LITTLE GUYS 14]

The owner has'nt called (yet) but I will go try it tomorrow. thanks

[plainpainter 217]

Try adding one cup of bleach to one gallon of water, and then add one cup of white distilled vinegar, put a little bit of a surfactant - maybe a few squirts of palmolive or something - and tell me how that works. Here is a link I found the other day talking about the effectiveness in bleach in acidic solutions. It's changing the ways I am thinking about my chems. It could also bring more people back to using bleach since you can use a lot less and get better results.

http://foodsafetyinfo.org/phpbb/viewtopic.php?t=1598

-Dan

[RPetry 564]

Dan,

Nice find. As far as I know, household bleach as in Clorox for clothes and other disenfectant purposes is a pH of 8. Look on the label and you will see sodium hydroxide (NaOH) added to the sodium hypoclorite to get the mix down to a pH of 8. From what I have read, this is the best pH for cleaning clothes, but do not have a clue if it applies to wood.

I, folowing others in this web site, have the idea that a conservative bleach mix is a good application for maintenance work on decks that have already been treated with a paraffinic oil stain. Is not as aggessive as a percarb solution and allows more of the oil present in the wood to stay in the wood.

Not sure about the vinegar, maybe someone else with experience will help out. I do know that a bit of soap as surfacant and as an aid to lift out dirt is a good practice.

Shane,

Another potential member of the BDA certified contractors.

[tropical wave 22]

I did a deck cleaning (3 stories of dark stained decks) last friday. I went back today to see how it looked and almost got sick. The algae was still there pretty heavy. I used rpc 143 house helper (disodium percabonate) to clean the decks let dwell about 15 minutes. Can anyone tell what I might have done wrong or what I should use to get it off.

thanks dan

Ill make it even easier. take a 5 gallon pail, put 4 gallons of water in it, dump 1 gallon of chlorine (pool chlorine, either 10% or 12%), a small squirt of dawn dishsoap........mix well, apply, dwell a little bit, rinse off.......

had a real nasty one last year (the pics may still be on here somewhere), stripper didnt touch it (made a mess is about it) and it laughed at the percarb....the above mix will remove it.... good luck :)

[VanDiesel99 14]

I'd like to hear more about adding vinegar to bleach to GREATLY increase its effectiveness. I figured when you added an acid to bleach it would neutralize its effectiveness. That website was very convincing but I would like to hear about some practical applications.

[LITTLE GUYS 14]

I will go out take a few pics and try some of these I will also try the vinegar mix. Thanks for the info

[CCPC 26]

That's really interesting. I wonder how that approach would work on roofs, or if it would possible to increase the bleach to water ratio just a bit before adding the vinigar for cleaning somthing like a roof. I can't wait to experiment with this.

[PLD 14]

That is certainly an interesting post, particulary as it would appear to fly in the face of basic chemistry. This link: http://www.chemistryquestion.com/English/Questions/ChemistryInDailyLife/3c_bleach_cleaner.html

Reinforces the statements concerning the effectiveness of low pH bleach, but also lists the recombinant equation for bleach and vinegar and HClO is NOT a resultant product.

This is definitely worth of further research. I personally don't think it'll pan out, but the ramifications are such that it's worth a try.

One last note, when we use bleach on a house, you're not consuming the mildew. You're just removing all color from it so it "disappears". Hence, a highly anti-microbial solution like that mentioned may very well just make dead, black, mildew.

[CCPC 26]

One last note, when we use bleach on a house, you're not consuming the mildew. You're just removing all color from it so it "disappears". Hence, a highly anti-microbial solution like that mentioned may very well just make dead, black, mildew.

I was thinking the same thing. There's quite a difference in killing microbials compared to bleaching and killing algea. The solution might kill just as effectively, or more so, but if it's dead and still on the roof, deck, etc that could be a problem. I'm still very interested in looking into it all the same.

[plainpainter 217]

vinegar contains ascetic acid, which is the main ingredient of Jomax, or as their advertisement says - bleach activator! Here are a couple of more links

http://www.apsnet.org/pd/PDFS/1997/0509-05R.PDF#search='ph%20range%20for%20bleach'

http://www.agnr.umd.edu/MCE/Publications/PDFs/FS715.pdf#search='Bleach%20and%20TSP%20not%20effective%20at%20killing%20spores'

http://department.caes.uga.edu/poultry/tips/09%201999%20P%20tip%20S%20M%20R.pdf#search='ph%20range%20for%20bleach'

The last link talks about how uneffective bleach is when used in conjunction with TSP - as found out in sanitizing a chicken plant. I don't know why my TSP/bleach has worked out fairly well. Or if I am fooled into thinking it's working.

