[Joe Gro]

I live in Boston so this time of year the cars take a beating. Lots of road dirt and some salt with the melting snow.

I dont use car washes with brushes and have tried a local touchless wash. It seems to not do that much more than hosing the car down. There's still a fair amount of dirt left on afterward. Yes, its an improvement but it isnt like the car actually looks clean.

Curious as to others experiences

[GrussGott]

Originally Posted by Joe Gro

I live in Boston so this time of year the cars take a beating. Lots of road dirt and some salt with the melting snow.

I dont use car washes with brushes and have tried a local touchless wash. It seems to not do that much more than hosing the car down. There's still a fair amount of dirt left on afterward. Yes, its an improvement but it isnt like the car actually looks clean.

Curious as to others experiences

The problem is 3 fold:

(1.) Road film.
Salt, dirt, oil, gasoline, brake fluid, transmission fluid, et al - basically anything that leaks onto the road - mixes into a solution and gets sprayed onto your finish/ Only a degreaser will remove it, even when your car looks "clean". One thing is for sure: a pH neutral soap will NOT remove road film, just make it invisible, even with a contact wash. The next time dust or dirt hits it it'll stick like glue.

(2.) Heat Cycles.
The warming & cooling expands and contracts your paint - when it expands, cracks form in the clearcoat, the dirt gets pushed in there, and then when it contracts it closes the cracks & traps the dirt.

(3.) Other sticky shit.
Tree sap, overspray, anything acidic, tar, etc. It can bond to your clearcoat (or ppf) with those heat cycles.


So what do you do?

Well, if you can only go touchless car wash, then I'd find a U-spray place and do my own touchless:

(a.) Buy a sprayer filled with a degreaser like Road Warrior mixed 4:1, and spray down your car.
(b.) Let it dwell for 4-5 mins or more, but not dry or freeze
(c.) Spray it off.

Maybe repeat a few times if your car is really dirty, or increase the dilution if it's not too dirty.

The other thing you can do is, after that, do a contact rinseless wash. There are a bunch of threads that discuss that process.
----------------

TLDR
Touchless washes use an alkaline solution to dissolve off the dirt, but the effectiveness is going to vary massively due to product, the dilution, the way it's applied, and the quality of the equipment.

You can do a more consistent job yourself without much more effort.

[ENCBimmer]

The short answer is not really. I'm down south so I can't really speak to the winter-related road issues, but obviously we still have dirt, bird droppings, bugs and the like.

A touchless automatic car wash isn't really going to do anything. In your case, it likely isn't going to remove the things you need it to, and unless you hand dry it afterwards, is probably going to leave spots and the like that make the car look no better than when you went it.

The only time I really bother with an automatic wash (touchless) is if I am just trying to get pollen or something off, or something has just happened and I want to get it off quickly. In other words, buy the cheapest wash to just get the hose down.

I agree with the other post that says if you have the time just go to a self-wash place. It will be more thorough and saves you some effort off of hand washing.

[Joe Gro]

Originally Posted by GrussGott

The problem is 3 fold:

(1.) Road film.
Salt, dirt, oil, gasoline, brake fluid, transmission fluid, et al - basically anything that leaks onto the road - mixes into a solution and gets sprayed onto your finish/ Only a degreaser will remove it, even when your car looks "clean". One thing is for sure: a pH neutral soap will NOT remove road film, just make it invisible, even with a contact wash. The next time dust or dirt hits it it'll stick like glue.

(2.) Heat Cycles.
The warming & cooling expands and contracts your paint - when it expands, cracks form in the clearcoat, the dirt gets pushed in there, and then when it contracts it closes the cracks & traps the dirt.

(3.) Other sticky shit.
Tree sap, overspray, anything acidic, tar, etc. It can bond to your clearcoat (or ppf) with those heat cycles.


So what do you do?

Well, if you can only go touchless car wash, then I'd find a U-spray place and do my own touchless:

(a.) Buy a sprayer filled with a degreaser like Road Warrior mixed 4:1, and spray down your car.
(b.) Let it dwell for 4-5 mins or more, but not dry or freeze
(c.) Spray it off.

Maybe repeat a few times if your car is really dirty, or increase the dilution if it's not too dirty.

