Wet vs. dry sand?

[Sidney Schwartz]

I don't use water when sanding. I find that I'm constantly having to wipe away the water to check the progress of the sanding. You can see on the roof the finish I'm typically able to get this way. Am I really going to see any significant improvement by wet sanding, or any improvement at all?

[ctruss53]

I'm not sure the results are any different on way over the other. But I find my paper goes a lot further when I wet sand.

[Ace-Garageguy]

Water is primarily to keep the abrasive from "loading up" or clogging with material that's been sanded off.

It also acts as a lubricant, allowing you to use less pressure while sanding, and both functions make the abrasive last longer.

As long as you're happy with your results, there's no particular other benefit to wet-sanding.

[Dpate]

I generally dry sand everything except when it comes to clear coat.  I always wet sand especially when going higher grits, and it doesn't take a lot of water.  To much water can actually hinder sanding performance for example micro mesh using to much water can work against itself, and i would never use that type of sandpaper dry always wet.  But if you're getting the results you want dry sanding than do just that - because there's no set in stone rule that you have to wet sand.  It's all just preference like how you're using novus and i use meguiars ultimate compound.

Edited March 16, 2023 by Dpate

[Bainford]

I find I get much better ‘feel’ by wet sanding. I am much better able to ‘read’ the surface I’m working, feel the paint being worked, and to what degree I’m removing material. Part of the reason is the sanding medium is not loading up as you work, constantly changing the feel of the sanding medium against the surface. Sanding wet, the feel remains consistent throughout the work, only changing gradually as the surface loses roughness. That way what you feel is the surface, not the sanding medium. I dip the sanding pad frequently, keeping the surface flooded to maintain that consistency of feel. Yes, lots of wiping the surface to check progress. Sometimes every few swipes, when getting close to the mark. Wet sanding also gives you more overall control over the rate of material removal, very important when colour sanding, and allows you to remove material faster with less effort by just cranking up the pressure a bit, while at the same time allowing your sanding pads to last longer. 
 

Find your sanding zen. 

Edited March 16, 2023 by Bainford

[Mike C]

When you wet sand it's also good to add a little bit of soap to the water for better lubrication.

[R. Thorne]

Wet sanding creates much less dust to breathe and scatter on the work bench (especially important with resin parts).  Most of the debris ends up in the water bowl you’re using to dip the sandpaper in.  The sandpaper doesn’t clog as easily (hence, lasts longer).  To me, the surface is smoother, too, and you get a better feel of what you are working on.  I don’t see any disadvantage to wet sanding.

[StevenGuthmiller]

I guess that you could say that I use a "damp" sanding approach. 

 

Like the OP, I don't feel like I can adequately see my progress as I sand with wet sanding, so I'll generally start with a lightly damp sanding pad, (I use Micro-Mesh pads) and then throughout the sanding process, I'll periodically wipe the pad on a cloth, followed by swiping the portion of the pad that I'm using over my tongue to keep it lightly damp.

Probably not the most hygienic method, but it works well for me. 

 

I do agree that wet sanding will preserve your sand paper longer, but the pads that I use seem to wear about the same no matter if they're wet or dry, so I prefer them "almost" dry.

I seem to get pretty good results.

 

 

 

Steve

[Ace-Garageguy]

1 hour ago, StevenGuthmiller said:

...I seem to get pretty good results.

Understatement of the week.

[Mike C]

Mr. Clean's Magic Eraser is good to use too. It's seems to be equivalent to the 4,000 grit emery cloths we use for polishing the models. You can buy this stuff as a "no name" from Amazon for much less money. like this: 

[Bill Eh?]

1 hour ago, Mike C said:

Mr. Clean's Magic Eraser is good to use too. It's seems to be equivalent to the 4,000 grit emery cloths we use for polishing the models. You can buy this stuff as a "no name" fro

Michael, I have purchased a bulk bundle of those melamine cleaning sponges. It never occurred to me that I could also use those as a high grit sanding medium. Thanks for that idea.

[Ace-Garageguy]

Here's an FYI about wet sanding I learned from doing many many real cars:

Every time you change to a finer grit sandpaper, wash out your water container (if you use one), get fresh clean water, and wash the model too.

The reason is that abrasive particles will come off the sandpaper and get suspended in the water to a certain extent, or stay on the surface of the paint.

You don't want to be trying to get a 1500 grit surface finish with any loose 180 grit particles in your water.

I've had "inexplicable" scratches appear miraculously in an almost ready-to-polish surface because a couple of course abrasive particles got under my ultra-fine sandpaper.

You're welcome.  

NOTE: It's obviously not as much of a problem if you're using a hose or squirt bottle on a real car (which should still be washed between successively finer grits), but modelers tend to use an open container of water and dip the paper in it (at least, I do).

I used to use an open bucket for wet sanding real cars, to conserve water, which is how I became aware of where deep scratches were coming from when I thought I was almost finished.

Once I started changing the water, and washing both the bucket and the car between grits, no more problem.

 

 

Edited March 16, 2023 by Ace-Garageguy

[Sidney Schwartz]

Wow, many Words on sanding. ? I appreciate all the suggestions. What I'm doing doesn't seem to be broke, so I won't try and fix it. There are always more questions, though. A couple of things I haven't quite figured out yet...

1. When sanding, what do you do about areas like those indicated in the pic? Try to sand all the tiny spots, or just not bother?

2. What do you do to keep from sanding the paint off edges and raised bits?