Me too, Im really curious about it. I havent messed with much lately.
Potash is potassium hydroxide which is similar to sodium hydroxide.
It really depends on the type of and condition of wood. You have to be careful with Sodium Hydroxide because it will fur pine quite easily.
If it’s going to be stained afterwards I like going with as mild of a product as possible. If it furs too bad it’ll need sanded or can stand out like a sore thumb when stained. If somebody doesn’t care about stain and just wants their deck cleaned I’ll go with something stronger.
It won’t take that long to pressure wash 100’ of fence. You’d be surprised on how fast it goes.
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Man, I’m getting several different opinions how to clean a darn fence.
Metasilicate
Percarbonate
Hypochlorite
Potash
Hydroxide
I can’t keep buying all this stuff only to discover it doesn’t work. I certainly can’t hand scrub 500 linear feet of wood fence, just need something I can 12v and 800psi rinse. Doubt I’ll make more than a couple hundred $$$ as she’s just “wanting my fence cleaned so I can stain it”.
Last year I xjetted my fence with SH and frankly it looked like garbage afterward. Oxalic wouldn’t have helped.
If metasilicate is the way to go then I’ll order some today.
There’s not one way to clean wood. Different variables come into play depending on wood, coating, how dirty it is, whether or not it’ll be stained, etc, etc, etc.
The only time I use Sodium Hydroxide is if I’m stripping old stain because I don’t like to risk furring. Although, regardless of what you use you’ll usually get a little bit of it.
When I use sodium percarbonate I usually do a quick scrub of the deck boards with a brush. I too wouldn’t do that to 100’ of fence. Depending on how dirty it is I’d probably just hit it with about a 2-3% sh mix, let dwell, and 1000 psi rinse. Top to bottom, next board, bottom to top, repeat. It’ll only take a couple of hours. I almost always use oxalic or citric afterwards to help brighten.
Heck, toss in 2 or 4 ounces of sodium hydroxide in your mix. You might be surprised.
How close to the boards are you getting with the 1000psi nozzle?
I’m not sure how SH doesn’t work for you? It works every time for me, I have all those chemicals at the shop and always grab the sh to do the fence and it comes out great with oxalic acid afterwards. It might be your technique. Check out what @Rammy1546 Posted few hours ago in the deck cleaning 101 thread, that’s basically the same method i use and Have never had a need to use any other chemical on wood. Wether it be a deck or a fence.
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I’m going to use my sprayer on my fence with ~3% SH and see what happens.
If just down streamed last time that was probably too weak to do anything. It might work on a fence that isn’t very dirty but you usually have to step it up to 2-3% for bad ones. Just watch your dwell times to prevent furring.
Ok here is a 3% SH, 15 min dwell and 1000 rinse.
I didn’t bother trying oxalic. Looks like garbage.
I may just tell her I don’t have the means to do her fence, there’s no way I would accept this.
How old is your SH? What strength are you starting with? How are you mixing 3%
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Mix 50/50 and spray it and see what it looks like if a roof mix still produces that then it’s definetly your SH
SH looses its strength over time. Your 12% can become 8 % real quick then 6, ect. So your “3%” could really be 1% or less than even. I’d go 50/50 in a sprayer as well with a little surfactant and wait 10-20 min and rinse.
It’s brand new 12.5 pool shock in gallon jugs. I measured on graduations on my sprayer, the mix may be closer to 5% to be honest.
There is a ton of organic growth junk on my fence as you can see, it’s possible her fence may be more like yours which is just grey.
I’m not quite sure what’s up with that, with a 5% mix that fence should be changing colour as soon as the SH hits it. Don’t give up on wood bud it’s most likely something minor, try it again on your next batch of sh.
@MDA1775 any suggestions? I’m curious.
Lol at this point I’m willing to hose down that top board with 12%.
Potash. Sodium hydroxide. Just saying.
Lye? Yeah I’ll get right on that.
