I would prewet that first, then percarbonate with 15 minutes dwell time- light scrubbing then rinse off and see how it looks when dry. Go from there. Small test area of course.
No acid wash after? Donāt you need to neutralize?
@WashTheLZ my comment was only for a test spot and see how it cleans up. If good- then naturally neutralize wood and rinse well.
Does it have prior stain on it? Looks like it may. If it does, may need to use a stripper.
with cedar you can pressure wash up to about 900-1000 psi instead of scrubbing.
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Ok yea I never use percarbonate. Didnāt know if itās different.
Yes. Stained. I think metasilicate might be enough. Or do you think hydroxide?
If your intent is to stripe this and just not clean, I would find out if they used a water or oil based stain on it.
Iād bet a shiny new penny that is water based. All the old failed water based I see looks identical.
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The intent is clean and strip then stain if they want us to do it. Conversation hasnāt been had.
Looks like half logs and not siding, because siding normally overlaps. Iām not there and I canāt tell based on the pics. I will answer with an idea that it is half logs.
You can do a test spot with a small brass brush. Lightly apply to wood in an inconspicuous area. If the wood bares then you know you are stripping. Get HO permission for every test. I test with HW mix, SP, and an Osborn brush. They are told that the osborn brush will stirp wood bare.
The osborn brush is used in the log cabin industry for buffing/polishing logs. The log cabin industry uses a lot of sandblasting and grinding, but some use chems. Wood is wood, and this doesnāt have chinking. But even with half log homes you should be backer rodding and caulking the checks. Donāt use junk caulk, get the good caulk meant for log homes. Then you will have to tape around the checks before caulking or the caulk will go into the wood and you will have a smeary mess around every check instead of clean lines. No bubbles in your caulk, apply consistent steady presure. Putty knife the caulk, peel the tape, perfect check seal with elasticity.
Last thing, and this is real important and a lesson I learned the hard wayā¦ALL LOG HOMES LEAK, someone has to be inside the home if you spray it with water. The builders will leave gaps around windows/doors, sometimes the painters (which are also the builders sometiems) didnāt even bother caulking the windows/doors.
If you strip, unless it is a small one side job, plan on being there for a week. You have to remove furring on log homes otherwise it will look like crap. Oh, and get a lift or stages/ladders. When a check runs down a log it would be tough to do on a ladder. Charge accordingly, no one is doing it on the cheap in my area unless they are hacks that donāt know what they are doing.
Not a deck, but Iām happy with the results, still a few spots of green here and there and some really heavy spotting in areas, but overall not bad and the homeowner was ecstatic. House wash mix, dwell for about 10 minutes, green tip at 1500 psi (figured I needed a little more pressure for the thick stuff), oxalic, dwell, and a heavy rinse.
Bonusā¦ little helper stopped by.
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Looks good and a relatively economical solution
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Looking for some advice regarding left over chemical residue.
After I clean wood it seems like thereās always white residue left behind in the wood, specifically on the nuts of the wood. Iād like to avoid that in the future because most of my projects involve staining the boards at the end and itās takes a long time to sand down an entire deck. You can we the colour difference through the stain. Iāve attached a photo of the issue below
I have been letting metasilicate sit for 10 minutes, rinse with a 25/12 nozzle on my udor 30/24s. Sometimes use a 40/15 nozzle. I like the 25 better. I then follow up with oxalic and let it sit for about ten minutes before rinsing that off. I usually rinse the oxalic off with my M5.
I think I am probably not rinsing enough after the metasilicate, but I donāt want to have to go over every board twice. I have also seen a lot of people say the leave the oxalic on without rinsing at all, which makes me think the oxalic isnāt the problem.
Also attached a couple photos of some recent projects.
Processing: IMG20240704131833.jpgā¦
Couple of questions - are you letting the metasilicate sit too long or letting it dry or mixing it too strong? That wood looks like itās been bleached out. Iāve never used the stuff, so donāt know how it reacts. Maybe try doing smaller areas at a time. Sure someone who uses it regularly will jump in here soon @DisplacedTexan
I use metasilicate. We do a cup per gallon and it never comes out that bleached even after an ox wash same amount of mixture per gallon. We also donāt have a fur problem like that either. Which could be a too much pressure on the wood problem. We have the same dwell time as you pretty much but we also donāt let it dry until we walk away from job
Also I could be wrong but I think if you leaving oxalic on itāll not be good. Rinse everything a lot. We are almost flooding every yard when we do decks. Have you done many other jobs with meta or are these it.
What type of mix are you using with the SM?
I typically donāt let SM dwell for more than a minute or so. Once it turns the wood black, itās pretty much ready to be rinsed. You also have to work in smaller sections with the SM so you donāt get behind on rinsing.
For example, in the picture below, I would treat the vertical boards first and by the time Iām done applying the SM I would immediately start rinsing at about 800psi. Then do the steps and so on and so forth. Just work small sections.
Also, I have gotten into the habit of pre-wetting any wood before washing. Seems to help.
One thing to remember is that wood furs. Thereās really no getting around that. You can do your absolute best to limit the furring (and you should) but if youāre going to be staining afterwards then 90% of the time that means youāll be sanding anyhow so donāt get too caught up with the furring.
Renting floor sanders is CHEAP. Donāt be afraid to spend a little money to make life easier.
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Iv never heard anyone rinsing the SM that fast!! We may try that next time. Do you agitate the wood at all? Like a nice deck scrub?
It all depends on the condition of the wood. If itās really, really neglected then you may have to let it dwell longer but most of the stuff I work with is in relatively decent shape. The only time Iām scrubbing anything is if thereās dirt buildup, lichens or anything sitting on top of the wood.
The deck posted above looks to be in pretty nice shape. Usually the steps are the first thing to show signs of neglect and those look fine. In my opinion, SM wouldnāt even be what this one really needed. Iād be surprised if it didnāt clean up just fine with just down streaming from a 4 or 5.5gpm with one of the Gold Standard injectors. Sometimes thatās my preferred way since I can let it dwell a bit longer and work at a slower pace. Just have to do an OA post and rinse the snot out of it.
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