damp/wet sanding questions

[dnoraker]

I just got an '03 Suburban in "Indigo Blue". Beautiful truck! I'm looking to bring it near show-truck-grade using some damp/wet sanding. I have all the 1500 and 3000 discs for 3" and 6" DA and all grades of wet papers from 2000-3000.

My last vehicle was an '05 Pacifica in Magnesium Pearl (green-ish) and I damp sanded almost the whole thing because the orange peel was almost unbearable. The doors, though they weren't repainted, had even worse peel than the rest of the car. I ended up using the 3" DA with 1500 on those to level the paint, then it took 2-3 laps (sometimes more around near (taped) edges) with M105 and the double-sided wool pad to clear the sanding marks. These panels sanded nearly flat and have awesome reflections; I sanded until there was very little glossy paint left in the "craters". On other panels, I tried 2000 wet papers and wasn't trying to get it completely flat and the reflections are a lot better than factory, but not as clear as the 1500 grit areas. All in all, that car looks amazing and I get a lot of compliments from people who know what Chrysler paint looks like. Here's the catch- I didn't work with a depth gauge and so I'm not sure if I took too much clear off. Because the paint is a pearl metallic, it's not a real glossy paint in the first place, so I thought the car looked a little murky anyway. But, it made me wonder if I had taken enough clear off where it didn't have as much depth of gloss.

Now on to the truck. Yesterday, I did this with the hood:
- damp sanded with the 6" DA and 3000 grit discs (4-5 overlapping passes, medium arm speed)
- M105/rotary/Megs double-sided wool, which got most of the sanding marks out
- same, but with purple Kompressor pad, which knocked out the rest of the sanding marks
- M205/rotary/orange kompressor
- 85RD/rotary/blue to give it the finishing touch

This process seemed to reduce a little bit of peel, and get rid of most of the texture in the paint that looks like a paint spray mist (like micro-orange peel). DOI has increased (though wasn't bad before), and I can clearly read road signs in my hoad while driving!

Now, the rest of the truck seems to have more peel to it and I'm undecided on what to do. I want this truck to look smoking hot, as it's the first vehicle where I don't see myself selling for a long time (we are about to have 3 kids and might want 4-5 total). The body is nearly perfect, even with 110k, and worth putting the time in.

Do I:
- continue my process, which my have little effect on a couple panels that seem to have worse peel
- maybe try running the 3000 grit longer for more peel reduction, though this hasn't seemed to help a lot on on my Pacifica
- add another step before with 2000 or 2500 by hand since I can't find DA discs for the in-between grits
- go for the gold and start with 1500 and sand it nearly flat for the best DOI

Another Question:
- those of you with damp sanding experience, do you follow 1500 with 3000, or just go straight to compounding? I've tried it both ways on my Pacifica and I'm not sure if I saw a difference. MAYBE slightly better reflections where I followed with 3000, but I might be seeing things.
- do the 3" discs wear out after a panel like a door? I think I've used even 2 3" 1500 discs on a door. I don't think I'm moving too slow (I can't move too fast without losing accuracy), and I think I'm using enough water, but I can't tell for sure.
- If I sanded the paint on my Pacifica to where I saw only isolated "glossy" areas in the craters, then 2-3 laps with M105 and an aggressive wool pad, would you suspect that removed too much paint?

 

[dnoraker]

After 3000 grit, M105, M205, 85RD:

 

[dnoraker]

Update:

I will be doing a full-bore sanding of the truck, going through 1500-2000-2500-3000 and maybe 4000 before buffing. I will finish with Opti-Coat to seal it all in and give it extra UV protection.

I hope to do a full write-up with a lot of pics. I hope to be done by the end of January, as I have to pick at it a little at a time.

 

[marsomthing]

Any updates? Curious to see if you smoothed out the other panels...the hood looks great

 

[marsomthing]

Nevermind just saw your last post...my bad

 

[Mike PhillipsMike Phillips is verified member.]

Now, the rest of the truck seems to have more peel to it and I'm undecided on what to do. I want this truck to look smoking hot, as it's the first vehicle where I don't see myself selling for a long time (we are about to have 3 kids and might want 4-5 total). The body is nearly perfect, even with 110k, and worth putting the time in.

Do I:
- continue my process, which my have little effect on a couple panels that seem to have worse peel
- maybe try running the 3000 grit longer for more peel reduction, though this hasn't seemed to help a lot on on my Pacifica
- add another step before with 2000 or 2500 by hand since I can't find DA discs for the in-between grits
- go for the gold and start with 1500 and sand it nearly flat for the best DOI

If this is the factory thin paint... I cannot share enough the sinking feeling you will get when you're buffing along and your turn your pad over and see blue paint on it.

