The Power of 3000 Grit

[NA Notch]

Re: The Power of 3000 Grit

So if you're really about doing this and decide to just go with, say, 2000 grit by hand, just know that doing so would be roughly the equivalent of using 1000 grit on the DA. Yes, you read that right - hand sanding is that much more aggressive than DA sanding.

I am trying to wrap my head around the above statement. Based on this is it safe to say that using the 3000 unigrit foam pads, with interface and appropriate backing plate is equivalent to 1500 grit hand sanding?

If so I have more questions. My objective is to knock down whole car orange peel from a new paint job. So if the above rule of thumb holds true would I be wasting my time to hand wetsand with 2000 unigrit then move on to damp sand with 3000 unigrit foam pad and G100v2? I ask because I would be smoothing clear with 2000 wet but scratching it deeper wit 3000 damp (equivalent to 1500 sand)? Would I be going in the wrong direction? Or maybe the da with 3000 damp creates a more uniform scratch that cuts up nicer than 1500 hand wetsand? I intend to finish with MF cut and then MF finishing on G110v2. Any help here will be greatly appreciated!!!!!!!1

[jarred767]

NA Notch - Actually, I believe that you might have it backwards. The damp Sanding with the DA is actually less aggressive than doing it by hand. So doing 2000 grit by DA would be similar to doing 3000 by hand. The benefit to using the DA is that the scratches you are creating are WAY more uniform and therefore much easier to buff out, especially using the DAMF system, which it sounds like you are.

So any grit by hand will always be more aggressive than the same grit by DA (assuming your not adding weight and pushing on the DA).

BTW, that is a huge project you are attempting on your car, make sure to not rush it. Good luck with it, and be sure to post some pictures for all of us to see!!

[NA Notch]

Re: The Power of 3000 Grit

NA Notch - Actually, I believe that you might have it backwards. The damp Sanding with the DA is actually less aggressive than doing it by hand. So doing 2000 grit by DA would be similar to doing 3000 by hand. The benefit to using the DA is that the scratches you are creating are WAY more uniform and therefore much easier to buff out, especially using the DAMF system, which it sounds like you are.

So any grit by hand will always be more aggressive than the same grit by DA (assuming your not adding weight and pushing on the DA).

BTW, that is a huge project you are attempting on your car, make sure to not rush it. Good luck with it, and be sure to post some pictures for all of us to see!!

You are right I had it backwards. MS set me straight earlier today. Sorry if I added confusion to the thread. My plan is 2000 wet by hand, 3000 damp with g110, then both compound then finish with the DAMF. So let me ask this: if using 3000 grit 6" foam backed discs with foam interface pad, and proper backing plate what speed should I run the g110 at? Also how many passes at that speed should I be aiming for to achieve a proper surface prior to using the DAMF system? I realize the paint plays a huge role in the answere to that question. I've wetsanded at 2000 by hand and the OP is gone.
(ps. I am posting pics in the "makeover" forum as I make progress)
Thanks for your help!

[jarred767]

Re: The Power of 3000 Grit

I just checked out the thread, it looks like quite a project.

So, let me start saying that I am still very new at damp sanding, but have learned a ton of information at the NXT class over the weekend and am slowly practicing what I learned. Regarding your questions, yes the speed and amount of passes should depend on the paint itself, and basically you want to do the minimum amount of sanding necessary to get rid of any scratches left from the 2000 by hand process. I find that starting at about 3 works nice and then as I'm refining the surface bump it up to 4 or even 5 (but with no pressure at all - in fact almost lifting up on the DA). The higher the speed, the less aggressive it will be (especially with this limited pressure). I would go over it a with a few passes and then then check and see where you're at.

I would suggest doing a test spot with the 3000 followed by D300 and a cutting pad to see if you can achieve the look you want. If you can't get there, then you might have to do a few more passes with the 3000. I hope this helps and I'll be sure to follow the thread you started in the makeover forum.

[NA Notch]

Re: The Power of 3000 Grit

I just checked out the thread, it looks like quite a project.

So, let me start saying that I am still very new at damp sanding, but have learned a ton of information at the NXT class over the weekend and am slowly practicing what I learned. Regarding your questions, yes the speed and amount of passes should depend on the paint itself, and basically you want to do the minimum amount of sanding necessary to get rid of any scratches left from the 2000 by hand process. I find that starting at about 3 works nice and then as I'm refining the surface bump it up to 4 or even 5 (but with no pressure at all - in fact almost lifting up on the DA). The higher the speed, the less aggressive it will be (especially with this limited pressure). I would go over it a with a few passes and then then check and see where you're at.

I would suggest doing a test spot with the 3000 followed by D300 and a cutting pad to see if you can achieve the look you want. If you can't get there, then you might have to do a few more passes with the 3000. I hope this helps and I'll be sure to follow the thread you started in the makeover forum.

