Pressure washers and foam cannon selection advise.

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Spoilt01
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Pressure washers and foam cannon selection advise.

Post by Spoilt01 »

Hi All,

Iv been reading through some older posts on this topic and it seems that the CD foam cannon and karcher machines seem to be popular when coming
to foaming and cleaning your car. I understand a decent foam cannon goes miles I'm just not sure on the pressure washers and the options available.
It will be used for personal use (wash car when dirty rather than a weekly routine) can you advise me the pressure washers to avoid and what to look out for? I would not like to break the bank but at the same time buy something that will last. I do not want to spend really cheaply, not lasting and then regretting not getting a decent machine in the first place.

Many thanks!
lawrence
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Re: Pressure washers and foam cannon selection advise.

Post by lawrence »

There is some useful info in this thread http://www.vwclub.co.za/forum/viewtopic ... 0&t=182422

If I were you I would try and steer clear of the lower end models with plastic internals and get something with metal or brass internals, if you an afford it.

Also, HOW you use the machine will go a long way in helping it last longer.
lawrence wrote: After lengthy discussions with the guys from Karcher yesterday, this is what I have been told - some of which (like the duty cycle) I had no clue about :oops:

The K7 is the only machine with a brass cylinder head. It is rated at 160bar and has a duty cycle of 1 hour. This means it can be used for a maximum of 1 constant use and then must be shut off for at least 30 minutes - this is a water cooled machine.

The K5.2 and K5.7 supposedly have metal (not brass, not plastic) cylinder heads which are more durable than the plastic ones, but less durable than the K7. This however contradicts the pics Lambchop posted of the cylinder heads, so short of opening up a brand new K5.7 I don't know if the Karcher dude is just trying to pull the wool over my eyes. These are 130 bar machines (so currently too powerful (supposedly) for the new V2 cannons. These machines have a duty cycle of 40 minutes before needing to be shut down for 30 mins. They are also water cooled.

The K4, 3 and 2 series all have plastic cylinder heads, and a duty cycle of 30 minutes, before needing 30 minutes cooling off period - these are air cooled machine.

The K1 series is the same as above but with only a 10 minute duty cycle....

According to Karcher, some of the common causes of the failed cylinder heads are:

1. Exceeding the duty cycle - i.e. working the machine too long before allowing cooling off periods
2. Insufficient supply of water to the machine from your tap
3. Not bleeding the system of all air before turning it on
4. Pushing dirty water through the machine
5. Using 'unauthorized' chemicals in the machine

And then as lambchop mentioned, the constant on/off nature of these machines causes cracks in the cylinder head itself,or the seals therein to fail.
Shout if you still have questions after reading through the linked thread.
Spoilt01
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Posts: 213
Registered for: 14 years 8 months
Car Make: VW
Car Model: CitiRox 1.4i
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Location: Cape Town

Re: Pressure washers and foam cannon selection advise.

Post by Spoilt01 »

lawrence wrote:There is some useful info in this thread http://www.vwclub.co.za/forum/viewtopic ... 0&t=182422

If I were you I would try and steer clear of the lower end models with plastic internals and get something with metal or brass internals, if you an afford it.

Also, HOW you use the machine will go a long way in helping it last longer.
lawrence wrote: After lengthy discussions with the guys from Karcher yesterday, this is what I have been told - some of which (like the duty cycle) I had no clue about :oops:

The K7 is the only machine with a brass cylinder head. It is rated at 160bar and has a duty cycle of 1 hour. This means it can be used for a maximum of 1 constant use and then must be shut off for at least 30 minutes - this is a water cooled machine.

The K5.2 and K5.7 supposedly have metal (not brass, not plastic) cylinder heads which are more durable than the plastic ones, but less durable than the K7. This however contradicts the pics Lambchop posted of the cylinder heads, so short of opening up a brand new K5.7 I don't know if the Karcher dude is just trying to pull the wool over my eyes. These are 130 bar machines (so currently too powerful (supposedly) for the new V2 cannons. These machines have a duty cycle of 40 minutes before needing to be shut down for 30 mins. They are also water cooled.

The K4, 3 and 2 series all have plastic cylinder heads, and a duty cycle of 30 minutes, before needing 30 minutes cooling off period - these are air cooled machine.

The K1 series is the same as above but with only a 10 minute duty cycle....

According to Karcher, some of the common causes of the failed cylinder heads are:

1. Exceeding the duty cycle - i.e. working the machine too long before allowing cooling off periods
2. Insufficient supply of water to the machine from your tap
3. Not bleeding the system of all air before turning it on
4. Pushing dirty water through the machine
5. Using 'unauthorized' chemicals in the machine

And then as lambchop mentioned, the constant on/off nature of these machines causes cracks in the cylinder head itself,or the seals therein to fail.
Shout if you still have questions after reading through the linked thread.

Many thanks Lawrence I saved the mentioned thread (and many more others of yours) for future returns to recap. I guess logic would say the K5 or K7 would be worth my while, K7 being a killer without checking pricing as its the top model I guess. That being said the K5 with metal cylinder head has anyone had horror stories with them? Are they somewhat good or is it really K7 or nothing else?
Howie-WP
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Re: Pressure washers and foam cannon selection advise.

Post by Howie-WP »

I bought an el'cheapo Bosch Aquatek HP cleaner. As long as you don't completely abuse these things they should last (see Lawrence's post with common issues). I HP cleaned my entire house with it and still functions OK. For the occasional usage, the entry level should be fine. Make sure you have a proper cannon and decent cleaners.
Spoilt01
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Location: Cape Town

Re: Pressure washers and foam cannon selection advise.

Post by Spoilt01 »

Howie-WP wrote:I bought an el'cheapo Bosch Aquatek HP cleaner. As long as you don't completely abuse these things they should last (see Lawrence's post with common issues). I HP cleaned my entire house with it and still functions OK. For the occasional usage, the entry level should be fine. Make sure you have a proper cannon and decent cleaners.
I was kinda thinking along these lines too. I wont be working these machines it will be the occasional use really but will def be used with decent product.
lawrence
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Re: Pressure washers and foam cannon selection advise.

Post by lawrence »

When it comes to the cheaper units and trying to eek the most out of them, the do's and don't in my original post become even more important, especially a) bleeding out the air before use and b) taking cognizance of the duty cycle.
Howie-WP
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Posts: 14200
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Location: Cape Town, SA

Re: Pressure washers and foam cannon selection advise.

Post by Howie-WP »

lawrence wrote:When it comes to the cheaper units and trying to eek the most out of them, the do's and don't in my original post become even more important, especially a) bleeding out the air before use and b) taking cognizance of the duty cycle.
Agree. Mechanical sympathy and understanding. Then again, most people don't have that...... I try and look after my tools and stuff, so I understand the limitations and do not abuse the items.
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