Keep in mind,

Sanding removes paint
Compounding removes paint
Polishing removes a little paint

And it's after all of the above that you run the risk of having a whoops happen...

One thing you can try is to use the #3000 grit without the foam interface, this will increase the leveling power of the lighter grit disc.

You could hit it with something more aggressive but then you'll want to re-sand with the less aggressive paper and the compound and polish and again, it's a very sinking feeling when you go through the clear.

Maybe I missed it but if this is custom paint and you know the painter sprayed extra clear than go for it just move carfully...

Another Question:
- those of you with damp sanding experience, do you follow 1500 with 3000, or just go straight to compounding?

I always finish out using the highest grit paper or disc I have available. It usually means it will be faster and easier to removing your sanding marks via compounding and it will also reduce buffing time which means less exposure to the paint to heat.

- do the 3" discs wear out after a panel like a door?

Yes. One thing you can try to check for wear is sand a fresh area and it will be pretty easy to see if you're disc is still cutting or worn out.

- If I sanded the paint on my Pacifica to where I saw only isolated "glossy" areas in the craters, then 2-3 laps with M105 and an aggressive wool pad, would you suspect that removed too much paint?

Couldn't be any worse than some guy named Bubba chopping on any car detail using a RB with a wool cutting pad and any caveman compound...

The thing to remember is all of the UV protection for the basecoat is in the clearcoat, so the more clear you remove the less UV you have. Dr. G told me that the UV protection in the factory clear layer of paint has a half life and degrades over time so even what you start with doesn't protect as well down the road let along if you've removed some...


Try to balance what you want, (show car finish), with practicality of "keeping" this rig and not re-painting it.

 

[dnoraker]

I'm meeting with Rasky on Saturday morning to do some PTG readings. He and I have been talking a lot about this project and about my last project I worked on (Pacifica, which I recently sold). I have read about a lot of the risks and have been warned by Rasky as well about the potential pitfalls. He's planning on coming over later in Jan. to help apply some Opti-Coat after I'm done with the sanding/buffing.

Here's the way I'm looking at it- The truck has some major car wash scratches (which are probably at least as deep as 1500 grit sanding scratches) and to remove these, I would have to do a couple laps with a wool pad and M105 to get it 99% swirl-free. I would have a very shiny truck but the orange peel is still pretty nasty. I figure if I replace that compounding step with sanding, I can get rid of most of the peel while I remove scratches.

I know that if I get overly D.O. and get it completely flat, I might be asking for trouble on a daily driver with three young kids around that could potentially scratch or ding it and then I have no way of safely buffing out the scratches. I guess I'm looking for the middle ground where I can smooth it out substantially and leave myself the ability to compound out a scratch down the road if needed. I'm willing to take the risk to get the truck looking near-show-quality.

I have done a little work on the lower door panels and it turned out real nice. Here is what I did:

- 1500 Megs Unigrit via 3" PC to reduce the peaks enough where I saw maybe 30-50% "shiny paint" visible around the peaks.
- 2000 by hand to even that out and hopefully reduce the remaining peaks to where there was very little shiny paint visible
- 2500 Mirka Abranet via 3" PC to remove the 2000 sanding marks
- 3000 and 4000 via PC to smooth it out and reduce buffing time later
- M105 via rotary and 3" backing plate and wool pad. 1 lap for the most part; a second lap where I missed some spots. Not much heat on the paint, as I tried to go lighter on the pressure.
- M205 with LC orange 3"
- 85RD with LC white 3"

There is still a little waviness visible, but the car wash scratches are gone and the paint is very glossy and clear. I found it difficult to evenly sand the area with 1500 on a 3" on this panel so I'm going to do this by hand on the similar panels, and maybe even just generally so I can work a little slower and precisely.

One thing I learned from Rasky is to keep the speed down on the DA. I was ruining sanding discs left and right on my Pacifica with the speed typically on 5. Now I'm using speed 3 and I swear it's cutting easier and I haven't wrecked a disk yet.

At the end of the day, if I blow it and burn through or have some clear failure a few years down the road, a buddy of mine has a paint booth at his house and has been painting cars for years.

 

[Mike PhillipsMike Phillips is verified member.]

I'm meeting with Rasky on Saturday morning to do some PTG readings. He and I have been talking a lot about this project and about my last project I worked on (Pacifica, which I recently sold).

If you're working with Chad then you're in good hands!


:xyxthumbs:

 

[dnoraker]

Orange peel and crazy car wash scratches:

Lots of scuffs:

After 1500 (trying to cut down majority of the peaks:

After 2000 (trying to get nearly flat by hand):

After 2500:

After 3000:

After 4000:

After M105 and M205:

Done:

 

[dnoraker]

If you're working with Chad then you're in good hands!