Hello Jarred,
Check out my progress. http://www.meguiarsonline.com/forums...Coupe-Makeover

[punkguins]

Re: The Power of 3000 Grit

Okay then! I'll try it.. Thanks Mike for the info!

.

Mike

Wanted your opinion on a rock chip on my front, right wheel well. The rock chip took it down to metal. You can see 2 layers of paint and bare metal. I bought an aftermarket paint kit and after cleaning, applied multiple coats of primer, then, the midcoast and clear coat (it's a 3 color mix). The pea size chip is now "pregnant". If I purchased the 3000 grit, could I effectively smooth the bump out and get it seamless with the original surrounding paint? It's right on the edge of the wheel well so it isn't that noticeable now that paint is on it. I was originally going to wetsand with 3000 grit by hand but this seems better. Thanks!

[drumdan]

I love this idea! The owner of the paint shop I used to patronize recommend that to me years ago. I thought he was nuts!

I'm not sure if you remember, but a little while back I posted my journey on the megs fb page of a Porter Cable 7424xp + Rupes blue microfiber pad + M105 vs. 1000 grit sanding marks.

I wasn't at all expecting the results I got, and it made me question the need for me to use a rotary, or a large throw machine at all.

My theory is that if said combination of tool, pad, and liquid are sufficient for me to remove those defects on that paint, there isn't much I won't be able to handle with just the humble 8mm throw d/a.

It is very rare that I would ever need such an aggressive combination. I once polished out finger nail gouges around a door handle with Ultimate Polish, and a yellow Rupes pad on the PC.

This makes me believe that the d/a machine will be the tool of the future, especially if there would ever be a way to adjust the stroke, as to permit working in tight spots, currently only accessible with a rotary.

[CCC4me]

Re: The Power of 3000 Grit

.

Mike

Wanted your opinion on a rock chip on my front, right wheel well. The rock chip took it down to metal. You can see 2 layers of paint and bare metal. I bought an aftermarket paint kit and after cleaning, applied multiple coats of primer, then, the midcoast and clear coat (it's a 3 color mix). The pea size chip is now "pregnant". If I purchased the 3000 grit, could I effectively smooth the bump out and get it seamless with the original surrounding paint? It's right on the edge of the wheel well so it isn't that noticeable now that paint is on it. I was originally going to wetsand with 3000 grit by hand but this seems better. Thanks!

The foam 3000 discs will conform to the bump and sand the surrounding paint too much. My current favorite way to sand down the touch up bumps is with the 2000 grit sanding block. You can follow up with the 3000 disc to make buffing it out easier, though it's not 100% necessary.

[Michael Stoops]

Re: The Power of 3000 Grit

.

Mike

Wanted your opinion on a rock chip on my front, right wheel well. The rock chip took it down to metal. You can see 2 layers of paint and bare metal. I bought an aftermarket paint kit and after cleaning, applied multiple coats of primer, then, the midcoast and clear coat (it's a 3 color mix). The pea size chip is now "pregnant". If I purchased the 3000 grit, could I effectively smooth the bump out and get it seamless with the original surrounding paint? It's right on the edge of the wheel well so it isn't that noticeable now that paint is on it. I was originally going to wetsand with 3000 grit by hand but this seems better. Thanks!

CCC4me makes an excellent point here:

The foam 3000 discs will conform to the bump and sand the surrounding paint too much. My current favorite way to sand down the touch up bumps is with the 2000 grit sanding block. You can follow up with the 3000 disc to make buffing it out easier, though it's not 100% necessary.

Just as he points out, the 3000 grit finishing disc has that integral foam backer and it will conform to the rise of the "pregnant" paint blob. You want to very effectively level that down, and using either a 2000 grit sanding block, or a piece of 2500 grit sandpaper wrapped over a firm block, works best for this purpose. If you can't locate the sanding block, then take a small piece of dense foam (like our E7200 backing pads) and cut off a piece about an inch square and wrap a small piece of 2500 grit sandpaper around that. Work just that small area of the paint touch up and you'll quickly level down the bump. Don't try using the sandpaper and your thumb, either, as your thumb will also wrap around the paint touchup and you won't level it. 2500 grit sanding marks should buff out very easily with a DA, a microfiber cutting pad and a little M100. Over the holidays I hand sanded the entire rear bumper of my Crossfire with 2500 grit and buffed it out with that combo - piece of cake!

