To Wet Sand... or Not to Wet Sand

Ohio Detailing

Ohio Detailing

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Hey guys & girls,

You know - although it's more time and product consuming in the end than anything else... I was wondering if wet-sanding my car would be the answer. I hope not, although 11 years old (97), it's actually quite vibrant. Maybe I should simply compound.

Aside from just my personal car, what is everyone's opinions here on wet-sanding, either site-specific or entire vehicle?
 
Unless you are trying to get rid of lots of scratches, I'd not recommend wet sanding without seeing the vehicle. I just finished a pretty major wetsand operation on a Black BMW and it is definitely time consuming:

1. Paint gauge the car and know there is sufficient paint to work with.
2. I NEVER drop below 2000 grit paper. Most often, I stay with 2500 and finish with 3M Trizact 3000. Dropping to a heavy grit paper is an invitation to disaster!
3. After completing your sanding, you will need to compound with wool or a foam cutting pad and check your work A LOT. The BMW I did required several re-do's of compounding that I missed on the other passes (very frustrating).

After many hours, you will have a flawless vehicle like this: (sorry for the Ultrafina splatter, but I'll be washing and waxing tomorrow)

BMW545i_Ultrafina.jpg


BMW545i_Ultrafina2.jpg


Good luck with your decision

Toto
 
Thanks a lot Totoland. That really helps... I think I'll end up spot sanding at most, but 90% I'll only use a heavy cut compound, and go through that process... I don't feel like spending another 10 hour day in my garage, both my wife and I work 2 jobs :(
 
AaronRaySmith said:
... but 90% I'll only use a heavy cut compound, and go through that process...
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At the expense of asking wrong question (as I haven't checked all of your posts to see whether you have posted pictures of what you want to address) may I ask what about your car makes you conclude it is heavy cut compound that you should be doing?
 
ZoranC said:
At the expense of asking wrong question (as I haven't checked all of your posts to see whether you have posted pictures of what you want to address) may I ask what about your car makes you conclude it is heavy cut compound that you should be doing?
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Well, there are heavy (overt in the light at right angle) horizontal scratches on the clear coat door panels, from someone taking their fingers and a dirty terry cloth towel, and buffing off wax last week from side to side at a less-than-prestigious detail shop.

I still haven't taken pictures, recent ones at least since then, because both my wife and I work two jobs. From 10 feet away after the clay, polish, and wax - the paint looks stunning, but get closer in a flourescent light, and you can see tiny 4-6 inch scratches on the clear coat surface on almost every panel of the vehicle.
 
AaronRaySmith said:
Well, there are heavy (overt in the light at right angle) horizontal scratches on the clear coat door panels, from someone taking their fingers and a dirty terry cloth towel, and buffing off wax last week from side to side at a less-than-prestigious detail shop.

I still haven't taken pictures, recent ones at least since then, because both my wife and I work two jobs. From 10 feet away after the clay, polish, and wax - the paint looks stunning, but get closer in a flourescent light, and you can see tiny 4-6 inch scratches on the clear coat surface on almost every panel of the vehicle.
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Good description! And, you made your case for just compounding. Usually, wet sanding is reserved for deeper scratches (ones you can feel with your fingernail). Putting wetsanding in perspective: Wetsanding is an abrasive method of leveling the area surrounding the scratch. Compounding does the same thing only slower. With wetsanding you lower the chance of rotary paint burning because you have abraded the surface before using the rotary and the rotary will only need to remove the sanding dullness. Therein is the challenge of wetsanding! Removing the sanding marks and dullness is definitely a challenge! I inspected a Black BMW 4 different times and thought I finished out the car. After glazing (which amplifies the surface), I found a few areas I missed...that's 4 separate inspections in proper indoor lighting as well as 2 times in bright sunlight. Talk about frustration!

Wetsanding is appropriate for isolated scratches and in the case of the BMW, the sanding was extensive: i.e. entire door panels, etc. I really got an education on this car. Wetsand, compound, remove dust with ONR, glaze, inspect and make corrections BEFORE moving on to the next panel. This was a 4 day paint correction!

Toto
 
WOW... ok, I am never going to utter the words 'wet sanding' again - EVER. Haaaa! :)

Hey bro, thanks a lot for your help.
 
AaronRaySmith said:
WOW... ok, I am never going to utter the words 'wet sanding' again - EVER. Haaaa! :)

Hey bro, thanks a lot for your help.
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Not a problem at all Aaron! BTW, I hope I have 1/10th the energy of Jack LaLane as I get older....what a discipline!

Take care and have a great day.

Toto
 
I know that subconcious reaction to hearing word "scratches" is "compound". But let's first make sure scratches are really scratches and not something lesser. Starting with least aggressive method first (at least sight unseen) might be erring with advice on side of caution, but it is safe.
 
You know, this is some of the most sound advice I've gotten (along with the other awesome help here on AG) because I tend to always go with more is better methodology of detailing and life in general.

I should start with a light cut, and then med-heavy, and so on, until I can differentiate the true deep scratches from the surface blemishes. Is that correct? Is it safe to go over my car with 3 coats of varying compounds in a single day to wash out the major scratches from the surface ones?

ZoranC said:
I know that subconcious reaction to hearing word "scratches" is "compound". But let's first make sure scratches are really scratches and not something lesser. Starting with least aggressive method first (at least sight unseen) might be erring with advice on side of caution, but it is safe.
Click to expand...
 
And, let's not forget: it's also pressure + pads + product. One of my shortcomings the dealer points out is: I'd rather use light pressure and make multiple passes rather than heavy pressure and take a chance on the paint (but heck, I'm old...what did he expect?) LOL.

Pressure is really an unknown unlike pads and product. Too bad there's not a pressure gauge on the top of machines. What a nice combo that would make: Use Pad X with Product Y at 20Lbs of pressure.

Toto
 
A couple of things, although i would agree with Toto on grit, I have used 1500 and followed up with 2000 grit using Presta cutting creme and then Menz final polish with flawless results. A word of caution like Toto said, this should only be done if you know the depth and are very skilled in paint refinishing. There is a lot of literature out there that states you show always start with the least abrasive polish, if that doesn't work than try a pad with more cut and the same polish. Then work your way into compounds.
 
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