BAC50 dilution for fencing?

[Moor]

I’m looking using some BAC 50 to remove green algae in some fencing, it’s not something I have used before though. From what I have read 20:1 looks to be the right dilution, can anyone confirm?

 

[Pjj]

I believe that’s the strongest solution some recommend up to 50-1 if it’s just green algae 20-1 is stronger than you need really @kevinc250 is the man for this

 

[Moor]

I believe that’s the strongest solution some recommend up to 50-1 if it’s just green algae 20-1 is stronger than you need really @kevinc250 is the man for this

Thanks Pjj, hopefully Kevin will add his advice.
Is there anything out there that will restore weathered grey fencing too?

 

[Pjj]

Thanks Pjj, hopefully Kevin will add his advice.
Is there anything out there that will restore weathered grey fencing too?

I think oxalic acid will revitalise it but again @kevinc250 is your man on this type of thing

 

[kevinc250]

hi @Moor, thanks for the tag paul, first things first bac and ddac (both similar substances) work better if you add say, ro water if you are in a hard to very hard water region the ph of the water will make the biocide less effective so, to re-cap ro water for biocides like bacs and ddac and hard water ie tap for hypo, it goes without saying that, on no account should any of the above be mixed together.
the correct dilution rate is really more of an eu directive thing to stop people like us and, many more trades using neat chemicals as and when they feel like it.
the 20-1 ratio is just fine and does the job for fence panels and gates etc, what you'll first see is the green alghi losing colour at first ie going dark then, the green goes a few shades lighter as the colour bleeds out thats, when you know its done its job.
keep this phrase in mind "as the ddac or bacs soaks into the wood it is acting as a wood preservative" as should kill off most future attacks of alghi.
if you think of this in a different way and, this is how it was explained to me is imagine, two armies both of lets say a thousand solders each ie bac50 and green alghi the bac or ddac is a kamikazi kind of guy when they go into battle they each kill one another then the end result is no solders left- the alghi has gone and so has the bacs.
hence you use no more than is needed and if you apply a little bit more it would help in the future when the green alghi comes back- think kamikazi so you can get your head around it.
grey or silvered looking wood is usually a sign of having bacs or ddac applied at some point that is the downside but products like owatrol can bring the natural colour back or if you go the american route blast it with sodium hydroxide and then re blast with oxallic oxide a natural wood bleach.
hope this helps to try and understand how it works

 

[Iron Giant]

I thought wood particularly fencing goes silver over time when no preservatives have been applied, the fence out the front of our house has gone a bit silver and it has never been touched with anything, I need to treat this year with something to get rid of the green that has started to appear over the winter months.

Ideally trying to find a product that won't cost the earth and that I can use on the fencing without bleaching the tarmac footpath and something I can use to kill algae growth on the concrete window sills all around our house so they can have their first lick of paint in 87 years and to treat our block paving periodically

 

[kevinc250]

it occurred to me this morning, you know around 2am that i actually gave the wrong information on dilution, sorry about that, try a 40-1 solution not 20-1 ie 500mm to a backpack is as good a gauge and is there or there abouts .

 

[Moor]

Thanks Kevin, a great explanation there. I will go with a 40:1 dilution.
I have seen several videos, mainly in USA showing hypo being sprayed in fences and it brings the colour back immediately. It’s quite an expensive fence (it’s mine) that’s not had any treatment before but I don’t want to potentially ruin it with hypo as I have read it’s not good for wood.
I will look into owatrol

 

[kevinc250]

Thanks Kevin, a great explanation there. I will go with a 40:1 dilution.
I have seen several videos, mainly in USA showing hypo being sprayed in fences and it brings the colour back immediately. It’s quite an expensive fence (it’s mine) that’s not had any treatment before but I don’t want to potentially ruin it with hypo as I have read it’s not good for wood.
I will look into owatrol

what you will have seen is most likely sodium hydroxide being sprayed-even the yanks choose that over hypo for fences hypo will damage the wood over time mate,
hypo breaks down the lignin in wood, the substance that holds wood together think of it as the wood glue dissolving if you use hypo so you can get your head around it.
owatrol is going the rounds on social media and to be honest the results i have seen are very good-ones i'd be happy with if it were my fence, its horses for courses really and what would you want to see as in the end result? nice white and clean looking then hypo, a clean but may go a bit silvery looking over time then biocide ie bac or ddac, somewhere in-between these is the benz which is more sodium hydroxide than hypo so could give you the result you have seen on you tube pretty much there and then without causing damage to the lignin.

 

[Moor]

Thanks again Kevin. Im looking to remove the green patches (it’s not a lot) and restore the wood colour to the fence before oiling it.
I had a look at Owatrol, I can’t see what the active ingredients, it mentions it’s suitable for rust too, is it not oxalic acid?

 

[kevinc250]

if its suitable for rust then, i would say that it has oxallic acid in it @Moor .
i don't know how much fencing you have and yes i know how expensive fences are i would, if it were my own use benz lightning on the fence and then owatrol to give a perfect base to apply oil to the wood, it may cost a bit in the initial term but in the long run that fence will look great for longer.
using both of these should give you the results you see on you tube with the yanks,