Wet sanding question

[DownSouth]

A friend of mine is going to repaint the hood of my car. He said he will spray 3 layers of cc, so if there is some op it can be wet sanded out. I have a Flex 3401, LC pfw/yellow/orange/white pads along with M105, SIP, and 106FA.



Will a Flex 3401 struggle to remove wet sanding scratches? Is a rotary necessary?



Also, if M105 can remove 1500 grit scratches, do I really need to sand with anything finer than say 2000 grit?

[gmblack3]

There are at least a few factors that will dictate how easy wetsanding marks polish out:



1. Harness of clear-If you induce deeper sanding scratches into harder clear, a more aggressive polish/pad will be required to remove them.



2. Quality of sanding paper- cheaper paper will induce more deeper sanding scratches that are harder to remove.



I have never used a flex, but from my experience I would never wetsand without the means to remove anything/everything that might pop up.

[DownSouth]

Not sure about the cc harness. I`ll check into that. As far as quality of the sanding paper, I would be using Meguiar`s Unigrit.

[qwertydude]

I`d still go to 2000 with M105. You`ll be polishing longer if you try to work at M105`s limits and you never know if the rougher papers will do some deeper gouging that needs a finer grit to remove.

[UncleWede]

I`ve used 1500 and 2000 on my GMC truck and my neice`s Honda Accord. I had no problem with a flex, LC orange pad, and SIP to remove any marks left by the sanding. It was actually almost scary how easy it buffed out, lending t me thinking I could sand anything I want.

[Xtreme-Klean]

I went through the same situation as yours.

Fresh paint is very soft so it does not take much to cut and buff.

Wait about 1 month for the paint to firm up a bit.

A rotary will certainly give a better quality result.



My process when I sanded my car.

Wet sand with Mirka 2000 grit and finished off with Mirka 2500 grit

Buff with Meguiars M105, 3M Ultrafine

Final buff with PC using a light polish



I wished I started with 2500 grit since I cut out too much orange peel. I was trying to match the OP of the original paint`s OP.

The finish is flat as glass.

[DownSouth]

I`ve used 1500 and 2000 on my GMC truck and my neice`s Honda Accord. I had no problem with a flex, LC orange pad, and SIP to remove any marks left by the sanding. It was actually almost scary how easy it buffed out, lending t me thinking I could sand anything I want.



Cool. I`ll give it a shot then.

[Todd@RUPES]

I must really suck at wetsanding and buffing...



Because everytime I have seen somebody attempt to remove wetsanding marks with a DA it looked like crap. Sure you can bring the shine back, but the paint will usually have a texture to it from a 1/2 an inch away, which looks terrible.



I have met with autopians, including one I argueed with about the possiblity of DAing out wetsanding marks. When I inspected his work in person I thought it looked terrible, there where tracers and heavily textured paint. He thought it looked great.



One thing to keep in mind is that everybody has different opinions of what is `perfect`. To me perfect means no surface texture left over the sanding (even at a half an inch away) and that seems to always require a rotary, full wool pad and a heavy compound.



So either my standards are higher or I just really suck, and I completely open to both possibilities...

[Lumadar]

Well a FLEX isn`t really a true DA... it definitely has the ability to make "rotary only" products work as intended in the vast majority of situations. I have both a 3401 and a Makita and I find in many circumstances I can use them interchangeably. (M105 especially works well on a FLEX).



Either way, with that said if you want to play it safe grab some Unigrit 3,000 and do a final pass with the 3,000. Then, some M105 and a FLEX will have no problem leaving a nice, defect free (in terms of the sanding) finish.

[Flashtime]

Use CLEAN water with a few drops of Dawn dish soap.

Some guys like to sand with running water. A container

with a small hole at the side works great on horizontals.

A spray bottle for verticals.



Finish sanding 2500 plus should make things much easier.

But what grit you start with will depend on the peel.

It`s good that the painter knows enough to shoot 3 coats.



The PFW isn`t very aggressive. 100% twisted wool pad will

make the initial compounding easier going.

[DownSouth]

.....Because everytime I have seen somebody attempt to remove wetsanding marks with a DA it looked like crap. Sure you can bring the shine back, but the paint will usually have a texture to it from a 1/2 an inch away, which looks terrible.

......



Is your opinion based upon the use of a PC only or does that include the 3401 as well?

[wannafbody]

Use Megs unigrit paper. Start with 2000, then 2500 then 3000. I would avoid the 1500.