How Much Dawn Dish Soap to Wash a Car?

Great reset and thanks Ski!

I read every single word of every post in this thread and it was a fascinating discussion. At the end it got into discussing things like whether an LSP inhibits the affect of Iron X and strayed away from the original intent of PiPUK's first post but it offered some great chemical based postulations and demonstrated evidence of how difficult it is to be insured you have, in fact, REMOVED LSP. If you are inclined to spend the next hour and a half reading through it, key on the word "surfactant".

I think what i gained as a bottom line definitive is...

To remove an LSP, the single best way is to machine abrade it off.

I also came from Zaino a long time ago in a far off galaxy and if i remember correctly Sal Zaino suggested Dawn as a way to remove surface oils, grease, dirt etc. the FIRST time you used his products.

You can polish it off, or you can use a grease and wax remover. I think the later is much faster and easier if the paint doesn't need polishing.
 
Could this be why come back from dealership "details" all swirled up? :)


I should show up at the Cadillac dealership demanding a re paint for my car because after 19yrs. of following their crummy advice my cars finish has been ruined. Lol.

And I demand they ship it back to Detroit and do a complete frame off re paint.. Factory bake, nothing less. That advice in the owners manual should've lead to a massive recall.😏
 
Calm down Skippy...I don't recommend using Dawn either. And, it doesn't work for me, because I don't use it...I was merely pointing out that Dawn was recommended as far back as then. Not to remove Zaino, but as a wash prior to using. Just looked on Zaino's website and it's still THEIR recommended first step...not mine.
Perhaps I'm having eye sight issues, but, just finished reading almost everything on their (Zaino's) website and saw NOTHING about using Dawn.... NO mention of Dawn. Can you please send me the information about using Dawn on their website? Feed back please
 
Perhaps I'm having eye sight issues, but, just finished reading almost everything on their (Zaino's) website and saw NOTHING about using Dawn.... NO mention of Dawn. Can you please send me the information about using Dawn on their website? Feed back please

Since I can't post a link because of the form rules...type Google in your address bar, and once Google opens type in Zaino. When the Google results are displayed, you will see Application Tips...it's in there. It is also listed under the FAQ topic: What should I do before applying...it says this; The first thing you should do is wash your vehicle thoroughly with Dawn (or comparable) dish soap to remove any wax, grease, and oil from your paint
 
Just chiming in as I believe I may have had a notable roll in convincing people that Dawn (and similar) are not the magic stripping solutions that they were once touted as.

First off, you could call it a degreaser. Of course the same arguments can be applied to most car wash products, glass cleaners and such. In the case of Dawn, it is a mostly neutral blend of surfactants. The surfactants are specifically intended to act upon oil soils and thus can be considered degreasers (if you wish to take it to that extent). It follows that almost anything that contains surfactants could thus be described as a 'degreaser'. So I think one needs to take care here. Dawn and similar will intentionally be mild because they need to be safe for repeated and prolonged skin contact. Let me guarantee you Dawn has been much much more thoroughly tested, in this regard, than any 'car shampoo' product on the market. I might hazard that Dawn has been more thoroughly tested than almost every car shampoo when added together! This skin contact thing is important because you cannot have excessive degreasing character - it would result in oils being removed from user's skin which would lead to all manner of skin conditions and irritation. Trust me, this does not happen with Dawn. Car shampoo, well there is another matter altogether. As above, there won't be a single one on the market which has done testing, on the level of Dawn, to demonstrate the mildness. I am not saying that they are needlessly aggressive, but it is simply wrong to suggest that Dawn is a notably more potent degreaser than your average car shampoo.

Moving on, in the same vein, the colloquially termed 'car soaps' are often much more potent degreasers than a Dawn type product. Often this term can be used to describe notably alkaline and solvent containing products and it should not take a rocket scientist to appreciate that there is a good degreasing capacity there. Overall, I would just like to encourage that we stop trying to vilify Dawn because "it's a degreaser and my car soap is not" - in the vast majority of cases, this simply is incorrect.