-Dan

[CCPC 26]

The last link talks about how uneffective bleach is when used in conjunction with TSP - as found out in sanitizing a chicken plant. I don't know why my TSP/bleach has worked out fairly well. Or if I am fooled into thinking it's working.

-Dan

I think it's because they are talking sanitizing, where as what your doing is breaking down mildew and algea for removal. They seem to be different things.

[Richard 17]

I got 19% on my grade 11 chem exam 20 something years ago, but still somehow passed. Now I'm trying to learn from you guys. You are making my head explode.

I'm spending way to much on prepackaged cleaners.

Thanks for your input, and the time you spend writing. There is a wealth of info on these networks.

Richard Clayson

Revive Powerwashing Inc.

(905)802 0458

[LITTLE GUYS 14]

sorry it took so long to get back here. Anyway the bleach vinegar mix did't do much at all. the 6% in five gallons worked a little better and 12% house wash worked the best but still had to go over some spots again but the better the results the lighter the deck was getting. All were out of a pump up sprayer.

[Beth n Rod 1,279]

We would use HD-80 at about 3 oz to the gallon of water. Neutralize with Citralic. Never fails, no multiple trips or guesswork.

Beth

[clean kentucky 14]

rod and beth,

I was wondering if you use HD-80 diluted on a greyed out algae deck, than what do you use EFC-38 for? Maybe where there is a lot of blooming flowers? If I can jusgt use the HD-80 all the time instead of EFC-38 than I will because they both cost the same and I will use less of the HD-80. Right?

Doug Baker

Baker's Pressure Washing

270-268-1694

[Beth n Rod 1,279]

Ok...got my coffee...

When we first go to do a deck, never having done it, we use the HD-80 on it. Why? Because, even under the grey and algae and dirt, you can and often will find some sealer of some sort. We always go back to clean bare wood ( not a strong strip necessarily but we have found the SH solution works better) and neutralize with Citralic. Now in a couple years, when the deck is due a maintenance wash and re-coat, we will use the EFC-38 on it at a low measure to clean, but not to remove the finish that is on there. Then neutralize and reapply the sealer installed.

You will find you use less HD-80 this way, and really it does a great job. When we first started out in 1999 we used other things, and occasionally have tried new products, but we have always come back to HD-80 and Citralic. The results are consistent ( you do need to develop an eye for what is there and how much to use for how long) time and time again. We prefer to mix it per job and carry the powder. For one, we mix only what is needed at the strength we need it. Secondly, heaven forbid you spill, it is far easier to clean up a powder than a liquid.

Abandon the chlorine and vinegar and dawn stuff and use something that is tested tried and true that works and is formulated specifically for what you are doing. You will be glad you did when you don't have to go back, redo it, monkey around with mixing ingredients, etc...all the while the customer starts to wonder if you know what you are doing.

Hope this helps.

Beth :cup: :sunshine: :groovy2:

[Beth n Rod 1,279]

Also click this link http://forums.thegrimescene.com/faq.php?faq=new_faq_item and read the section on wood care.

Beth

[plainpainter 217]

Zinnser Jomax is based upon acetic acid with bleach along with a little bit of surfactant. And they have had tremendous success with that product. I am not sure about the mix, since I am a TSP/bleach man - which is alkaline as opposed to acidic. My shower stall for instance has been blooming lately with with what looks like red algae and mildew - and has been giving me tremendous foot itch. I have tried everything to clean it - even bleach, nothing has worked, sometimes it looks clean for a few days and bingo it's back. A week ago, I mixed some liquid laundry detergent into a quart spray bottle, with 1/4cup of bleach and a 1/4cup of white vinegar. And it was like setting off the nuclear bomb. It smells just like hospital bathrooms, and has gotten rid of the mildew and red algae or whatever growth, and is the cleanest I have ever seen any shower stall in my life!

Now I think this is the best anti-bacterial solution I have come across - as for cleaning homes and decks - who knows? Certainly TSP/bleach has an extremely stong peptizing ability for mildew, but Zinnser Jomax with it's acidic solution has a stong following.

Personally, I just mix a gallon of bleach with a cup of TSP/sodium-metasilicate into a 5 gallon bucket, along with 1/2 cup of Tergitol, fill the rest with water - and this solution cleans the heck out of greyed decks - and is a very strong stain stripper. Works great for those really old stains. Of course not anywhere as good as lye strippers like HD80.