Wet-Sanding Process

[Bwiser]

Hey Everyone,

One of my friends car got keyed last night and while the damage is not good, it could of been a whole lot worse. Most of the scratches are deep enough not to be able to polish them out completely, but they did improve and most of lesser degree scratches came out beautifully. I also filled the scratches in with some factory touch up paint to help out. So I'm currently planning on wet-sanding the rest of the deeper scratches out. However, I'm new to the whole wet-sanding procedure/process and was wondering what products I need from start to finish? What grit selection? What pad selections for removal? wool first or foam with M105?...then what?
I'm more worried about the overall sanding/compounding/polishing process to get the sanding marks out by using the correct products and proper steps. I have already watched the wet-sanding videos, but still very confused on the process. I'm experienced in using the rotary polisher and the DA polisher. Any help will be greatly appreicated.

Thank you!

[Bwiser]

Re: Wet-Sanding Process

I was wondering can W5000 be subsituted with a similar pad like (solo system) WWHC7 or WWLC7 pad with M105? Out of these two which one is recommended to use?

[Mike Phillips]

Re: Wet-Sanding Process

I was wondering can W5000 be substitute with a similar pad like (solo system) WWHC7 or WWLC7 pad with M105? Out of these two which one is recommended to use?

Yes. The M105 can be used with any of our Wool pads.

However, I'm new to the whole wet-sanding procedure/process and was wondering what products I need from start to finish?

What grit selection?
What pad selections for removal? wool first or foam with M105?...

then what?

From experience, sanding touch-up paint flat with the surface is easy enough to do, you but when you go to buff out your sanding marks the rotating buffing pad and chemical combination will tend to pull the touch up paint off the car. You can try, just don't buff the area too long and heat the paint up and that will help a little.

Another option would be to do it all by hand. Sand the touch-up paint flat using #2000 grit paper, if possible re-sand and finish with a higher grit, as high as grit as you can get.

Then take some M105 and foam applicator pad and rub your sanding marks out by hand. This will take a few applications but can be done. Be careful you don't rub to hard and fast as you can actually generate quite a bit of heat when you exert a lot of pressure to a small area with fast rubbing action.

You might be able to get the finish nice enough to go straight to wax after the M105

You could also try using a DA Polisher with the M105 and a cutting pad. This is not a Meguiar's recommended procedure because it using a cutting pad on a DA Polisher can tend to dull the finish down but if this happens you can go over the area again and use a less aggressive product and pad to remove any hazing. By using a DA Polisher you can still build up some heat but not as much pulling power like a rotary.

Touch-up paint application, sanding and buffing to a high gloss is usually very tricky and you can make it as complicated as you want and in some cases do more harm then good.

Here's 2 very important tips.

1) Let the touch-up paint completely dry before sanding and buffing, as in let it dry for a days, even a week or so in the sun. You want it fully cured and dried before you work on it.

2) Try to limit you sanding marks to just the touch-up paint as best as you can

Best of luck to you...

[Bwiser]

Re: Wet-Sanding Process

Thanks Mike for the reply!

Yeah, I'm definately going to let the touch up paint dry rock hard before going at it with wet-sand paper and the rotary polisher. I have a few more questions. What is a good starter unigrit to begin with? How many do I need of each? (I know this question depends on many variables, but what is the average life spand of a sheet of unigrit. I'm just trying to get a ball park life-span for I know how many to buy). Also, what is a good combo/selection of different grades to complete most common problems like this and the alike? when would you need a paper like 1000 or 1500?

Also, if I'm using the rotary polisher I can use either a wool pad or foam cutting pad? or is it recommended to use just the wool pad in the beginning and then start using a polishing pad afterwards with something like M82 or lesser if necessary and top it off with wax? Also, what wool pad is recommended for removal of sanding marks, WWHC7 or WWLC7?

Thanks again!

[Mike Phillips]

Re: Wet-Sanding Process

What is a good starter Unigrit to begin with? How many do I need of each? (I know this question depends on many variables, but what is the average life span of a sheet of Unigrit.

This is just a recommendation based upon my own experience you can take it for what it's worth. For you tool chest or arsenal of products, having a sleeve of the following will enable you to tackle jut about anything that comes your way, these are all the Nikken brand Finishing Papers.

#1500
#2000
#2500

Our Nikken #1500 cuts as fast as a generic #1500 grit wet/dry due to the 100% even coverage over the entire face of the sheet of paper so you can get the same cutting power as #1000 grit without instilling the deeper scratches and tracers associated with #1000 grit papers.

#1500 for initial cut, #2000 for a second cut to remove the #1500 grit sanding marks and #2500 for your finishing cut to make buff-out faster and easier with less risk of overheating the paint. (Shorter buffing cycle).

#3000 is is less aggressive but in most cases unnecessary if you have #2500 as a quality compound with a wool pad on a rotary buffer should remove #2500 as long as the paint is still in a window of time after spraying that it hasn't fully set-up or hardened. If you're working on fully cured or hardened paint then finishing with higher grits by machine is a best case scenario like the 3M Trizact #3000 or the Mirka Abralon #4000 grit sanding disks. If working all by hand then I can't say I've personally found finishing with #3000 grit versus #2500 grit to make much of a difference because it's usually going to be difficult no matter which paper you finish with.

It makes sense on paper, (no pun intended), that removing #3000 grit sanding marks will be easier than removing #2500 grit sanding marks but from personal experience if the paint is baked on hard, then with either grit it's going to require some effort to remove hand sanding marks 100% completely, (not just make the surface shiny) Other's can feel free to chime in if they're experience is different, at some point each person has to develop their own system. I would choose machine sanding over hand sanding any day when possible.

Also, if I'm using the rotary polisher I can use either a wool pad or foam cutting pad? or is it recommended to use just the wool pad in the beginning and then start using a polishing pad afterwards with something like M82 or lesser if necessary and top it off with wax? Also, what wool pad is recommended for removal of sanding marks, WWHC7 or WWLC7?

Thanks again!

You can use a foam cutting pad instead of a wool cutting pad if you want to but a wool pad is going to cut the sanding marks out faster and easier than a foam cutting pad with typically less heat build-up.

With M105 you can cut with wool and then do your follow up or secondary buffing step with a foam polishing pad and a cleaner/polish and even better a foam polishing pad and M205 when it becomes available.