What are your thoughts on wet sanding factory paint?

**z06meister** · 03-01-2010, 07:17 PM

What are your thoughts on wet sanding factory paint? I know it can be done but you need to be very careful since factory cc is very thin yada yada yada.

What I am interested in discussing is... Do you think all the protection and/or UV protection is in the outer most layer?

I have talked to a few body men painters including my brother who is a painter for a living and he has also gone to a few classes and talked to a few paint reps and they all say that if you do not have to break the outer shell of the paint, hence, wet sand you should not do it because this outer layer has the most protection in it and the car will be more susceptible to bird bombs, acid rain etching and possibly even fading. Most will say if it is a garage queen or show car you are usually OK.

What are your thoughts?

I have done quite a few cars and have never had a problem or seen any type of cc failure due to this but do suspect that there is some truth to what the painters are saying.

Of course on repaints where the painter is expecting to cut the paint in order to provide a 100% smooth finish they usually lay down extra cc which is fine. It is the factory paint that is questionable.

There is also a company in Calif that does nothing but this, I am sure some of you have heard of them, glossycar. It seems they have no issues either.

A painting forum would probably be a better place for this discussion but I do not know of any.

**A4 1.8tqm** · 03-01-2010, 07:33 PM

Well I'll state the inevitable, you need a paint thickness gauge. I want one but can't justify the cost. I don't have tons of experience with wet sanding factory CC but am in the middle of fixing a DIYers terrible paint work which was laid on nice and thick.

I really don't know about the claim of "the outer layer has more protection" it just doesn't seem logical. Maybe you'll lose some protection because the coat as a whole it's thinner but not cause you lost the magic top most layer. lol IDK though.

Mike Phillips · 03-01-2010, 07:36 PM

Originally Posted by z06meister

There is also a company in Calif that does nothing but this, I am sure some of you have heard of them, glossycar. It seems they have no issues either.

I know who you're talking about, I can't think of his name but he's attended one of my classes in the past, I've seen his work it's phenomenal and he's done a great job of lighting his garage for his work. Here's his website, Corky is his name.

GlossyCar.com

I just went there and noticed he has a plug for the detailing classes I brought up and taught at Meguiar's, maybe he'll give us a plug out here on the East Coast?

I'm in the camp of more paint is better but this would start at the factory level, that means I wish car manufactures would put more clear on the car instead of "just enough" clear on their cars.

I was actually in a meeting with to very high-up representatives from two European car manufactures and in the meeting they actually bragged how they were working on new methods of paint cars that would actually reduce the amount of paint needed to coat a car.

I sat in this meeting and when I heard the one man say this I couldn't believe what I was hearing, I could tell the guy had no clue as to the frustration with think paint that detailers and even car owners have to deal with.

Clueless.

I'd say the thin paint and hard paint are in the top 5 list of the worst things about modern paint technology, swirls would be on the top of the list too, but thin and hard would be my 2 top issues.

**z06meister** · 03-01-2010, 07:41 PM

Originally Posted by A4 1.8tqm

Well I'll state the inevitable, you need a paint thickness gauge. I want one but can't justify the cost. I don't have tons of experience with wet sanding factory CC but am in the middle of fixing a DIYers terrible paint work which was laid on nice and thick.

I really don't know about the claim of "the outer layer has more protection" it just doesn't seem logical. Maybe you'll lose some protection because the coat as a whole it's thinner but not cause you lost the magic top most layer. lol IDK though.

Yes, a paint depth gauge is nice but when you work mostly with fiberglass cars they really are out of the question unless you got 2g to throw away on one. Common sense also goes a long way when doing this type of work.

My big question is this magic top layer these paint reps tell me about. Obviously if you remove 25% of the CC you would have 25% less protection. Paint reps try to tell me you are losing a LOT more than that by cutting the hard factory paints outer crust.

I have done many cars and seen even more than I have done and have never seen an issue. That said most of what I have seen have lived a charmed life.

Here is a pic of what I usually do. Actually, I will usually not even go this far and leave some peel remaining to be on the safe side. It still looks 1000 times better than before it was cut.

Yes, that is the guy Mike. Unfortunately the car companies only think about one thing, their bottom line.

Just to give you an example the XLR's all come through with beautiful paint and little to no OP. The vette's have terrible OP on the sides. This is because the corvette line does not have the room to lay all the panels horizontally so they hang them vertically to save space, the paint is not able to flow as nice and you end up with OP.

**forrest@mothers** · 03-02-2010, 09:09 AM

Originally Posted by z06meister

I have done many cars and seen even more than I have done and have never seen an issue. That said most of what I have seen have lived a charmed life.

Any damage from removing too much clear or the UV protection in the top of the clear won't become apparent until some time down the road - less on a vehicle kept outside, but a longer time on one that stays garaged.

Wet sand a daily driver that sits outside 24/7 and take a look at it in 2-3 years. That will tell you if claims that the UV is in the top layer is accurate or not.

Personally, I wouldn't wet sand a new vehicle - it's asking for trouble.

**ScottB** · 03-02-2010, 09:18 AM

If needed, I would consult a professional.

**SwedenDetail** · 03-02-2010, 09:08 PM

A new 3000 grit wetsand disc will cut 4 microns of the paint the first lap it makes on the paint and then less and less. There should be little worries sanding a factory paint if necessary that is.

**expdetailing** · 11-09-2015, 03:17 PM

I wet sanded a portion of the hood and driver's door on my vehicle and then measured the thickness. Although I don't remember the numbers, I do know that the sanded areas were measuring thicker than many non-sanded areas.

Mike Phillips · 11-09-2015, 03:29 PM

Originally Posted by expdetailing

I wet sanded a portion of the hood and driver's door on my vehicle and then measured the thickness. Although I don't remember the numbers, I do know that the sanded areas were measuring thicker than many non-sanded areas.

The only way I see that to be possible would be if the area you sanded and then measured was still warm or hot from the process and thus the paint swelled or expanded.

Or the above happened, that is the paint swelled or expanded due to friction/heat and then after cooling down for some reason did not at the same time 100 percent contract to it's former shape/thickness.

Simply because if you abrade paint off the surface it doesn't make common sens that the paint would be thicker in that area but instead thinner.