Pressure Wash or Hand Wash when very dirty

F

Flynn

New member
Is Pressure Washing or Hand Washing when the car is very dirty or muddy recommended?



I'm taking the view that I would rather use the pressure washer (on it's lowest pressure setting) with a water and car shampoo mix to try to remove as much dirt as possible before I wash the car using a wash mitt. (as opposed to just trying to clean the mud and dirt off using the wash mitt in the first place)



The reason I ask is that I realise that the pressure washer is not as gentle as the wash mitt but I'm concerned that when you get too much dirt on the paintwork that the wash mitt is not going to be able to safely remove all the dirt without scratching. I'd rather go over the car first using the pressure washer (on it's lowest pressure setting) and then hand wash afterwards using a mitt.
 
if your concerned over mitt scratching.. 2 mitts with a 2 or 3 bucket method should suffice



every now and then, pressure washing is fine.. cuz in my ice planet at times, its needed :-)



I haven't had any direct negative side effects..
 
I would choose mitt washing with a foamgun over pressure washing. I kinda have bad feelings about blasting dirt against a paint finish. I would rather use several mitts during the wash instead and rinse often.
 
Neothin said:
I would choose mitt washing with a foamgun over pressure washing. I kinda have bad feelings about blasting dirt against a paint finish. I would rather use several mitts during the wash instead and rinse often.
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:werd: I would think a significant amount of the mud would come off from just the normal water pressure of a hose. The remainder should be safe to remove with a mitt wash if you rinse the mitt frequently and use more than one.
 
I don't like the idea of applying that much force to the dirt on my vehicles even if it *is* just shampoo or water. So I never use my pressure washers for this. I know plenty of people do though and if it works for somebody that's cool with me (not saying my method is the only way to go).



The safest way I've found to remove serious dirt (like what gets built up in the winter if you don't wash very often) is to use a foamgun in conjunction with a high-quality BHB. Use a strong shampoo mix. Shoot the foam through the bristles of the BHB while just barely contacting the surface of your panels (not hard enough to really bend the tips of the bristles). Move the BHB *just a little*, sorta "rocking" or "jiggling" it on the paint while still just *barely* contacting the panel. *DO NOT WIPE WITH THE BHB LIKE WITH A NORMAL WASH TECHNIQUE* That would cause marring. Just work the BHB across the panel by picking it up off the panel and setting it back down, rocking it the whole time. I raise it up and rinse it (using the foamgun) every few inches even though I hardly ever see any dirt on it. It takes more than one of these light passes to get all the dirt off so plan on going over the panel a few times- exercise self-discipline and don't get sloppy as you go (harder than you might think after the first few panels!). Then I follow up with a more normal foamgun/mitt technique.



The idea (as I'm always saying) is to dislodge the dirt with the least pressure necessary and then flush it away with the foam. The BHB will barely get any dirt on it, your rinse bucket will be almost dirt-free at the end of washing a very dirty large vehicle.



Yeah, this takes a very long time and you have to be very careful every second (literally every *second*). Watch for gritty dirt and take extra care with those areas. Stop and rinse the panel frequently and inspect your progress.



If any dirt doesn't come off, use a very mild clay like the Sonus Green to remove it. Be careful doing this, you don't want to drag grit across the panel once it's stuck in the clay. Sometimes you have to do one swipe with the clay, knead it, then a second swipe, knead it, etc.



It might take ten minutes to clean one panel, sometimes even longer. Still beats having to polish and redo the LSP.
 
Is there any substantial evidence that pressure washing a vehicle's paint finish causes any type of damage? I'm under the impression that any direct friction on a dirty finish causes micro swirls. I believe that you should always, at the very least, wash a vehicle's secondary layer off 1st before attempting to touch it with any object. Every detail manual I've read and every detail class I've ever participated in says to wash a vehicle down 1st. It's always been demonstrated with a pressure washer.
 
