On 01/04/2012 20:24, Another Dave wrote:
Hugo Nebula wrote:
Reading car forums, the overwhelming opinion is that a pressure washer
is needed to wash one's car properly. So I went and bought a cheap
Halfords one, complete with snow foam attachment. The results were
disappointing to say the least.

I know it's not a mega powerful one, but I was amazed at how low the
pressure was out of the nozzle. I was certain my hose gave a more
powerful flow, so I did an experiment and timed how long it took to
fill a bucket, and therefore what the flow rate is from my tap. It
amounts to 1,000 litres per hour, nearly three times the flow rate of
the PW. Some of the best pressure washers only appear to give half of
that.

Am I missing something here? Is pressure a function of the flow rate,
and if so, what's the point of a pressure washer if it gives less than
mains pressure?

I believe they were invented as a water SAVING device. They don't use
much water but should produce a high pressure jet. Mine certainly does.

Is there a leak at the junction of the wand and the machine?

Another Dave

Ok a non tech answer :-)
And I dont recommend this.
I have a cheap one but was more than happy with the patio results to the
point I got carried away and decided to clean the plastic patio
table....It now has grooves cut into the table top where I used the PW,
this wouldnt have happened with a garden hose, I could have ripped
through it given a few more minutes.
Last year in hot weather (bare feet) cleaning the slabs.... I accidently
blasted my foot with the jet....damn painful it was, again much more
pressure than a garden hose.
In both instances it used much less water than a hose.