hugh wrote:
In message , Graham.
writes
On Sun, 01 Apr 2012 19:13:17 +0100, The Medway Handyman
wrote:

On 01/04/2012 19:08, Rod Speed wrote:
The Medway Handyman wrote
Andrew Gabriel wrote
Hugo 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

Really?
I thought a problem with them for this purpose is the pressure can
take the paint off.

Urban myth.

Nope, fact, at least with motorbikes.


I sold pressure washers for 30 odd years. I only know of on instance of
paint removal & that was a Lada the owner had hand painted.

'If' a pressure washer takes paint off - the paint was coming off anyway
- the pressure washer just brought the date forward.

Well my wheel-nut covers were fine before they washed my car after
servicing it last time. Perhaps they used an angle grinder and not a
PW? And no Skoda jokes Mr Lang!
http://www.flickr.com/photos/g3zvt/6...ream/lightbox/

Funnily enough, it's going in for a service in the morning so I will
remember now to tell them not to bother washing it.
What should I use to spray the plastic covers with?

Peugeot dealer wanted to pressure wash my motor caravan when I took it
in for service. Polite but firm No Thank You. I did explain why but I
bet they are still doing it.

I do mine that way every year.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On 01/04/2012 16:34, Mentalguy2k8 wrote:

"Bill" wrote in message
...
In message , Hugo Nebula
writes
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?


They, as the name suggests, provide extra pressure and not flow rate,
so I would expect an open hose to provide a higher flow rate,
otherwise they would be sucking water out of your mains.

I use a middle of the road Karcher and it is marvellous, fetches
paving slabs and concrete back to a nice crisp finish and clears most
of the dirt off the car.

Those are mainly what I use mine for, plus with not-so-great drainage in
my back garden, I can clean it all without flooding the garden because
it uses less water than a hose. The patio looks like new at the moment,
I don't think anything else would bring it up that clean.

I'm assuming the best way to compare tap versus jetwasher is the bar
measurement rather than flow rate. I think my washer is about 120bar,

Have a look at the FAQ. The way to compare them is with the pressure
*and* flowrate - its the product of the two that does the work...

that's way more than a tap. You can stop a tap running with your thumb
over it, you ain't stopping a jet from these machines.

You would have a hard job stopping most cold mains taps with your thumb!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

The Natural Philosopher wrote
Bill 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?

They, as the name suggests, provide extra pressure and not flow
rate, so I would expect an open hose to provide a higher flow rate,
otherwise they would be sucking water out of your mains.

I use a middle of the road Karcher and it is marvellous, fetches
paving slabs and concrete back to a nice crisp finish and clears
most of the dirt off the car. If you have it on a pencil jet and it
cuts the rubber trim around the windows then it is OK. A problem I had when I first used mine years ago. Quite good
at taking paint
off painted bumpers too if there are any stone chips.

add in getting winter lichen off the garden furniture..
not bad at house paintwork and the windows, too.

And blasting off the wasp nests too.

On 02/04/2012 02:15, The Natural Philosopher wrote:
Martin Brown wrote:

A small amount of water carrying a large amount of kinetic energy can
do a lot of damage. I would not use one on my car as I don't want to
grit blast the surface or strip the paint. YMMV Fine for use on dirty
patios though and stone doesn't suffer much from additional scratches.

That's why you vary the distance to the target and the nozzle dimensions.

Indeed, but it isn't a tool I would like to use on good car paintwork.

They are not sandblasters.

That depends how much sand and grit there is stuck on the car already.
Mine picks up a lot of salt and mud (and this time of year muck) from
local roads. Using a pressure washer would grind it into the paintwork.

--
Regards,
Martin Brown

Martin Brown wrote
The Natural Philosopher wrote
Martin Brown wrote

A small amount of water carrying a large amount of kinetic energy
can do a lot of damage. I would not use one on my car as I don't
want to grit blast the surface or strip the paint. YMMV Fine for
use on dirty patios though and stone doesn't suffer much from
additional scratches.

That's why you vary the distance to the target and the nozzle dimensions.

Indeed, but it isn't a tool I would like to use on good car paintwork.

More fool you.

They are not sandblasters.

