Clay Bar Necessary when Polishing??
 

Quick question, maybe someone out there can explain to me. But if I were planning on detailing my car using a somewhat abrasive polish, why would I need to do a clay bar first? I mean, I understand that the clay removes things that regular washing cant, but if im goign to be polishing, whats the point? I would imagine the polish would remove what the clay bar removes also....
Im just curious and I am in no way an expert with detailing....

Polishing doesn't remove the stuff stuck to the surface that the a clay bar can remove. The clay bar pics up about 90-95% of the stuff that doesn't belong on your paint. Polishing works basically like sand paper and you want the surface to be as clean as possible to get the best shine. Some polishes will clean some of the those loose particles off, but not nearly as well as a clay bar. You should do the baggie test to see if claying is required. Take a plastic bag, place your hand in between the plastic and run it lightly across the surface of the paint. If you can feel little bumps and debris, a clay bar is required & can take that off. It should come out smoother than glass when you're done.

Using a clay bar when required makes a huge difference. It would be like not sanding before applying paint if you don't.

Agreed. You also don't want to risk something getting stuck between the pad and paint...that could turn into a mess.

I see. Ok, thanks for your input guys...

If you don't clay, then the debris that is left behind is grit that can scratch the poo out of your paint when polishing.

Depending on how much contaminants stuck to the surface I may or may not clay before polish.

This is what i always do before deciding if i need to clay. You don't want to take the chance of any unknown contaminants being on the paint that can stick to the pad as you continue to polish. As an even more cautious step, you can do an IPA wipedown after claying before polishing too, just to ensure the surface is as clean as possible.:tiphat:

Also, the last thing you want is for your pad to be picking up small bits of contamination then grinding them into your paint all over your car, and this can/does happen.

The way I think clay-barring works...

The goal is really to lubricate the surface so it just glides over the smooth areas without really touching the paint, no contact, no scratches. That's what the spray that comes with it is for.

When it runs into a cunck stuck or imbedded in the paint, the contamination will put a scratch on the surface of the clay bar. This action causes the clay to grab and abraid the contamination in a very localized fashion thus removing it from the surface without damaging the surrounding paint. It's really just leveling the area to the point where the clay bar starts gliding over it without contact.

This is good to understand. I have clay at home but have yet to do it myself (had it professionally detailed in October). My biggest worry is to mess up the paint somehow but ive been told that as long as you use plenty of lubrication, it will glide smoothly, like you explained...

If you have never clayed the car before then you need to clay it before polishing. As long as you use plenty of detailing spray while claying the car you will be fine. You won't mess up the paint.

There is a bit of a balance you need to strike... it is possible to OVER lubricate and make the claying less effective. Essentially the ideal scenario is just enough lubrication to allow the clay to slide without catching.

Too much and the clay rides over the top and doesn't make full contact with the contamination, too little and the clay drags which leads to marring.