what to look for in a water blaster ?

Forums › Home Workshop DIY › what to look for in a water blaster ?

xlinknz

1130 posts

Uber Geek

Trusted

#177830 15-Aug-2015 15:57

I need a water blaster for general use esp oil stains on a driveway

Seems Karcher & Nilfisk are the 2 big brands esp for accessories, I am leaning towards Nilfisk as they have an alloy pump & better reviews esp for models > $500

Ideally I'd like a long e.g. 2m + extension as well to use carefully on the house

What have peoples experience s being esp in what features to get etc

1 | 2 | 3

8965 posts

Uber Geek

#1366993 15-Aug-2015 16:10

Went through this a few years back, no doubt models have changed a bit since then though. At the time, the low end Karchers had a plastic pump, but all the Nilfisk had metal.

Karcher had a much better range of accessories though, which ended up as the deciding factor...

andrewNZ

2487 posts

Uber Geek
Inactive user

#1367004 15-Aug-2015 16:23

The main thing to look for in a waterblaster is high flow rate (l/min). The small cheap ones are like using a toothbrush.

Batman

Mad Scientist
29773 posts

Uber Geek

Trusted

Lifetime subscriber

#1367029 15-Aug-2015 17:11

beware it can remove paint!

1eStar

1604 posts

Uber Geek

#1367107 15-Aug-2015 18:52

Often they come with a short, poor quality hose. Either get an extension made up or replace it with a long hose. It's ultra convenient not having to move the motor unit all the time, and is good for cleaning your roof etc.
With regard to the oil spots, if they're fresh, put talcum powder on to soak up as much as possible. If old stains, pour neat detergent (dishwash) on to the stain and let it sit for a while before you waterblast them off.

jonathan18

7413 posts

Uber Geek

ID Verified

Trusted

#1367149 15-Aug-2015 20:39

If you get one of the cheaper models, be careful of running it for too long (or just get a more grunty model!).

We own an entry-level Karcher, and managed to stuff the first one. Mitre 10 did fix (replace?) it, and warned us it was probably running it on an extension cable for too long (said we should have used an extension cable with thicker wiring - would this have made a difference?).

Since that happened, I've just been careful not to use it for ages and it's still doing fine about 10 years later. And, to be honest, it's been more than powerful. Next time I'd get a bigger one, but more to avoid this problem than a concern at its inability to clean properly.

scuwp

3888 posts

Uber Geek

#1367155 15-Aug-2015 21:02

Why not just hire a commercial one if its just a seasonal cleanup?

Lazy is such an ugly word, I prefer to call it selective participation

xlinknz

1130 posts

Uber Geek

Trusted

#1367193 15-Aug-2015 22:01

Thank you all for the replies

Did anyone find accessories such as patio and or rotary cleaners useful ?

jonathan18: If you get one of the cheaper models, be careful of running it for too long (or just get a more grunty model!).

We own an entry-level Karcher, and managed to stuff the first one. Mitre 10 did fix (replace?) it, and warned us it was probably running it on an extension cable for too long (said we should have used an extension cable with thicker wiring - would this have made a difference?).

Since that happened, I've just been careful not to use it for ages and it's still doing fine about 10 years later. And, to be honest, it's been more than powerful. Next time I'd get a bigger one, but more to avoid this problem than a concern at its inability to clean properly.

Strange -Did they say why running it on an extension chord was an issue ?!

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

andrewNZ

2487 posts

Uber Geek
Inactive user

#1367221 15-Aug-2015 22:51

Long extension cords cause voltage drop due to resistance (all cables have resistance and suffer from varying degrees of voltage drop), which means the machine draws more current. More current means more heat, and potentially more voltage drop. Heavier cords have less voltage drop.

As for patio cleaners, my Nilfisk one is actually fairly good. From memory, I found it less effective on concrete because it "flooded".
I think the nozzle i found most useful looks like a jet, but in practice it spins and forms a cone. It's pretty effective.

jonathan18

7413 posts

Uber Geek

ID Verified

Trusted

#1367267 16-Aug-2015 09:00

I use my in-laws' patio cleaner with my Karcher and would recommend them, if cleaning your deck is one of the purposes of getting a water blaster.