That depends how much sand and grit there is stuck on the car already.

Nope.

Mine picks up a lot of salt and mud (and this time of year muck) from
local roads. Using a pressure washer would grind it into the paintwork.

Nope, it blasts it off.

Using your silly line, there isnt any way to clean a car
like that, because it just 'grind it into the paintwork'.

The whole point of cleaning it is to get it off instead.

On Sunday, 1 April 2012 15:28:07 UTC+1, 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?
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have I strayed"?

Logic says that in simple terms a PW must deliver either the same or less water from the tap than the tap is able to produce under normal conditions - PWs don't "suck" the water out of the mains any faster (do they)?

It its really disappointing, I'm wondering if you have got it plugged in and turned on...

Matt

"The Natural Philosopher" wrote in message
...
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.

Wonder if you made the mistake most new pressure washer owners do, and
assume you can clean a right ****ted up car back to showroom shine with just
a jet of water, and maybe a little detergent sprayed on,

You still need a brush/sponge to clean the dirt off the paintwork, and the
pressure washer to get under the wheel arches, ally wheels and so on,

That's the reason car washes use rotating brushes instead of just jets of
water... mind, round here most car washes have replaced the
electric/hydraulic driven rotating brushes with illegal immigrants holding
sponges and shammy leathers for some reason.

On Apr 1, 7:13*pm, The Medway Handyman
wrote:
On 01/04/2012 19:08, Rod Speed wrote: The Medway Handyman wrote
Andrew Gabriel wrote
Hugo *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

Really?
I thought a problem with them for this purpose is the pressure can take the paint off.

Urban myth.

Nope, fact, at least with motorbikes.

I sold pressure washers for 30 odd years. *I only know of on instance of
paint removal & that was a Lada the owner had hand painted.

'If' a pressure washer takes paint off - the paint was coming off anyway
- the pressure washer just brought the date forward.

SO they can take the paint off, then. Glad we cleared that one up.

MBQ

On 02/04/2012 02:20, The Natural Philosopher wrote:
The Medway Handyman wrote:
On 01/04/2012 17:41, Andrew Gabriel wrote:
In ,
Hugo writes:
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

Really?
I thought a problem with them for this purpose is the pressure
can take the paint off.

Urban myth.

Not a myth, because I have done it: If the paint is already loose they
will take it off, but they wont take paint off a car at the sort of
pressures and distances you normally use a toy one at.

A high pressure industrial jet jet will cut through steel plate...its
all a question of muscle.

http://www.youtube.com/watch?v=bW10fOVIozE


That's Ultra High Pressure. 6,000 bar +.



--
Dave - The Medway Handyman www.medwayhandyman.co.uk

The Medway Handyman wrote:

The Natural Philosopher wrote:

A high pressure industrial jet jet will cut through steel plate...its
all a question of muscle.

http://www.youtube.com/watch?v=bW10fOVIozE

That's Ultra High Pressure. 6,000 bar +.

I'm amazed you don't get an "exit wound" that's significantly wider

On Mon, 2 Apr 2012 03:57:55 -0700 (PDT)
larkim wrote:

On Sunday, 1 April 2012 15:28:07 UTC+1, 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?
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have I strayed"?

Logic says that in simple terms a PW must deliver either the same or
less water from the tap than the tap is able to produce under normal
conditions - PWs don't "suck" the water out of the mains any faster
(do they)?

Interesting thought, that: If so, then any other tap open in the house
would become a suction point instead of a water supply!

We lived in a place in the US once where the water main ran down the
middle of the street, and each opposing pair of houses were supplied
from one 'T' on the top of that main. Cold taps were supplied
directly off the main, via a pressure regulator. The house opposite us
had automatic sprinklers, and the folks who came every autumn to bleed
it out never got the hang of where to attach their air compressor. For a
day or so afterwards, we had explosive cold taps whenever we turned
them on, until the air pocket had bled out.
--
Davey.

On Mon, 02 Apr 2012 09:44:55 +0100, Martin Brown
wrote:

Mine picks up a lot of salt and mud (and this time of year muck) from
local roads. Using a pressure washer would grind it into the paintwork.

That's why I use the fan setting first, to wash off the grit and loose
bits.