Need advice to remove 2000 grit sanding marks

[Roan65]

I’m new to polishing and probably a little to ambitious. I decided to wet sand my custom painted ram 3500 quad cab long bed truck. I started with 2000 grit on my porter cable. I tried using 6 inch, but just wasn’t getting good rotation. So I did most of it in 3 inch...that’s a lot or real estate to cover. I then followed up with 3000. Now I am using a DeWalt rotary and a wool cutting pad with Meguiars m100 to compound. I’m having a heck of a time getting the sanding marks out. Usually taking 4- 6 tries. I’m moving the machine slightly faster than I would an orbital in roughly a 2x2 making about 6 section passes. I’ve watched several videos and read posts about rotarys and I feel I’m getting the hang of it, but open to any pointers.

I am getting wore out going over the same section multiple times.... I’ve also tried Meguiars 105, with similar results, but like 100 better. I just switched to 3m advanced rubbing compound and I think it works better for removing the scratches, but definitely more dusty and certainly doesn’t finish as nice. Im running low on the 3m and thought about trying a different product?

Any tips or advice, or just suck it up and keep using m100?

 

[Mike PhillipsMike Phillips is verified member.]

Wow!

Hats off to you for tackling such an arduous project. Especially if you've never wetsanded before.


Here's your truck in full size

It sounds like you're doing everything right.

Machine wetsand - finishing out at #3000 grit.

Cutting with a rotary buffer, wool pad and M100 - great compound by the way


But you're saying your NOT getting the sanding marks out 100%?


Assuming you're using good technique while running the buffer the only other thing that comes to mind is potentially very hard paint?

I wish I could be there to do a Test Spot for you and dial in your process. Where are you located?

 

[Roan65]

Thanks Mike for resizing my photo. Feel like a road trip? I’m in Alaska.

I’m having a hard time getting 100% removal, I’m seeing a few pig tails. After my posting I gave it more thought. I did about 6-7 section passes with 3000 maybe I should do another 5-6 before compounding. Also the sanding discs I used weren’t the best quality, that might be where the pig tails came from. I’m sure I need to improve my technique as well.

 

[MrRoo]

After doing tons of sanding, I’ve found that the type/quality of sandpaper makes a huge difference. We use the Rupes dry sanding system now. Have gone away from wet sanding. When we get pig tails it’s usually from dirt in the sanding paper. Reason we switched to the dry sanding setup. Much less pigtails. I have awesome results with CarPro Clear Cut. We also use a lot of Sonax Cut Max. Both cut and finish great. I like the clear cut for its better and quicker finish. I’ve used a ton of Megs 105 also with great results besides the dust.


Sent from my iPhone using Tapatalk

 

[Roan65]

Thanks mrRoo. I think you are correct. I went over an area again with 3000 grit. Made another 6 section passes then compounded with the 3m then followed by M100. That did the trick. I will play around and most likely the m100 should do it. The next time I will use higher quality sanding discs.

 

[fightnews]

Never done it but try maguiars new compound and do 12x12" sections at a time

 

[Mike PhillipsMike Phillips is verified member.]

Also the sanding discs I used weren’t the best quality, that might be where the pig tails came from.

What brand of discs are you using?

 

[tomsteve]

machine sanding is nice but nothing beats wet sanding by hand. i can hear when there is a piece of grit between the sandpaper and surface,stop, and not make too much of a mess to correct.. when wet sanding by machine, its best to use a sander with the smallest orbit- larger orbit machines tend to cause pigtails. i dont use an orbital until the last grit if i chose to use one.
what RPM are you running the rotary at?
it somewhat reads like you may not have enough product on the pad or not enough rpm's on the rotary.

 

[Roan65]

UPDATE:

I'm making progress! I tried Sonax CutMax, and twisted wool pad on the rotary at 1600 RPM, and have had good success. It's taking out the pigtails usually on the first try and leaving a nice shine. However, the Cutmax is leaving some pretty good swirl marks and i'm having a heck of a time getting 100% scratch removal even after following up with the DA. The grey hides them pretty well, but the black shows up.

On my Porter Cable I have tried multiple pad combos with Megs 205, and Wolfgang total swirl remover 3.0. I'm having the best luck with the Wolfgang on an orange pad at a 5 setting on the PC, but it's still not perfect (90-95% removal). My last step is Cquartz UK coating, and I'm trying to be a perfectionist and achieve 100% if possible. Should I try a differant product, or keep trying to perfect my technique (on a DA I believe I have decent technique)? OR, its just a truck and live with 90% removal and instead, get the boat ready to take to the lake?

Those who do this professionally, My hat is off to you!!! There is truly an art to this. I must say my rotary technique is getting better and that has helped.

 

[Mike PhillipsMike Phillips is verified member.]

UPDATE:

I'm making progress! I tried Sonax CutMax, and twisted wool pad on the rotary at 1600 RPM, and have had good success. It's taking out the pigtails usually on the first try and leaving a nice shine. However, the Cutmax is leaving some pretty good swirl marks and i'm having a heck of a time getting 100% scratch removal even after following up with the DA. The grey hides them pretty well, but the black shows up.

Are you pushing hard on the rotary?

If you feel the CutMax between your fingers there's nothing to feel. It feels like Jergens Hand Lotion. No grit particles.

So the swirls you're seeing are more likely from the individual fibers that make up a wool pad. These fibers are a form of abrasive. If you push hard, (normal for cutting), you push the fibers into the paint and they leave a deeper swirl.

If you clean the wool pad and the re-buff using CutMax and LIGHT pressure you will remove the deep swirls and replace them with shallow swirls and these will buff our faster and easier.

On my Porter Cable I have tried multiple pad combos with Megs 205, and Wolfgang total swirl remover 3.0. I'm having the best luck with the Wolfgang on an orange pad at a 5 setting on the PC,

That's too low of a setting. You must use the 6.0 setting on the PC as it's one of the weakest polishers on the market.

Also - mark your backing plate. The pad MUST ROTATE in order to remove paint and level the surface.

Video: Mark your backing plate to make it easy to see pad rotation

 

[Roan65]

Great info, thank you, Mike! Yes, I am pushing hard, so that makes sense it is the fibers of the wool pad. I guess The boat has to wait...

 

[Dr Oldz]

Just to add: lighten up your pressure towards the end of the buffing cycle with the wool pad. You can use CutMax and a cutting Foam pad after the wool and it should give you the clarity to see if you left any sanding marks.