As for how Dawn does actually behave - other have already linked to threads where I have made big contributions on the subject. Briefly, Dawn (and other good washing up products) will have a characteristic which is mostly ignored - they will inhibit water spotting. This is essential in the primary application because water spotting makes dishes look dull and not properly cleaned. The way that this is achieved is by the use (mainly) of surfactants which will basically stick to surfaces. They (temporarily) adhere and they ensure that water on the surface forms a sheet (this is a hydrophillic surface where water 'sticks' - not the commonly discussed 'detailer' sheeting where you have a moderately hydrophobic surface where the water runs off as a sheet, as opposed to breaking into beads as would be seen on a more hydrophobic surface). In so doing, the water evaporates away evenly and you don't get spotting. This is the reason why you don't get dishwash products which make the water bead, it is just a bad idea. Anyhow, this then transfers to your automotive use. The same thing applies, these surfactants will adhere to your paint and will tend to make it look like the surface is no longer water repellent. In fact the reality is that your LSP is almost certainly still quite content, hidden under a temporary layer of surfactant. I have repeatedly confirmed this with so called 'stripping solutions' where I have been able to show a big degradation in the beading which can subsequently be recovered with a quick IPA wipe or a very thorough rinse. Others can attest to the same results (which is probably why we got traction with the concept!).

For my part, this sort of behaviour should actually be desired for a detailer. Like with a dish washer, it will decrease the tendency towards water spotting (and we all know that water spotting is bad). Unfortunately, I know of nobody who actively pursues this for a general purpose car shampoo because many users will (wrong) perceive that their LSP has been harmed. In fact, I am fairly confident that the few products out there which do behave in this way are, either knowingly or otherwise, sold as strippers (and I have yet to find one which genuinely is).

So you should not fear Dawn or similar products. The majority of the cleaning capacity will be provided by chemicals which are the same or comparable to those in your auto specific products. The apparent diminishing of water repellency is very likely going to be a misunderstanding, thanks to Dawn being specifically designed to inhibit water spotting.

That is my take on it, your mileage may vary, of course! For anyone reading and thinking you might like input on any similar topics, fire me a PM if something comes up. Life is somewhat busy these days so I don't get as much forum time as I might like!
 
These Dawn threads are always amusing. How Dawn at the same time is too harsh to use on your car, will wreck your paint, wreck your trim, etc., but at the same time millions of people put their hands in it, and stressed aquatic oil-covered birds are cleaned with it.

Dawn is simply a mild detergent, not too different from a car wash soap (Dr. G from Optimum did point out at one time that dish wash soaps frequently use sodium thickeners which are not the greatest for your paint, but I'm sure there are plenty of car wash soaps that do the same).

The thread was already linked where Dawn's "stripping" myth was busted, and I see PiPUK is looking at this thread, so I'm sure he'll chime in with his 2 cents (his posts are usually worth at least 50 cents ;) )

Edit: Guess he beat me to it.
 
So my owners manual is right.

See, I told you guys!😏lol. J/k
 
(Dr. G from Optimum did point out at one time that dish wash soaps frequently use sodium thickeners which are not the greatest for your paint, but I'm sure there are plenty of car wash soaps that do the same).

Sodium thickeners - actually it is typically nothing more than common table salt. The use of this will depend on the activity level of the product. If it is a budget product, it may well be 'runny' with just the base surfactants. The consumer tends to link viscosity and quality so it is a no-brainer to use salt to thicken it up. More expensive products do not need it as they will have plenty of activity to build viscosity on their own. (I suppose I should make clear that this doesn't apply to all surfactants, just the ones common to a dishwash/shampoo)

Salt is an interesting topic. It isn't really so good for the vehicle but you tend to have small percentages in the product and these are then diluted in the bucket. I would hazard to think that the actual percentage in your wash is so low as to be practically irrelevant (and your vehicle will encounter much more salt in normal use, especially during the winter). It is also worth mentioning that many of the surfactants have appreciable levels of salt contamination - it takes a very specialised product to genuinely eliminate salt (i.e. it costs a whole lot more and gains almost nothing!).

