2000 Unigrit blocks + M105 = ??

[elohel]

I'm attempting to help a sibling with a bad gouge he has on his car. I'm planning on spraying it down with some new paint, then wetsanding that down and polishing it.

I've had bad luck with wetsanding in the past. I believe it was due to me using wetsand paper that you find at walmart, target, etc, and it kept leaving all sorts of tracers behind after buffing it, even with 2500 grit paper.

So, I decided to make the leap to meguiar's sanding blocks as I've heard they're just better. Unfortunately, they're a bit pricey at about $15-17 per block. I decided to just purchase the 1000 grit and 2000 grit blocks as a 3000 grit one was $33

Now, my question is this.. is 2000 grit fine enough to remove the marks with M105 and a DA polisher? I don't have access to a rotary and don't plan on attempting to use one at this point in time.

Thanks for any help!

[ColonelCash]

Re: 2000 Unigrit blocks + M105 = ??

I'm attempting to help a sibling with a bad gouge he has on his car. I'm planning on spraying it down with some new paint, then wetsanding that down and polishing it.

I've had bad luck with wetsanding in the past. I believe it was due to me using wetsand paper that you find at walmart, target, etc, and it kept leaving all sorts of tracers behind after buffing it, even with 2500 grit paper.

So, I decided to make the leap to meguiar's sanding blocks as I've heard they're just better. Unfortunately, they're a bit pricey at about $15-17 per block. I decided to just purchase the 1000 grit and 2000 grit blocks as a 3000 grit one was $33

Now, my question is this.. is 2000 grit fine enough to remove the marks with M105 and a DA polisher? I don't have access to a rotary and don't plan on attempting to use one at this point in time.

Thanks for any help!

I'd be very wary of wetsanding and then turning to a DA to remove the sanding marks. You might want to look to a professional to make the correction, or at least give you some guidance.

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

I've already done this on another car with pretty good results. My only problem was the sandpaper left a lot of random scratches in the paint that I couldn't remove, which I'm attributing to using cheaper sandpaper.

[greg0303]

Re: 2000 Unigrit blocks + M105 = ??

Did you think about using your D/A polisher as a sander? You need backing plate, interface pad and either 3" or 6" finishing discs. You're gonna finish much better with sanding and therefore it's gonna be easier to remove sanding marks.

http://www.autogeekonline.net/forum/wet-sanding-cutting-buffing/26209-meguiar-s-new-3-inch-professional-headlight-spot-repair-kit.html

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

I had not thought about that.. sounds kind of scary using that thing as a sander lol. I'm afraid that might cut too fast and cause damage that I can't fix

[greg0303]

Re: 2000 Unigrit blocks + M105 = ??

I had not thought about that.. sounds kind of scary using that thing as a sander lol. I'm afraid that might cut too fast and cause damage that I can't fix

The arm speed is a key.
I use my G110v2 as a D/A sander with 3" finishing discs for spot repairs. For deep jobs I start with 1000 grit and then follow with 3000. For small repair 3000 grit works fine. I use speed 3-4 and check frequently the progress. I finish much better than if I used wet sanding by hand. Not much water is needed on the disc (as it's called damp sanding) otherwise saturated disc loses its aggressiveness. The biggest advantage is that sanding so even that quick application of M105/ M205 restores clarity in no time.

http://www.autogeekonline.net/forum/wet-sanding-cutting-buffing/25915-damp-sanding-tools-tips-techniques-mike-phillips.html

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

Interesting concept. I would be up for that, but the only problem is that it's a long, thing scratch. I'd say it's about 8 inches long, and only 1-1.5 inches thick, so the 6" backing on the disc would sand a lot more area than I need to. I would go for the 3" kit, but $500 is just too much for what I'm trying to do

[DetailFreak517]

Re: 2000 Unigrit blocks + M105 = ??

Interesting concept. I would be up for that, but the only problem is that it's a long, thing scratch. I'd say it's about 8 inches long, and only 1-1.5 inches thick, so the 6" backing on the disc would sand a lot more area than I need to. I would go for the 3" kit, but $500 is just too much for what I'm trying to do

$500? Not even close! If you've got a DA, all you should need will be (based on Autogeek prices):

S3BP Backing Plate - $22.99
S3FIS Interface Pad - $5.99
S3F1000 Finishing Disc 1000-grit - $44.99 (15 discs)
S3F3000 Finishing Disc 3000-grit - $39.99 (15 discs)

So your total would be $113.96

Also, there are some vendors selling the finishing discs individually so you don't have to spend the coin on a full box if you won't need that many discs. One that comes to mind is ADS -- you might check them out.

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

Gotcha, didn't know you could get the 3" backing for a DA, thought you needed those mini air guns for it. I'll look into it. Thanks!

[greg0303]

Re: 2000 Unigrit blocks + M105 = ??

Your DA polisher can be turned into DA sander. I didn't opt for air tools either because I had to get an air compressor (I think I already have enough tools in my basement). The whole idea here is to make you finish sanding more evenly which will allow you to quickly correct it with M105/ M205. You could start damp-sanding with 3000 finishing disc, just to practice and make sure you don't cut too quickly, and check your progress frequently. I guarantee you that you're gonna like the finish comparing to hand wet-sanding. Big difference.

[Mike Phillips]

Re: 2000 Unigrit blocks + M105 = ??

It would probably be faster to remove the marks by hand first and then do a follow-up by machine, the reason for this is because you can exert a lot of pressure with a couple of fingers to remove enough paint to level the surface. Pushing hard by hand can live some Fingermarks but the machine will remove these.

See these links on the search term exert

http://meguiarsonline.com/forums/tags.php?tag=exert

A DA can remove these kinds of marks but because it has a Free Floating Spindle Assembly, if you push down too hard the pad will quit rotating and thus quit removing paint and thus not remove the marks.

The Free Floating Spindle Assembly - The Story Behind The Story... by Mike Phillips


Same principals here...

How To Remove a Bird Dropping Etching by Hand using M105 Ultra Cut Compound

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

Well, I took the plunge and ordered a 3" backing plate, the foam pad, and 3 of each 1000 and 3000 grit paper disks.

Last question and I'll stop bugging you guys (for now ). How long does each pad last before it should be tossed?

[Michael Stoops]

Re: 2000 Unigrit blocks + M105 = ??

The 1000 grit and 3000 grit finishing discs can cover a lot of ground before needing to be replaced. The finer the grit the less you can tend to work it before it needs replacing. Hard to give an exact number of strokes, or a specific surface area though.

As an example, however, let's say you're doing headlight restoration using these two grits. A single 3" disc of each grit is more than enough to do at least a couple pairs of fairly large headlights, and maybe more.

[elohel]

Re: 2000 Unigrit blocks + M105 = ??

Perfect, thanks. 2 of each disk should be more than enough to get the job done, then.

[mattya802]

Re: 2000 Unigrit blocks + M105 = ??

Let me know how this method worked out for you. I have some small areas I will need to be doing some similar correction on and am also wary about wet-sanding by hand and relying on my DA to remove the sanding marks.