Yes a 12 volt system isn’t enough pressure to remove stubborn stains. That’s why we use a pw to rinse with a soft spray tip. We also use booster pumps to rinse as well as apply.
Using a pw with low pressure tips is soft washing.
I’ve been doing house washing for four years (downstreaming) and using a rinse tip will 100% not remove 80% of mould. Won’t touch lichen, bird poo, insect eggs etc.
You could stand there all day with a rinse tip and the black mould on the gutters for example would still be there. Pressure is needed.
With a softwash, you’re basically hitting it with a high concentration of mix and bleaching. The following rinse would only remove light dust/dirt?
I just hit a shed with 3000psi to get the mould off. I still had to focus on many places to get the lichen off.
Need a bigger injector/hotter mix it absolutely will remove about all algae and mold from siding. A roof mix will also kill lichen sooo… get a new injector.
Here was some stubborn mould, after I hit it with the normal downstream solution (maybe 1%) hit it twice and it wasn’t cleaning up, so I mixed a 3% batch mix and used my 12v pump to apply, rinsed it off with low pressure nozzles, looked brand new.
@Jwind there’s no problem with my injector, it’s the best you can buy - according to @squidskc
Thanks for all the input. I can’t go any hotter than 2% on a house or barn though.
Again, the problem isn’t the mix. I can spray NEAT SH and surfactants onto the eaves of a house with insect eggs on and nothing but pressure will remove them.
It may work for you, all good.
For the record - I sprayed half that shed with 50/50 12.5 SH and the other half was a downstream mix.
Both applications vanished the mould, from a distance - but it’s still there. Low pressure removed the fluff. High pressure was needed to remove the rest.
That looks more like lichen than mould (especially the 1st pic), from things I read on another forum SH isn’t strong enough to remove the lichen I read that alkaline salts added to the mix, I don’t imagine it would be good for the grass or other organics in the area.
Here in Queensland with the humidity many of my house washes are annually, I don’t really see lichen but from roofs, TBH I find here with our roof surfaces/constructions that greatly differ from our neighbors in the USA, all roof cleans I do I use a rotary surface cleaner. Its just faster to give it a 2% pretreat then wizz it off lol.
Just soft washing tile or colorbond takes much longer and uses bulk amount of SH and multiple applications.
2% is as strong as the manufactures specify for colorbond.
You’re right. You’re not going to get embedded lichen off immediately with softwashing or downstreaming. You can kill it with softwashing and it’ll eventually disintegrate and fall off, but if you need immediate results, then yes, you’re going to have to use some pressure.