how aggressive is wetsanding?

III

97 bonneville/98 Z71
Is wetsanding the most aggressive way to remove swirls or defects from paint? For example, would wetsanding be more aggressive than using meguiar's diamond cut compound using a wool pad?
 
Wet sanding is only for professionals, or someone with big $$ to mess around and tinker with this hobby.



Wet sanding is more abrasive than anything like diamond cut, or any other product.



If i were to guess, i would say after 2000, 4000 wet sand paper, something like diamond cut is more like 8000 wetsand paper, and then something like DACP is probably around 20,000 grit wetsand paper.



If such a comparison could be made....due to diminishing abrasicves, DACP probably breaks down to 100,000 or more grit paper.
 
LouisanaJeeper said:
both sound pretty agressive if your talking about a rotary



how big of an area are we talking about?



Yes, I'm talking about using diamond cut with a rotary. The area would be the hood of a vehicle. By no means would I attempt to wetsand a vehicle. Heck, I don't even have any experience with a rotary yet. I'm asking this question because someone I know has been telling me I should wetsand to remove scratches. I told them from what I've seen and heard you only want to wetsand as a last resort. (like if someone has water spots that are etched into the clearcoat, and polishing won't help) I told him that wetsanding would take off more clear compared to using DACP or SSR2.5. In my opinion, people can get by with using a moderate polish like DACP, SSR2.5 or even SSR3 just fine without wetsanding. Anyhow, this made me curious as to just how aggressive wetsanding really is?
 
The flip side of wetsanding is that you're doing it by hand - its easier to control. I do a fair amount of sanding with 1500 and 2000 grit on paint transfer, etc, as I feel its quicker and more controlled than buffing the area. The sanding marks come out fine with powergloss via cyclo, and I've never burned through the clear in 15-20 tries. Just use a lot of soapy water, stick with 2000 grit, use a sanding block, and use no more than 5 light passes.



It's done wonders for me, and I'd much rather sand than use a rotary + wool pad (to be honest, wool pads scare me slightly, cause I've seen the damage they can do in the wrong hands firsthand), but to each his own.
 
Personally i wetsand scratches. I think it is a better approuch than trying to remove them with heavy compound and rotary. The reason is that with a little practice you know how much clear you have removed without heat compared to the rotary.



If you watch the clear when sanding it shows you when the orange peel (dare i say thank god for OP) is almost gone and then you can polish it out, with the rotary and be certain that you have some left. If you tried the pad and compound way you might overheat the paint or cut too much.



After wetsanding the goal is to remove the marring with a fine cut and then final polishing. Which is fairly mild.



I have wet sanded through the clear before ( basicly asked to) and still polished out the marring without any further harm.
 
There are fine grades of sandpaper all the way up to about 12,000! They ought to be sufficiently safe and yeah, it's nice you quite a bit of control over the pressure and passes you make with it not to mention all the areas you can get at unlike with polishes.



From what I've seen, the stuff higher than 3000 grit can be tough to find. The most readily available source I'm aware of ,and I still would need to get from myself, is micromark.com
 
Wow, I didn't know that some people prefer to wetsand over using a rotary with an abrasive polish. This is interesting, keep the comments coming.
 
Well, if nothing more, the least aggressive wet sanding might be an option in locations where a polisher simply can't reach even with a 4" pad.
 
if 3m fine cut claims to remove 1200 grit sanding marks isn't that a fairly aggressive compound-at least initially? I understand that it will break down to a finer product- so wouldn't a 3000 grit wetsand be less aggressive?
 
I've always wanted to find or see someone list an exact # grit sandpaper to compound and polish equivalent table. All I ever see in terms of # grit sandpaper grades in relation to compounds are the types of sandpaper marks the product can remove, not approximately to what # grit sandpaper the product would be similar to. May be just too much of an apples to tangerines comparison :nixweiss
 
Wetsanding to remove marring is definitely extreme. I've heard tell that it will void the warranty from the manufacuter on the finish. I know guys who are more into painting cars than detailing them and they wetsand their brand new cars to get the orange peel out.



For me I'd still rather use a rotary for defect removal. Even with 2000 grit sandpaper your removing more Clear Coat than any polish would.



Without knowing how much clear coat was laid down in the first place, you can and will (if done frequently on the same panel) remove it all.
 
