Griot's Garage Paint Prep vs. Polishing?

[rockford33]

So, I have a couple of questions regarding Griot's Garage Paint Prep. I researched some and saw that Mark (07-z-06) used it to strip some Dodo wax he had applied a couple of weeks prior. What wasn't mentioned was if the car was being polished and a new LSP applied, or if he just wanted to try out some other LSP, so stripped off the Dodo.

1. If you plan on polishing the car, do you really need to use the Paint Prep to strip off the old lsp? Won't the polish do that for you? Or will the Paint Prep make it a little easier to polishi since then you are really at the clearcoat without any lsp in the way?

2. About how much of the Paint Prep is required for a mid-size sedan (and does it depend on the lsp cuurently on the car, like Collinite 845)?

3. Will it also strip UTTG? I have that on my exterior trim currently. When I go to polish this fall, if I use the Paint Prep will it strip everything, including my UTTG?

Thanks,
Neil

[The Heater]

Hi, Neil:

I live close to the headquarters for Griot's Garage. Just went to their Garage Sale.

While I am not familiar with using Griot's Paint Prep, I have used a similar product made for the professional body person made by 3M. Here is the deal. If you use an abrasive for whatever you are doing to your paint (like a rubbing or polishing compound), at least if it has some cutting ability of any sort, you don't need to use paint prep unless there are spots on your paint that you can remove with it that don't come off from washing with soap and water.

You can make your own cleaning solution by mixing plain old isopropyl alcohol and water in a 50-50 ratio, put in a spray bottle from your local store, and go around after you wash and dry the vehicle and spritz where there appear to be films on the paint. Wipe off with a clean white towel (to see what is coming off the paint).

The point of using it "all over" the paint is mostly if you were going to apply paint. If you do it, Griot's makes more money because you will buy more of their product. Silicone based waxes have to be removed to get paint to stick. Some other products may not bond to paint that has had a silicone based product previously applied to it. Griot's recommends using it all over the paint to get this stuff off, but honestly, in 40 years of working on car exteriors, I have not run into a problem with putting car care products over previously waxed paint no matter what kind of wax it was. If I wanted to enhance the shine, I get out an orbital polisher, 3M Perfect-It compounds, and all that stuff comes off in 2-3 steps. I clean the areas compounded after each round with the 50-50 isopropyl alcohol-water spray. But that is a LOT of work, and I don't do it to my drivers unless there are a lot of scratches on the panel.

[truckbutt]

I agree with the first part of your response. If you are polishing than a paint prep isn't needed.
The use of IPA as a cleaner wipe down is controversial even at 10:1. IPA can be harmful to paint, especially black. Two alternatives to the Griots are DuPont Prep Sol and Klean Strip Prep All. I use the Klean Strip product. It can be found at Autobody suppliers.
Either of the two products I mentioned will remove UTTG.