Redoing the wax job?

Spring is coming soon. I will be clay barring, and putting down sealant and wax.
What is the best/safest chemical to clean off last year's protective coatings?
A friend said to use isopropyl alchohol.

Wash with dish soap then the alcohol.

What is the "protective coating" from last year? If you applied wax and sealant a year ago it's most likely gone by now. The act of claying the vehicle will also remove most sealant/wax. You can buy a shampoo designed to strip the vehicle, add a small amount of all purpose cleaner to your wash bucket or foam gun, or wipe down with diluted IPA

The sealant could still be on depending on which product was used. To fully remove the previous coatings, I wash with normal car soap and dry, then use a 3:1 ratio of water to isopropyl alcohol in a spray bottle. Spray liberally onto one panel at a time and wipe dry with a microfiber towel. Once you're done, everything is nice and clean to lay a coat of sealant or wax on.

One way to tell if protection is still on the car is pour water on it. If it beads then it's still protected, if not then most likely it's ran its course. Also I have yet to see any sealants/wax last for a year. I'm not saying I've used all of them, but the ones I've tried personally, none last a year lol. As mentioned above, stripping soap and/or 3:1 ISO alcohol should remove it. If you have a DA polisher, polishing paint removes protection.

Clay bar with a heavy spritz of dish soap and water in a spray bottle as lubricant will do the trick...no need for anything else.

Cleaning with dawn soap, and then using soapy dawn water as lubricant during the clay bar should do the trick. Unless this is a special hardened sealant we are talking about.

I use Dawn dishwashing soap.

Bankss550 said:

One way to tell if protection is still on the car is pour water on it. If it beads then it's still protected, if not then most likely it's ran its course. Also I have yet to see any sealants/wax last for a year. I'm not saying I've used all of them, but the ones I've tried personally, none last a year lol. As mentioned above, stripping soap and/or 3:1 ISO alcohol should remove it. If you have a DA polisher, polishing paint removes protection.

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This is inaccurate because there are many other factors which could cause water to bead, as it is a function of surface tension. A perfectly polished surface will bead water, as will a poorly polished surface with left over polish residue and oils. That isn't a one-size-fits-all test.

PatrickGT said:

This is inaccurate because there are many other factors which could cause water to bead, as it is a function of surface tension. A perfectly polished surface will bead water, as will a poorly polished surface with left over polish residue and oils. That isn't a one-size-fits-all test.

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What is a good test on a polished surface?

I am wondering if I need to do my car again. The car has been parked in the garage since November and hasn't spend a whole lot of time outside since then. When I bought the car last July I had it clay barred and a sealant applied (Mequiar's 21). At that time the water would not bead. Lately it has been in the rain a couple of times while watching football with friends in the garage and it beads up.

What gives?

PatrickGT said:

This is inaccurate because there are many other factors which could cause water to bead, as it is a function of surface tension. A perfectly polished surface will bead water, as will a poorly polished surface with left over polish residue and oils. That isn't a one-size-fits-all test.

Click to expand...

http://www.incrediblydetailed.com/when-your-car-needs-waxed/

I guess we will have to disagree. I speak from personal experience. Polish only has never beaded any water for me. I have 2 friends that detail for a living who also agree. No one said anything about a one size fit all test.