[davetherave]

I'm still very much a beginner to pressure washing cleaning so bear with me.

today i had to clean some flat concrete slabs of a patio and path and a little bit of crazy paving.

I tried using my whirlaway on them and it didn't work, i just got these like lines where it had taken some of the black/green gunge off but it didn't clean the whole surface. I couldn't figure out why it was doing it so i had to use my lance on the whole thing and it took ages. 

I was thinking the reason my whirlaway didn't work was coz maybe one of the two jets was blocked, it maybe had a bit of grit in it.

I've heard you are supposed to flush your equipment out before you start work to prevent grit getting lodged in your equipment but i'm not sure how you actually go about doing this.

Or is the reason my whirlaway didn't work just because it doesn't like cleaning concrete slabs and will never be able to do a very good job on them?

If anybody has any ideas or advice it would really help me out as i'm feeling a bit confused.

[trevor perry]

it could be a blocked jet as stated turn the thing upside down press trigger and check, it could also be the little rubber o ring in the whirlaway head you can tell if this has gone by turning whirlaway upside down and pressing the triger water will still come out of jets but water will also be coming out of a large hole on the central head , to fix this the all head has to be stripped down.

[peternathan]

you can get this if you go to fast as well!
i some times get it at the edges where only half the cleaner has covered try going a little slower or try a chris cross pattern with cleaner if what trevor said does not fix it

[davetherave]

cheers guys

[Ged]

flat surface cleaners/whirlaway are highly overated. they do not remove deeply ingrained lichen staining on flags or block. you need acid wash plus turbo lance most times. they are great for large areas of lightly soiled concrete or mossy block or tarmac.

Ged

[ray l]

I remember a post on here before stating if your p/washer isn,t 15lts or more this will happen. (alot of p/washers are only 11lts)

[Andy Foster]

Hi
As long as the nozzles are the correct ones for the washer, it doesn't matter what the ltrs/min are, your fsc should operate correctly.
Also, the black marks can be lichen which has buried itself deep into the stone, this can normally be removed by spot cleaning with a normal lance (turbo lance might damage the surface).  If however there is a large are to cover, there are off the shelf products which are fungicides as well as cleaners which will do the job.
Hope this helps

Andy

[davetherave]

Cheers guys for all the advice i really appreciate it.