High Pressure Water Washers

[PCH]

Hey guys,

I dare say some of you guys have played with various models of these, brands such as Karcher and Gerni are common enough.

Firstly, I have a Gerni model costing a bit over 300 from Bunnings and capable of about 2000psi. I knew before I bought it that professional petrol engine powered devices capable of 3000psi+ are really what's needed for cleaning all the crap off your driveway, but those are almost 200 bucks a day to hire.

Long story short, I bought this understanding it's limitations. So far I'm pretty impressed with it's performance, having just blasted 20 years worth of moss and other crap off a section of the yard.

I used a neutral pH detergent, and although on balance I'm pretty happy as I said, there is still some staining from the moss or weather or whatever where water has collected in puddles over the years.

Does anyone have any thoughts on how I might get rid of these stains? They aren't oil based, it is just exposure to the elements that has caused this.

It may actually not be surface grime that can be blasted off. It might have somehow stained the brick pavers to a depth of a few mm's or so - can't tell.

If I don't get any tips here, I'll just let it dry and repeat the procedure and be happy with that.

Ok dudes, all polite suggestions welcome :)

[raymo]

If you pour some bleach from under the kitchen sink onto the stains ,
and leave for a while, and then have another blast, that might do the trick. The higher pressure units, from 3,000-5,000 won't remove stains
much better than yours; used slowly, they take a fine layer off the concrete.
raymo

[PCH]

Hey Ray,

Thanks for the tip re the bleach - I'll try that and see how it goes and report back soon :)

Cheers buddy

[GrahamL]

these things work great on concrete ,, dont know if the smaller machines will run them though ,for referance through work we bought a few karcher smaller units and sure didn't use them much before they died,absoloutly no joy in warenty support .

http://www.ebay.com.au/itm/like/171341785042?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=107

[multiweb]

I've had a Karcher 5.55 Jubilee for over 5 yrs. Just changed the pump today. Normal wear. Pretty happy with it. Have used it a lot. The attachment I use for concrete is like a mower. Bit like the eBay stuff but more robust. On the topic of concrete once you have pressure washed it what's a good sealer? UV protect/Durable :question: I have used a variety over the years but they all end up pealing. Including Feast & Watson.

[LewisM]

BEst thing to clean concrete is oxalic acid. Works well - can be bought at any hardware store as crystals, which you dissolve in water.

I have had a Karcher for 10+ years, Replaced the main capacitor once, and the hose once, and no other issues. Blasts crap off driveways easily - it's got some testicular grunt :) I stupidly used it on a mates car one - good bye silver trim... and some other paint :(

[multiweb]

Mine is stamped and tinted so I don't want to scrap the hell out of it but I'm after a good sealer to make it shinny and silky smooth afterwards. :cool: Ideally the indian minas craps should slide along the slope back in the grass. :D

[RB]

I'm sure you would've had some spare Takahashi green to fix it up again.

:P

[beren]

I have a karcher that works at 3000psi, I tried my best with my paving area but even with this machine I couldn't get a result that I was happy with. Ended up getting a business that deals with cleaning and sealing, came up a treat and much easier now maintaining the finish. If you get someone in get a few quotes some crazy price differences out there.
Oh don't get complacent with these water blasters, saw a nasty incident with a workmate out on a remote workplace where he accidently sprayed his wrist and sustained a fluid injection injury and got a trip back to Perth via the flying doctor.