The other thing you can do is, after that, do a contact rinseless wash. There are a bunch of threads that discuss that process.
----------------

TLDR
Touchless washes use an alkaline solution to dissolve off the dirt, but the effectiveness is going to vary massively due to product, the dilution, the way it's applied, and the quality of the equipment.

You can do a more consistent job yourself without much more effort.

thanks for your comments

because of where I live I did go ahead and do PPF and ceramic

they definitely seem to help, but there are times when there is just a lot of crap on the car

I've read that rinseless washes dont work as well in that setting, but I'm not sure if thats really true

I wonder if using the degreaser you mentioned would be the best bet

[GrussGott]

Originally Posted by Joe Gro

thanks for your comments

because of where I live I did go ahead and do PPF and ceramic

they definitely seem to help, but there are times when there is just a lot of crap on the car

I've read that rinseless washes dont work as well in that setting, but I'm not sure if thats really true

I wonder if using the degreaser you mentioned would be the best bet

There's a lot of problems with the definition of "rinseless wash" - in the strictest sense it means only spraying solution on a very dirty car in a garage with no drain.

Admittedly I'm proposing a much modified version, albeit a portable version to better manage time, mess, tools, expense, etc ... so in general here's the process no matter the scenario:

(1.) Spray off the car with power sprayer to remove loose dirt & debris (a hydroshot if staying portable, can even use RW solution for this) - if there's only very light dust then you can skip this step
(2.) If needed, spray on a chemical decon like road film remover, dwell & rinse, and optionally iron remover and dwell & rinse (could be a foam cannon or pump sprayer application if you want to be fancy)
(3.) Spray on rinseless wash - not because you're doing a rinseless wash, because it's great at encapsulating dirt & dries clean
(4.) Contact wash with the multiple rag method, i.e., damp rags in a clean RW bucket that never touch the car after they're used
(5.) Blow dry - mostly just to remove water from the crevices
(6.) Dry with a drying aide, ideally a protectant or ceramic reload

Beware of some problems with PPF/ceramic:

* Water spots!
Since most ceramics are beaders vs sheeters, rain or water hits the car, beads, then dries as a bead which leaves a water spot. If you don't get these off they can etch your PPF and eventually it looks like the measles in the right light.

* Peeling
Depending on your PPF install (pre-cut vs custom) seams & edges can peel away - you'll want to get that taken care of immediately or it can spread. If you have visible edges or seams it's a good idea to inspect them with every wash.

[GForce55]

Wanted to bring this back forward. I plan to get a full body ceramic coat in a couple weeks and wanted to know if having the full ceramic coat makes those touchless washes more effective. I have a pressure washer as well, but I am super lazy and would rather use the touchless since soft touch is out of the question.

[malvern_man]

Originally Posted by GForce55

Wanted to bring this back forward. I plan to get a full body ceramic coat in a couple weeks and wanted to know if having the full ceramic coat makes those touchless washes more effective. I have a pressure washer as well, but I am super lazy and would rather use the touchless since soft touch is out of the question.

Do you mean touch less as in they just hose your car down and then you drive away.

[LOFT]

I have a professionally done graphene ceramic coating on my X5 45e.

I would say that the auto-touchless car washes do an adequate job of washing your car and everything beads up nicely and rolls off the car. But if you wipe the car with a microfibre cloth to fully dry it, you'll notice dirt, film and other residue on the cloth...even if the car looks clean.

On a nice day up here in the great Canadian north (like Boston) I'll take the car into the power wash bays where you can, soak, soap, hand wash, rinse and dry your car. This does a great job.

But I don't have an appetite for doing this on cold days, especially in winter...so you can do auto-touchless or pay a detailer to do a good wash for you.

In any case, no regrets about the ceramic coating. The car looks great...no need to wax and bugs & crap comes off easily.

[GForce55]

Originally Posted by malvern_man

Do you mean touch less as in they just hose your car down and then you drive away.

Touchless washes typically have an automatic wash that has a series if high pressure nozzles on it and they use foamy soap as well. Same thing as soft touch washes without the brushes.

[allinon72]

I work in the car wash industry…people really like to put touchless washes on a pedestal just because nothing "touches" the car. Well guess what…something has to pick up the slack to get the car clean, which usually means overly harsh chemicals, inviting a whole other set of problems. Add to the fact that most (not all) car washes are poorly maintained. Either way, depending on how dirty your car is, a touchless wash should be viewed as a touch up between hand washes.