P21S Gel - actually spray-on, rinse-off

**Radarryan** · 09-22-2013, 12:37 AM

I know, I know. It's hard to believe but the title is true. I've been testing out a lot of wheel cleaners lately, with an emphasis on color changing, iron dissolving wheel cleaners like SONAX Full Effect, 1Z Colourtech, Griot's HD, etc.

Each wheel received a different cleaner. I, out of habit, agitated each of them, but when I got to the P21S I decided to see how it did without agitation. I did the first wheel with the SONAX, then on the second sprayed the P21S, then allowed it to sit while I did the other two. I then came back to the dwelling wheel and hit it with a strong stream (not power washer) of water from the hose. To my surprise, and astonishment, all the grime, brake dust and dirt came right off. Now, they weren't too dirty, but still a nice layer of filth.

I'm thinking that this will be my go-to wheel cleaner, especially since it appears to work as a spray and wash with no agitation needed. I'll still probably keep the SONAX or 1Z around for periodic cleanings with the wheel woolies and Daytona brushes, but I'm glad I took her out of retirement today. All the obsession with color-changing made me forget. Also, you can't beat how gentle it is on the wheel - always a plus. Only downside is the price. Even in bulk it's steep.

I look forward to hearing other's experience and thoughts/comments.

As always, happy detailing!

**Setec Astronomy** · 09-22-2013, 05:23 AM

That's not a fair test unless you use the other wheel cleaners with a soak-strong stream-no agitation method. My experience with P21S is that it won't take off anything that's stuck on without agitation (of course that is my experience with Sonax as well) so you may be surprised how this works with your other cleaners.

**Desertnate** · 09-26-2013, 09:59 AM

Originally Posted by Setec Astronomy

That's not a fair test unless you use the other wheel cleaners with a soak-strong stream-no agitation method. My experience with P21S is that it won't take off anything that's stuck on without agitation (of course that is my experience with Sonax as well) so you may be surprised how this works with your other cleaners.

My experience with both P21S regular wheel cleaner and the gel spray was the same. When using it on two-week old BMW brake dust, it didn't do much and I still had to hit the wheels with the brush. I found the soap from my wash bucket work as well, if not better.

**Radarryan** · 09-26-2013, 11:12 PM

Originally Posted by Desertnate

My experience with both P21S regular wheel cleaner and the gel spray was the same. When using it on two-week old BMW brake dust, it didn't do much and I still had to hit the wheels with the brush. I found the soap from my wash bucket work as well, if not better.

That was my experience with P21S as well, that's why it stayed in the back of the detailing cabinet and I went off on the iron-disolving tangent. The difference this time was I left the Gel on for a much longer time (it says it can be left on for up to two hours) and then when I rinsed off with a strong stream of water the brake dust went right off.

The initial test were on Aston Martin wheels, which are high performance like the BMW. My mom has an X5, so I'll give it a shot on hers and see if I can replicate the results. Next up is on my 911, and it's German as well so it should pose a good test. I will be sure to post back when I have the results.

**Desertnate** · 09-27-2013, 09:19 AM

Originally Posted by Radarryan

The initial test were on Aston Martin wheels, which are high performance like the BMW. My mom has an X5, so I'll give it a shot on hers and see if I can replicate the results. Next up is on my 911, and it's German as well so it should pose a good test. I will be sure to post back when I have the results.

I'll be interested to see your results. I'd be shocked if the pads for the Porsche and the BMW didn't come from the same vendor (if OEM) or at least have a similar composition. Heavy break dust seems to be a German performance car trait. Audi, BMW, and Porsche all seem to suffer it on OEM pads.

**Radarryan** · 10-17-2013, 05:38 PM

Well, I've finally completed the test with my Porsche brake dust. Let me say, I am not impressed with the results with the spray on, dwell, spray off results of the P21S Gel. The brake dust has been accumulating for about a month - so it is very heavy (all in the name of testing. I normally would never allow it to go more than a week or two without a complete wash).

My process was: spray on moderate heaviness on all four wheel faces and barrels; dwell for approximately one hour; rinse off with heavy stream of non-pressure washer water. The thick brake dust (maybe even some road tar mixed in) in the barrel was not effectively cleaned with this approach. Quick agitation of the dirty areas produced satisfactory results that were able to rinse clean within seconds, but not spray and rinse.

Now, a couple reasons why this could have been the case. First, it is harder to get even, complete coverage from just spraying the barrel, which means that these extra dirty areas did not have a chance to be loosened by the wheel cleaner. Next, the dirty areas could have been composed of road tar, which I do not think the P21S is made for. While the agitation allowed for complete and thorough cleaning, it is possible that the application of a tar remover with the P21S in these areas would have changed the result.

The face of the wheels produced satisfactory results with just the spray-dwell-rinse approach. Again, more complete coverage was achieved because of the nature of the spray. Also, the brake dust accumulation was noticeably less on the face than the barrel.

So, what do I think? Well, I think that I will continue to use the P21S on light-to-moderately dirty wheels. I think that with this level of dirt, I would still be able to use the wheel cleaner in the spray-dwell-rinse manner. For anything heavier, I think I will go with an iron-dissolving wheel cleaner (SONAX FE, 1Z Colourtec) that requires agitation. I think that these wheel cleaners would provide a better cleaning when agitated than the P21S when agitated.

Now the downside is the price. For the price, do you really want to spend for something that, realistically replaces soap and water (at least for lightly soiled wheels)? I cannot answer that question as everyone's goals are different. For me, for example, I would probably be willing to purchase it because it saves me from having to agitate most of the time. As a crazy enthusiast, I don't have to worry about the bottom line and making a profit because my only constraint is how much time it takes to wash and/or detail my car. I am willing to pay a premium in order to lessen the time it takes me and lessen the effort that I have to put in.

So there you have it. I have now seen that for heavily soiled wheels, P21S Gel is not a spray on, rinse off wheel cleaner. Even the benefit of a long dwell does not totally alleviate the shortcomings of the product. Do I still think it is a good product? Yes. Have I been proven wrong? Yes. Am I still impressed with the product? Maybe. Will I continue to use it? Time will tell. I'll have to post my next few receipts.

I welcome any questions/comments.

Happy detailing!

**af90** · 10-17-2013, 06:04 PM

1z colourtec has been my favorite so far, excluding trying p21s gel, but against sonax and poorboy's spray and rinse (which eats sprayers) I found the foaming in colourtec much better and requires less product.

**ScottB** · 10-17-2013, 06:21 PM

I have found agitation is best with any wheel cleaner, even the color changing versions. The most important ingredient is a cool wheel, never clean hot wheels.

**melF1fan** · 10-17-2013, 07:07 PM

I want to try Colourtec out soon. After Sonax / Griot's / Adams' / Wolf's, Iron-X is the best even spray on, hose of on dirty caked BMW wheels. Without going the almost too strong wheel cleaners. I've wanted to try P21S Gel but already have Chemical Guy's Diablo gel and think they may be too similar.

**Radarryan** · 10-17-2013, 09:36 PM

Originally Posted by melF1fan

I want to try Colourtec out soon. After Sonax / Griot's / Adams' / Wolf's, Iron-X is the best even spray on, hose of on dirty caked BMW wheels. Without going the almost too strong wheel cleaners. I've wanted to try P21S Gel but already have Chemical Guy's Diablo gel and think they may be too similar.

I have Griot's HD, SONAX FE, 1Z Colourtec, P21S Gel, and CG Diablo all sitting in my detailing cabinet. I think that P21S is probably a better cleaner, but with agitation Diablo is pretty good. When you take into account the price of Diablo it is sure tough to beat.