A bit of a digression but you have to be cautious about how much to concern yourself with technical. I have seen someone selling a very expensive shampoo and justifying it because is is sodium lauryl sulphate/parben free - things which may be of merit in personal care, but, at least from my understanding, will have absolutely no benefit to a car shampoo. Sometimes even the brands can get confused as to what and why they are selling!!
 
Always to good to see PiPUK chime in.

Thank you Sir...

Bill
 
Anyone want to reveal how many auto cleaning products have the secret ingredient "kerosene?" Just wondering.
 
Anyone want to reveal how many auto cleaning products have the secret ingredient "kerosene?" Just wondering.

It would be an odd shampoo to contain kero. Polishes and waxes - whole different kettle of fish! I suspect that it will be the case that more of these products do contain it than do not. Tar removers (proper ones, not the water based ones!) will almost always have kero present - in the UK the most popular product, as you would believe from detailing forums, is just basically kero/xylene/white spirits, and people more or less soak their vehicles in it.
 
So PiPUK... I got to reading your previous write-up...
Looks like you came to the conclusion that even IPA doesn't remove wax or sealant? If this is true how can we have gone all these years installing coatings over an IPA prepped surface without the coatings failing regularly?
 
So PiPUK... I got to reading your previous write-up...
Looks like you came to the conclusion that even IPA doesn't remove wax or sealant? If this is true how can we have gone all these years installing coatings over an IPA prepped surface without the coatings failing regularly?

IPA does a fine job of removing polishing oils, but not LSPs. I would think most cars have been polished in preparation for the coating so the IPA would not be removing any LSP, just polishing product residue.
 
So PiPUK... I got to reading your previous write-up...
Looks like you came to the conclusion that even IPA doesn't remove wax or sealant? If this is true how can we have gone all these years installing coatings over an IPA prepped surface without the coatings failing regularly?

Um...because everyone polishes before applying coatings?
 
So PiPUK... I got to reading your previous write-up...
Looks like you came to the conclusion that even IPA doesn't remove wax or sealant? If this is true how can we have gone all these years installing coatings over an IPA prepped surface without the coatings failing regularly?

I know the IPA wipedown is to remove the oils from polishing. Which must be chemically different than a wax /sealant. And the mechanical abrasion from polishing is what removes the wax/sealant. I would imagine most people (on this forum at least) aren't applying a coating unless they do at least a light polish first.
 
Here's something I've noticed over the years:
A fat person uses more soap than a thin person.


Bob
 
So PiPUK... I got to reading your previous write-up...
Looks like you came to the conclusion that even IPA doesn't remove wax or sealant? If this is true how can we have gone all these years installing coatings over an IPA prepped surface without the coatings failing regularly?

As others have said, one will tend to have removed the lsp during polishing and the IPA removes the oils (such as the kero) that will be left from the polish. I don't believe that IPA is really the ideal product as it does not have any lubrication on its own, thus has potential for marring your beautifully refined finish. I believe it was Mike who convinced me of this.

Another thought is that coatings are not all alike. I have previously commented that some 'coatings' perform little better than some of the more advanced sealants and the safety data provided gives ingredient listings more consistent with a sealant description. Moreover, results with carpro essence seem to indicate that coatings can be used with certain surface contamination present. I have yet to see the safety data sheet but I would be surprised if there were no lubricating oils (for instance) present. Overall, the message is that, just because a product is marketed as a coating does not mean that it is horribly sensitive to anything foreign on the paint. The reverse is also true, just because many coating do work with foreign material, does not mean that they all will. For instance, unless there is safety/compositional information about essence, we can't know what it is leaving behind. Thus you would be fooling to try a coating over it, unless the coating manufacturer confirms it.
 
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