The only concern we have here, however, is exactly where on the edge your chip repair is. If it is, quite literally, on the very edge then you have to consider the potential effect of sanding and buffing right on that edge. Remember, paint tends to be very thin on panel edges due to the way it migrates when sprayed onto the car. You'll need to be extremely cautious with your sanding, paying especially close attention to where that sandpaper might be touching the edge further away from the paint touchup. Keep your sanding stroke very short. That will prevent you cutting too deep on the end of a sanding stroke where you might not be paying as close attention, since most likely you'll be concentrating on the touchup spot itself. We've seen too many first time sanding situations where the operator lost sight of the very immediate surrounding (and, yes, we're talking literally an inch away from the trouble spot!!!) and sanded through to the primer.

[Michael Stoops]

Re: The Power of 3000 Grit

I love this idea! The owner of the paint shop I used to patronize recommend that to me years ago. I thought he was nuts!

I'm not sure if you remember, but a little while back I posted my journey on the megs fb page of a Porter Cable 7424xp + Rupes blue microfiber pad + M105 vs. 1000 grit sanding marks.

I wasn't at all expecting the results I got, and it made me question the need for me to use a rotary, or a large throw machine at all.

My theory is that if said combination of tool, pad, and liquid are sufficient for me to remove those defects on that paint, there isn't much I won't be able to handle with just the humble 8mm throw d/a.

It is very rare that I would ever need such an aggressive combination. I once polished out finger nail gouges around a door handle with Ultimate Polish, and a yellow Rupes pad on the PC.

This makes me believe that the d/a machine will be the tool of the future, especially if there would ever be a way to adjust the stroke, as to permit working in tight spots, currently only accessible with a rotary.

Tall stroke DAs are wonderful, no doubt about it. I happen to love mine, but they do have limitations. A really good shorter stroke tool can do wonders, and anyone looking for such an animal need look new further than our new MT300. We demo'd this tool all week long at SEMA, using the new burgundy foam cutting disc and D300 to remove 3000 grit sanding marks from the very hard Ceramiclear paint on a Mercedes SLS AMG Gullwing. We could have done the job faster using microfiber pads and M100 but A) we wanted to show off the new foam discs, and B) we wanted zero dust in our booth. The foam cutting disc and D300 worked like a charm, and the somewhat slower cut was perfect for the week long demo. Had we used microfiber/M100 we could have buffed out the entire car the first day and would have had nothing to demo the rest of the week!!! That's how effective that new tool can be.

[hgangesh]

Re: The Power of 3000 Grit

Someone was kind enough to scribble with a ball point pen on my car bonnet. Did the fingernail test and does not grip. Tried using ultimate compound and does not come off. Keen to know if wet sanding with the 3000 grit would help remove these fine lines. Even though these are not visible immediately when closely inspected, its visible. Has been a constant eyesore for me and need to get them scratches off. I live in a condo, hence need to do all by hand to keep the noise out.

[Michael Stoops]

Re: The Power of 3000 Grit

Someone was kind enough to scribble with a ball point pen on my car bonnet. Did the fingernail test and does not grip. Tried using ultimate compound and does not come off. Keen to know if wet sanding with the 3000 grit would help remove these fine lines. Even though these are not visible immediately when closely inspected, its visible. Has been a constant eyesore for me and need to get them scratches off. I live in a condo, hence need to do all by hand to keep the noise out.

Wet sanding most likely would remedy your situation, but since you're forced to do this all by hand to eliminate noise, we don't recommend taking this approach. The hand sanding part is all fine and well - if you've done it before and are comfortable with the process, but we don't recommend that you self teach on a car you care about! The problem, however, is the removal of the sanding marks by hand. On modern clear coat that's not going to be an easy task at all. Remember, even 3000 grit sanding will make the paint have a very matte appearance and the only way to bring the gloss back is to buff it out. A good, high powered DA polisher with the right compound and pad (M100 on a microfiber pad tends to work extremely well here) is highly recommended.

[hgangesh]

Re: The Power of 3000 Grit

Thank you all for the support and encouragement.

I do have wet sanding experience, and managed to get rid of the scratches using the 3000 grit. Since the condo is limitation, took the chance during the late afternoon hoping the kids playing along with their screaming and yelling will drown out my Power tool with DA attachment. Bingo, DA and UC worked some magic, swirls and scratches are gone, finished the job off with Ultimate polish and Paste Wax.

[Michael Stoops]

Re: The Power of 3000 Grit

Thank you all for the support and encouragement.

I do have wet sanding experience, and managed to get rid of the scratches using the 3000 grit. Since the condo is limitation, took the chance during the late afternoon hoping the kids playing along with their screaming and yelling will drown out my Power tool with DA attachment. Bingo, DA and UC worked some magic, swirls and scratches are gone, finished the job off with Ultimate polish and Paste Wax.

Success!!!!

[Old Bear]

Re: The Power of 3000 Grit

Mike
With compounding with an electric DA, moving to 3" pad from a 6" is stepping up in aggressiveness.
Assuming the same media, is moving to the 3" sanding disk/media from the 6" sanding disk/media stepping up in aggressiveness?