PH in soap

[justacarwash]

I am using a pro brand used by the car dealerships in Northern CA calleed P&S. The P&S soap I use has a 9-10 PH number on their MSDS sheet. I have always read it is good to use a neutral PH soap of 7. What can be the negative side effects of using a PH soap of 9-10?

[Dr Oldz]

Non Ph neutral soaps can strip away your sealant or wax prematurely. They can also dry out rubber and plastics.

[jbgrant]

What is the dilution factor you are using? Like 1 ounce soap in a couple gallons? That would be ~1:250. As long as your water is ground water then it is most likely alkaline and naturally buffered; thus, changes in PH will be resisted to a point. Before you change soaps just get a pool test strip and see if your pH is really much above 8 in the bucket. You most likely don't have anything to worry about unless you're spraying that soap directly on the car. Most soaps are basic in nature.

[justacarwash]

Non Ph neutral soaps can strip away your sealant or wax prematurely. They can also dry out rubber and plastics.

Will a soap with PH 9-10 clean stubbon grime better? It may dry out rubber/plastic but will it have any harmful effects on the painted finish?

[justacarwash]

What is the dilution factor you are using? Like 1 ounce soap in a couple gallons? That would be ~1:250. As long as your water is ground water then it is most likely alkaline and naturally buffered; thus, changes in PH will be resisted to a point. Before you change soaps just get a pool test strip and see if your pH is really much above 8 in the bucket. You most likely don't have anything to worry about unless you're spraying that soap directly on the car. Most soaps are basic in nature.

I use 1 oz of soap to 1 gal of water as per directions.

[jbgrant]

Will a soap with PH 9-10 clean stubbon grime better? It may dry out rubber/plastic but will it have any harmful effects on the painted finish?

There are some very knowledgeable forum members that can give you a better answer, but I would say no you won't do any damage to your paint because the pH in your mixture is going to be <9 and that's not reactive enough to eat (electrochemically reduce) your paint. But, there is a reason you don't use wheel washes on your paint; you can definitely over do it with pH reactivity. Strong acids will oxidize your paint. In general, higher pH soaps are going to free road filth better than neutral soaps.


I use 1 oz of soap to 1 gal of water as per directions.

Okay, so you're diluting your soap by 1:128, so your wash mixture is 0.78 percent concentrated base and 99.2 percent slightly basic water. As I said, as long as this is city well water you are almost certainly fine; however, if you were using distilled or deionized water the pH would be much higher. Rain water would have a low initial pH, but a low ability to buffer the change when adding soap. You really need a 10c test strip (find somebody with a hot tub!).

[Lasthope05]

As jbgrant said, at such a high dilution ratio the overall final product will have a very minimal raise in PH so it should not damage at trim all. Because most wax friendly soaps are around PH 7-9, I would say the soap you are using would be a good strong cleaning soap.

Many people use APCs/degreasers with high alkalinity to remove lsp's on paint and clean rubber seals and trims all the time. The main thing is to not allow the product to dry on the paint as that is when staining can occur, but if kept wet there would be no problems.

[Dr Oldz]

Will a soap with PH 9-10 clean stubbon grime better? It may dry out rubber/plastic but will it have any harmful effects on the painted finish?


There are a lot of other factors in shampoos besides just the ph for cleansing.They contain surfactants for cleansing, gloss enhancers, lubrication, ect. Like the above mentioned about the total dilution and chances are that the water isn't exactly neutral is very true. But considering the layer of protection you are trying to preserve is so thin to begin with it, why chance removing it prematurely by using a non ph neutral shampoo. Many quality shampoos have been designed by experts and they claim ph neutral is the best for your vehicle and I tend to follow their expertise. Hope this helps.

[FUNX650]

I am using a pro brand used by the car dealerships in Northern CA calleed P&S. The P&S soap I use has a 9-10 PH number on their MSDS sheet. I have always read it is good to use a neutral PH soap of 7. What can be the negative side effects of using a PH soap of 9-10?

Do you, or someone you know, work for one of these Northern CA dealerships?

Have these dealerships ever experienced any negative effects on the vehicles that have been washed with this P&S soap?

How about any negative health & safety issues with their employees that have used this P&S soap on vehicles?

Can you obtain these dealerships supplier's name and number for clarification on this PH issue?

Or, I suggest that a call to P&S Chemicals could provide some insight or otherwise be helpful with your questions.

A good chemical company, supplier, or salesperson should, IMO, be willing to explain the make-up, proper usage, health & safety, etc., of their chemicals when so asked.

If you get no relief that is satisfactory to you from these sources; and you still have trepidations about using this P&S soap---IMHO---change your supplier!