:xyxthumbs:

He has been awesome and willing to help along the way and has expected nothing in return. I hope to return the favor and assist him on a project sometime just for the experience. :dblthumb2:

As you can see in the pics, the peel was greatly reduced. It doesn't show quite as much in the side to side because I didn't sand as much near the edge, but it's a pretty shocking difference.

There are areas on the truck that aren't bad and won't take this aggressive of an approach, but there are other areas (unfortunately the hardest ones like the pillars) that are very rough. This was above average peel on the truck, but not the worst by any means.

 

[dnoraker]

Below is another reason why I wanted to sand my truck. I hand sanded nearly flat my wife's uncle's Solstice last year and the results were pretty stunning. I believe it's the same color as my truck. I actually sought out this color of Suburban because of the Solstice.

 

[shoeless89]

Your hood looks STUNNING! I have yet to try much damp/wet sanding besides in isolated areas. You give me hope!

 

[dnoraker]

Your hood looks STUNNING! I have yet to try much damp/wet sanding besides in isolated areas. You give me hope!

Well, don't get TOO much hope because I'm not an expert and could be ruining my truck as we speak. :buffing: Seriously, it's very difficult to remove 1500 and 2000 grit sanding marks on factory clear and easy to get in over your head. I'm currently taking a break from doing the lower part of the driver door on the Suburban because I'm getting frustrated that I got too far along with the finer grits and didn't realize that I never totally removed the 1500 scratches and they're not buffing out with M105. Grrrr. I have about 2 hours into 4 sq ft and probably have another hour to go to get it right, including removing the rogue sanding marks and polishing it out and getting a temporary LSP on until I get the Opti-Coat applied.

3000 and 4000 grit damp sanding isn't that hard if you're competent with a DA. Common sense goes a long way, too. 3000 grit seems to smooth the texture a bit, improving the reflections, but doesn't seem to remove as much paint as, say, M105 and a wool pad. The coarser grits do a better job of leveling the paint and not just glancing over the peel, but it's just very difficult to remove the sanding scratches.

 

[Ted S.]

Can't wait to hear the results you get this Saturday. I don't have a PTG, but I wetsand certain things. It can be scary stuff.rops:

 

[dnoraker]

3am and I'm finally finished with the bottom of the drivers door. 4 hours. Next time I will make sure I totally remove the 1500 grit sanding marks thoroughly before I move on.

First pic is after an IPA wipedown after all buffing was done. Last one is after Fuzion.

It looks totally sick. I can't wait to get this beast done. The metal flake is insane.

 

[Ted S.]

Very nice progress. I just hope the factory paint wasn't too thin to begin with.:xyxthumbs:

 

[dnoraker]

Very nice progress. I just hope the factory paint wasn't too thin to begin with.:xyxthumbs:

Me too, but I'll find out tomorrow about how much I actually removed with the paint depth gauge readings. I'm not too worried.

 

[Mike PhillipsMike Phillips is verified member.]

Properly polisehd clearcoated metallic finishes look amazing!

Nice work so far!


:dblthumb2:

 

[dnoraker]

Had a great time hanging with Rasky (Chad) at his shop yesterday morning. We took some PTG readings and talked shop for a couple hours. My brain is nuked, but I have some good ideas for making some improvements to quality and speed of my work.

PTG ratings were favorable. The areas I sanded and buffed were within a safe range. I only removed about 10 microns, or about .4 mils.

We figured out two areas that had been repainted, one of which had a thinner area. One seemed to have some body filler. Still, the readings were safe enough to proceed with sanding the entire truck, using a similar method to what I started with.

I'm going to acquire a firmer block for the flatter panels to see if I can get a smoother reflection, though what I'm getting isn't bad. My plan is to continue using 1500 by hand to take the peaks down, finish removing the peel with the 2000 by hand, refine with 2500, 3000, 4000.

With the buffing side of things, I need to make sure I actually remove all prior sanding marks as I step down so I can do

LC orange and M105
LC orange and M205
LC blue 85RD

I've had to use wool to get the paint clear because I wasn't quite getting scratches out on each successive step. I'm having a frustrating time figuring out how long the sanding discs are actually effective. The Meguiars/Nikken 3000 discs seem to go for awhile, but the Mirka Abranet 2500 doesn't seem to go far at all.

Hopefully I can get some things ordered and get cracking again in 5-6 days. I will post results!

 

[rockinrandall]

That 'Burb is gonna be the best on the block for sure! It's really looking fantastic. My wife cracks up every time I look at these forums. I see your work and get all geeked up to do her car. She does like the fact that she benefits from my cleaning passion. I haven't been brave enough to venture into wet sanding. Seeing your pics though, I may have to dive in.