JUNE 2019 UPDATE: Last time I cleaned my friend's driveway with a Karcher ~1800 PSI electric job (and stock wand) it took 6 1/2 hours. Never again I told myself. Since then, I got a Simpson 3200 PSI 2.5 GPM cleaner and then the Karcher surface cleaner. Last week I cleaned my friends driveway AND the sidewalk in front of her house with the new equipment and it took 3 hours. Being that the biggest concern with this surface cleaner is the nut coming loose, I periodically checked it and did not notice any problems with the nut. However, it seems that the plastic housing did turn 90 degrees over the course of the job, so I will continue to monitor it. NOTE: Once in a while I would accidentally let the surface cleaner lift and tilt off the ground and I would notice greater vibration coming from the unit as it's axis would tilt. I could imaging this extra vibration potentially shaking something loose, such as the nut, so I recommend keeping the unit consistently parallel to the ground. I also picked up a 33" wand extension here from Amazon and I highly recommend one for those who have a short wand. The longer wand will save your back. So I still recommend the Karcher surface cleaner. Any new developments and I will update this review. Original Review: I matched this surface cleaner up with a Simpson 3200 PSI 2.5 GPM pressure cleaner with 18" gun and 16" wand, approximately 24" total length. Initial impressions on fairly porous very dirty concrete driveway and sidewalk: Does a good job cleaning. As expected, I had to finish the job by reconnecting my spray wand and rinsing off everything that I cleaned with the Karcher. I found out that some areas were not sufficiently cleaned the first time around and I had to spot clean while rinsing. There is a learning curve with this product as is probably true of all similar surface cleaners. You have to figure out what method works best for you and how fast you should move. Ideally, you want to use the power of your machine to make the Karcher hover over the surface. Not really lifting off but not causing friction between the surface and the brushes that skirt the Karcher either. This is the method, I found, if you can manage it, that causes the least user fatigue. You also need to find the optimum speed at which you should move. This will depend on the PSI and GPM of your machine as well as the surface type and how dirty it is. For my driveway (very dirty), I needed to move pretty slow, maybe a couple inches per second. I was hoiping it would be faster, but it is what it is. Perhaps if I clean it more often, it will be quicker. One thing I will be investing in is a longer wand (to reduce bending over and user fatigue) and I am researching the ideal length. I am a little under 6 feet tall and obviously, the ideal wand length will be a function of user height. If someone has experience here, please let me know in the comments. As far as construction goes: Karcher is a German company, and like most German companies they seem to have a focus on engineering. They seem to do it right where it counts most. The biggest wear area, IMO, is the "bearing". AFAIK, Karcher uses a real sealed bearing and according to another reviewer, most other products in this price range don't really use a proper bearing. They cut corners and use a sleeve and/or washer for the friction area. If you have a product of this type, I'd recommend greasing the sleeve/washer often, perhaps even before or after every use to prevent rapid wear. Prior to buying the Karcher 15" surface cleaner, I looked at the Simpson and PowerFit (also rebranded as Yamaha for even more $$) surface cleaners. They used to be priced about the same as the Karcher, but are now 20-$30 more at the time of this review. The Simpson has a metal deck (which may rust?) but the same pseudo bearing as the PowerFit. The Karcher deck seems to be made of a durable plastic with a stiff brush skirt which keeps the water from spraying all over you. In addition to the metal sealed bearing, the Karcher uses a heavy rotating spray bar and brass/stainless steel fittings. There is a plastic nut top and bottom that holds the metal parts in the deck. I recommend checking these nuts regularly to make sure they are not loosening. And even though the Karcher is advertised as 15" (the deck is 15") the actual working measurement is closer to 12" based on the length of the spray bar. I assume all competing products have a similar discrepancy. In review, I recommend the Karcher over competitors based on their using higher quality components where it counts most (bearing). And right now they are actually less expensive which make the decision even easier. To maximize the benefit, I recommend using a machine as close as possible to the Karcher recommended max specs: 3200PSI and 2.7 GPM. While lesser specs should work, performance will be diminished and will make the job take longer. And at some point, if the machine is too small (like many of the electrics under 2000 PSI) it may not work sufficiently well to warrant the purchase. As to longer term durability, I will attempt to update this review in the future after I have had the product for a suffient time.