Three key advantages I see as a result of having a wider coverage and set spray distance:
* faster
* more consistent results
* little (nil?) chance of damaging the deck due to spraying too close to the wood

They'll not deal with significant issues, but are great for overall cleaning.

(Just a warning: I used dish washing detergent on the deck, which worked well in helping, but I squirted it on in advance to save time and it left stains; next time I'll just do it as I work on a particular area.)

Fred99

13684 posts

Uber Geek

#1367345 16-Aug-2015 11:17

Water blaster isn't the greatest thing for removing soaked-in engine oil from concrete driveways. I haven't found anything which works much better than supercheap auto engine degreaser spray, hard scrubbing, hosing down, then repeat.

I had a cheap K'archer ($250 or so retail, $160 on special), made in China. Cheapest model (2.xxx?) with "turbo" head" - which do work effectively. It stopped working due to a faulty/sticky pressure switch, I managed to pull it apart and clean up the switch - that was a major mission as I had to partly disassemble the pump itself to get at the switch - crazy design - re-assembling it was a major mission. IMO they certainly don't make these things with view to them ever being maintained/fixed, but there's no way the pump was "plastic". That was a few years ago - it's still working - I gave it away to my FIL, as I was unexpectedly given a larger K'archer blaster by Placemakers' loyalty card programme. I would have preferred a Nilfisk - there seems to be near consensus that they're better made, which ties in with the higher price. I'd never pay full retail price for one of these things - they're almost always being discounted somewhere, Supercheap, Mitre 10 etc.

The smaller blaster did much the same job, if they say 1500psi or whatever, then it probably is, if they say x litres per minute flow rate, then it probably is. The larger unit pumps more water and is a bit more effective. Probably more importantly, it seems to run at lower rpm and sounds much less stressed. There will be in the manual and possibly printed on the label a service rating and instructions, probably something like 3 or 5 minutes operation, then turn it off to let it cool down for xx minutes. If you follow that rating, then it's clear that the small units are designed for small jobs only, and if you want better, then more $$$ needs to be spent.

RunningMan

8965 posts

Uber Geek

#1367347 16-Aug-2015 11:21

Fred99: [snip] There will be in the manual and possibly printed on the label a service rating and instructions, probably something like 3 or 5 minutes operation, then turn it off to let it cool down for xx minutes. If you follow that rating, then it's clear that the small units are designed for small jobs only, and if you want better, then more $$$ needs to be spent.

This is really important. The larger ones will happily go for hours at a time without issue - the smaller ones will only do it once or twice!

xlinknz

1130 posts

Uber Geek

Trusted

#1408789 18-Oct-2015 19:59

All

Thx again for the replies :)

My short list is current modest mid range Nilfisk or a Bosch [the later has an adapter take Karcher accessories]

The Nilfisk is 1400w, 7.3L/min, 1740 psi
The Bosch is 1700w, 6.17L/min, 1885 psi

I'm leaning towards the Bosch as it has a more powerful motor, higher psi but for some reason a slightly less flow rate, any ideas ?!

andrewNZ: The main thing to look for in a waterblaster is high flow rate (l/min). The small cheap ones are like using a toothbrush.

Which Nilfisk did you have ?

Sideface

9367 posts

Uber Geek

Trusted

Lifetime subscriber

#1408793 18-Oct-2015 20:09

xlinknz: ... I'm leaning towards the Bosch as it has a more powerful motor, higher psi but for some reason a slightly less flow rate, any ideas ?! ...

The Venturi Effect

Pump fluid through a smaller hole - you get get higher pressure, and less flow.

Sideface

TonyR1973

199 posts

Master Geek

#1408893 18-Oct-2015 22:26

A waterblaster is the very last thing you should use on concrete driveways unless you like ever decreasing periods between having to do it again and the inevitable ugly finish when you've ripped away all the sand.

TonyR1973

199 posts

Master Geek

#1408895 18-Oct-2015 22:29

andrewNZ: Long extension cords cause voltage drop due to resistance (all cables have resistance and suffer from varying degrees of voltage drop), which means the machine draws more current.

Someone should tell Ohm's Law that it's wrong.

1 | 2 | 3