I don't really know if there's any proof that it could cause marring, but I'd also not want to a) blast dirt into tight recesses between panels and/or b) risk loosening any trim/weatherstripping with that kind of pressure. I just go for a more gentle approach to the whole thing. Thinking long-term and all that.



Might be different if I were doing customer's cars professionally. We used a pressure washer on inventory when I had the dealership, but it was a different situation. With my current vehicles, it's all about not causing any damage, including marring from washing. I'm sure disappointed if I have to polish out damage come spring!
 
I think you have to get the surface wet and can hopefully "float" off any dirt with the least bit of abrasiveness. That is where it is best to presoak with QEW or a good QD diluted with water.

I think you can use a pressure washer at low pressure if a full fleged hosing is not available.

Certainly one should never drag dirt around on a dry surface.
 
Flood the car with water, sort of sideways,lots of water,for a long time. Do not use presure hose. A number of owners manual tell you not to use a pressure hose. Just think about all that high pressure pushing on sand and mud into your paint job. Logic would dicate that damage will be done.
 
tabinha said:
Flood the car with water, sort of sideways,lots of water,for a long time. Do not use presure hose. A number of owners manual tell you not to use a pressure hose. Just think about all that high pressure pushing on sand and mud into your paint job. Logic would dicate that damage will be done.
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I don't think this is accurate. Do you know of such an owner's manual that says not to use pressure to clean a car? EVERY tunnel car wash, EVERY touch free/less car wash and EVERY self serve car wash uses high pressure to attempt to clean each car. Wouldn't people go around sueing cars wash woner everywhere for damaging their cars if everyones finish was getting destroyed? You can spray a car down with water for hours with 100's of gallons of water and it's still not going to clean it any better. I'm not trying to beat a dead horse and offend anyone, but there has to be something substantial indicating that pressure washing a dirty vehicle's paint will cause microscopic damage.
 
David Fermani said:
EVERY tunnel car wash, EVERY touch free/less car wash and EVERY self serve car wash uses high pressure to attempt to clean each car. Wouldn't people go around sueing cars wash woner everywhere for damaging their cars if everyones finish was getting destroyed?
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Well, consider than all of the above are pretty lousy ways to clean a car and that most people don't know/care. One trip through a brush/fabric strip type tunnel wash or one contact with the brushes/pads at a self-serve will mar paint yet people don't mind. Heh heh, IMO the finish of most cars *is* getting destroyed; 99.9999999~% of cars are so marred up I wouldn't be caught dead behind the wheel (I've been known to do major compounding/polishing on rentals). It's all relative and anyone who cares enough to sue over their car's cosmetics would probably care enough to just treat it right in the first place.



And the high-pressure jets at the washes are nothing like the pressure my Karcher pressure washers generate if I turn them up enough to do a thorough job like I've done on some undercarriages. If I turned them up all the way they'd blow moldings/etc. right off the car.



Heh heh, sorry, I don't mean to come across all :argue: and I fear that's what's happening :o I can see using a pressure washer to get the worst/most abrasive dirt off without rubbing it into the finish and upon reflection I think that the way I treat my vehicles just isn't practical for most people, including a lot of Autopians. Using the pressure washer for the worst of the grime quite possibly *would* be better than what most people do. Just be careful so you don't do any damage.



Oh, and I've never had any great success with presoaking, even with the Stage I prewash stuff from Stratmosphere or with my foamgun. Yeah, it helps a little, but never as much as I'd like. Best thing is to use a LSP that stuff doesn't stick to and to wash frequently so the grime doesn't build up too much.
 
Because of a local drainage bylaw, I can't rinse any chemicals off of a car, so if it's really dirty (which they all are around here), I hit it with a pressure washer first with straight water to get the mud off, then follow with a two bucket QEW. I don't know of any alternative for my specific situation becasue I'm sure as hell not taking a wash mitt to caked on mud! The pressure washer helps get the heavy guck out of the wheel wells and wheels also. I'd guess that both a hand wash or heavy spray on serious dirt could cause some fine scratching, and the best bet is to keep the car protected before that happens so that you're scratching wax instead of paint.
 
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