Oh come on now, wet sanding isn't that extreme if done properly. I just did my entire car, and it came out perfect. I didn't make one mistake, and I am quite the clumsy oaf. Just remember to let it soak, use plenty of water, keep the surface from getting saturated in the stuff you remove, and only wet sand till the defect is out.
 
I have bought several grades of paper for wetsanding, the blocks, but I dont have the guts to try it yet, maybe on some wreck of a vehicle.... I have come to the conclusion that wetsanding is a pro tool. I have a video, and it seems like it wouldnt be too hard... but clearcoat is so thin.... maybe after I destroy a couple junkers learning.... Philosophically, wetsanding isnt so big a departure from what we do daily, but I think it is an advanced skill. It is a very aggressive step, IMHO. BTW, is wetsanding the best approach to removing OP? It would seem that the high points would be leveled out.(or can the OP be in the color layer and therfore we remove too much Clear in leveling?):confused:
 
There was (is maybe) a Porsche specialty shop in Southern Ca. near Santa Ana, I use to see his add in a VW magazine. He would do very special 911's and "color sand" finishes. He wrote lots about it and made it sound like no big deal. I asked my bodyshop friend about it and he said clear was so thin he did not know how he did it, so I tucked in my memory banks and never really figured it out. I'll try and find the guys name.
 
Look here --> http://www.sisweb.com/micromesh/.



Do a little homework on wet sanding, and find something to practice on before doing your car (try a spot on your lawn mower, if nothing else).



As stated above by others...



Soak your paper, and make sure it's clean! If you have any grit, dirt, etc on the paper, you'll sand grooves in your paint and they are not fun to get out (I know). I would start off by using 2000 grit or finer. Using something more abrasive than 2000 grit can cut through your clear coat quick. I prefer using a moist poorboys PVA applicator instead of a sanding block.
 
DanoWatt said:
Oh come on now, wet sanding isn't that extreme if done properly. I just did my entire car, and it came out perfect. I didn't make one mistake, and I am quite the clumsy oaf. Just remember to let it soak, use plenty of water, keep the surface from getting saturated in the stuff you remove, and only wet sand till the defect is out.



I was answering the question being asked, which was if wetsanding was an aggressive way remove swirl marks and scratches ?



If you wash your car at least once a week, unless you've got a realllly good system down your bound to get some swirls/scratches. So what are you going to do? wetsand your car every week, that's 48 wetsands a year. There's just not going to be any clear coat left to wetsand.



Even if you did it only twice a year, Spring/Winter full detail, as opposed to polishing, in 3 years that's 6 times you've wetsanded the car.



The point I'm trying to make is wetsanding is for removing defect's from the paint when it was applied. Not for removing marring to the finish after it's cured, that's what compounding and polishing is for.
 
As per a post DavidB started a while back, even regular, semi-aggressive polishing can be a bit much over time. Those of us who keep some vehicle a long time (20 years or more in some cases) have learned to be somewhat conservative about *any* abrasives. There are spots on my Jag that are too thin for further polishing, and I've never used a rotary, or even harsh products, on it.



If you remove defects all the time, you're gonna run out of paint. So be careful with the wash technique ;)



I never use anything coarser than 2.5K and 3k will usually suffice for anything I'm gonna do.



If you take off a lot of clear, at least keep the vehicle out of the sun, especially if it's red or black (the paint will fade without the UV protection of a thick clearcoat). Just because you don't "cut through", that doesn't mean all is well.



A few in-my-experience answers to some of the Qs on this thread:



3M FCRC will really only work on 1200 grit scratches via rotary. But it'll work fine on 2.5-3K ones even by hand.



And it *used* be be that "color sanding" was only for single stage paints. You were "sanding the color coat", back in the day before they topped everything with clear on a regular basis. It was part of the painting process with lacquers, for example.



Yes, sanding is how you remove OP. Note that you'd better do the whole car uniformly or it'll look weird. OP is almost *always* in the clear as the color coat flows smoothly much easier. A painter I know said that "anybody can get the color coat smooth, it's the clear that's tricky".
 
I appreciate the responses so far. It seems like everyone will have an opinion on this subject if wetsanding is extreme or not. I always thought it was, and I still do in my opinion. However, I do agree with Accumulator when he brought up David's point about using semi-aggressive polish over and over on a vehicle. I think the bottom line is whatever we do, whether we wetsand or use an aggressive polish with a rotary, we need to be careful.
 
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