Accumulator said:
When I use the foamgun in a way that speeds up the wash, I get marring; doing *anything* in a remotely time-efficient way always leads to marring for me
But when I use it in a time/labor-intensive manner it greatly *reduces* the wash-induced marring.
This is indeed what I have found too with extensive testing of foaming products used through a foam gun (Autobrite Foam Lance with pressure washer). I have tried several foams and have found that the higher foaming foams tend to do less than the foam which produce a "runnier" solution on the car which has less iof a dwell time but will run off the paint - wetting the dirt and lifting a notable amount of it in my experience.
However, as you rightly point out, this is not to be seen as a way to speed up washing - it should be considered as a way to aid marring free washing but removing as much of the surface dirt and grit (at this time of year) as possible before a mitt comes into contact with the paintwork. A foam with the ability to wet this soiling can also loosen and remove it as the foam runs off, and rinsing afterwards further removes the loosened dirt better than rinsing alone with plain water - this has been demonstrated numerous times but does slow the wash process up as you do have to take your time and be careful to get this stage correct. Using a warm water pressure washer further increases the effects of foam in my experience.
Indeed, quite often I will spend a good 20+ minutes on foaming alone... foam the car, allow to dwell for five minutes, rinse and repeat if necessary and sometimes depending on the time of year a mitt wash is not needed but just now in winter, this leaves a nearly clean car for the mitt wash to finish. I use foam from a company called Bilt Hamber in the UK, which for me have produced a foam which is not thick but rather a little runnier but seems to clean more effectively than others I have tried.
David Fermani said:
I disagree. It usually takes me more time. Down here, I can't let anything sit on the paint more than 2 minutes without causing major streaking, let alone pre-soaking the entire vehicle. 1/2 the soap would be dry before I washed 1 side. Unless you're pre-soaking your vehicle with heavy cleaners, I don't feel it loosens up any dirt. It might help loosen up bugs, buy plain water does that too. I see a foam gun as a tool that has the potential to eat through tons of product without delivering anything more than a novelty.
Something I have always thought about the use of foam guns is that they must be region dependent - living in the UK, it rarely gets warm of sunny enough to worry about this and I wash my cars indoors in any case which further lessens the issue but outside in hot sun, I would be sweer to recommend foaming for the reasons you have mentioned.
However, I would not go as far as to say that foaming does not achieve anything more than water alone does in all conditions - certainly not where I live or in my washing conditions, where prefoaming does loosen road film and aid the cleaning process as well as helping to remove surface dirt and grit (yes water does this too to an extent, but I have found in my experience that foaming achieves a better result and has in testing reduced the amount of marring induced when I switched to non-ideal mitt wash methods to really put foaming to the test).
Some foams for me, as I have alluded to above, present nothing more than novelty value and these would appear to be the ones that procue a thick, almost shaving foam like foam on the car - look cool, cleans sod all. Whereas a runnier foam that wets the paint and dirt more has greater effect so product choice in this respect is important... Dwell times are also key with the foam I use, leave it for 5 minutes and you'll get a better result than leaving for one minute: and this brings us full circle back round to your issue of weather conditions, as I imagine leaving a foam to dwell for 5 minutes in the Florida sun is akin to dousing the car in concrete and watching it set!! So its very much weather and wash condition dependent.
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