Wet and dry sanding-Whats the benefits of each one?

[pampos]

I am going to remove the OP from my car soon and i am wondering which method it is better to use and why..

Can anyone help me on that please??

[qwertydude]

Wet sanding is the only way to go for op, dry sand and the paper will clog really fast. Dry sand is for prepping a surface for painting by using a rough grit which won`t clog.

[ABQDetailer]

This isn`t factory paint is it?

[pampos]

i just repaint my car a week ago...what if i will use 2000 grit for dry sanding??

[Flashtime]

2000 wont level much. Try 1500 then 2000. Better yet 1000 -> 1500 -> 2000 -> 3000+.

As you`re sanding, use a spray bottle with a little soap for lubrication.

[Flashtime]

That quarter panel can be started with either 1500 or 2000. The bumper cover,

(lower left of pic) can be started with 1000. You`re looking at about 15/20 hours of

sanding...

[the other pc]

I much prefer dry sanding to wet sanding for removing op.



Dry sanding goes a lot quicker because you can inspect your progress constantly. You don’t have to wipe down the surface and wait for it to dry to see the results.



You can only dry sand with abrasives that are specifically designed for dry use. Some automotive abrasives are for wet only.



The best way to sand (dry or wet) is with a short throw pneumatic DA.



Wet sanding actually cuts faster than dry but you’re slowed down by having to always dry off the surface to inspect it.



The finest cut generally comes from wet only abrasives with foam backing or foam intermediate pads.



So, cutting op dry (with something like #1200 or #1500) and removing the scratch from that cut with finer wet abrasives (#2000 and/or finer) before buffing leaves an excellent finish with less work.





PC.

[Flashtime]

Well, i doubt pampos with be sanding down peel like this on a regular basis.

So, with just a few packs of paper and some elbow grease, he can do a fine

job. And wipe downs with a squeegee is quick enough. But doing this on a

regular basis is something else...

[the other pc]

Wiping may not take very long, but neither does sanding a small to moderate area.



Let’s say there’s six seconds of messing with water for every thirty seconds of work. That’s 20% of the total job. (Maybe not an exact number, but from my experience it’s about right.)



That means that a job that would take twenty hours to do wet will take sixteen to do dry. And since you bought dry abrasives (or better yet, wet or dry abrasives) instead of just wet ones for the heavy cut it didn’t cost you any extra.



You get back four hours of work for free and results that are just as good.





PC.

[Flashtime]

Not disagreeing with at all, but if pampos doesn`t mind investing in a DA

and a compressor to run it than why not?

[David Fermani]

For OP removal, I prefer sanding wet via DA with 1200/1500. I`ve always just squeegied away the water to gauge the removal/finish. Doing it dry makes too much of a mess IMHO.

[pampos]

Thanks guys!!I have a DA (UDM)....The problem is that i cannot find sandpapers for the DA more than 800 grits in Local market so i bought 3M wet& dry sand 1200, 1500 and 2000 grits for doing it with hand....

While i was preparing the car for the painter,i notice that with dry sanding it was easier to check the results instead of wet sanding....The painter told my that the reason that using the wet sanding method it was just for the dust to go away from the car,so it will not caused problems during painting the car..

I know that each guy has his own preferred method to do it but is there is something in general that says which method is better??

Also i guess that with dry sanding there is no reason to scare if you are removing too much clear because you can check easier the process...The OP has peaks and low areas if i am not wrong, so removing the OP means that i have to level the peaks to the low areas level?? By leveling the peaks that means that i don`t really remove too much clear,right??

Thanks again guys!!!!

ps If you know, from where i can order some sand papers with a foam from the UDM??

[JohnKleven]

When I`m sanding to remove orange peel on a new paint job I usually start with 1000 grit dry on a DA. I then go to 1500 grit dry on a da. I then usually block the car wet with 2000 grit to remove any squiggly marks left behind by the d.a. Sometimes I`ll finish with trizact 3000 which makes for really easy polishing when the sanding is done. If you have access to a DA and a compressor it saves a lot of time. The thing that usually takes the most time is polishing the car afterwards.





John

[pampos]

When I`m sanding to remove orange peel on a new paint job I usually start with 1000 grit dry on a DA. I then go to 1500 grit dry on a da. I then usually block the car wet with 2000 grit to remove any squiggly marks left behind by the d.a. Sometimes I`ll finish with trizact 3000 which makes for really easy polishing when the sanding is done. If you have access to a DA and a compressor it saves a lot of time. The thing that usually takes the most time is polishing the car afterwards.





John

I have the UDM DA polisher...Is that OK to use this or not??

[the other pc]

... I`ve always just squeegied away the water to gauge the removal/finish. Doing it dry makes too much of a mess IMHO.

Fair enough. I guess it depends on which sort of mess you prefer, a wet one or a dusty one.



If I were doing it all the time I’d see about picking up a DA with dust-vac, less work and no mess.

I have the UDM DA polisher...Is that OK to use this or not??

Sorry, I wouldn’t recommend it.



As I mentioned earlier, it‘s best to sand with a “short throw pneumatic DA� because they’re designed for finish sanding. Electric DA’s have large orbits and remove too much material too fast. I’d think there`s too much risk of plowing all the way through the paint.



If you’re stuck doing it by hand, be sure to use (foam) sanding blocks/pads. Sanding with your fingers produces very uneven pressure and an inconsistent cut that’ll be more work to buff out.





PC.