wet sanding???

darth_daniel · Post by **darth_daniel** » Wed Jul 18, 2007 5:06 am

Hi,
could anyone please explain to me how wet sanding works and why it is done? Will it produce smoother surfaces? Do I simply apply water to the surface I want to sand? And why does it give different results?
Thanks for any help!

(P.S.: I think someone mentioned it regarding the surface preps he did for his FP Naboo Royal Starship which IÂ´m also working on).

Zen-Builder · Post by **Zen-Builder** » Wed Jul 18, 2007 5:25 am

Wet sanding is a method where you wet suitable sandpaper or sanding sponges(my preferred method).

It helps keeping sanding dust down(important if you work with resin), etc.
In short it helps keep the surface cleaner and thus allows better control.

My preferred method is to keep a bowl of water handy and dip my sanding medium from time to time.

Sanding pads/sponges can be cleaned and dried and thus are reusable, plus they can be cut down to the size/shape needed.
Said that I prefer fabric backed sandpaper vs paper backed sandpaper, way more flexible.

TimeScape · Post by **TimeScape** » Wed Jul 18, 2007 7:56 am

Also, if you buy sandpaper at a hardware or automotive store like I do, be sure you get the stuff that states "wet and dry". Otherwise you get quite a mess.

Kylwell · Post by **Kylwell** » Wed Jul 18, 2007 9:35 am

Wet sanding also helps keep the sandpaper from clogging up, especially in the finer grits (I've got some 10,000 grit that has to be wet sanded).

It's messy but worth the effort. Simply dip your wet/dry sandpaper in water and sand. When the paste gets too bad dip some more.

SpaceDuck · Post by **SpaceDuck** » Wed Jul 18, 2007 10:08 am

Besides keeping the paper from clogging up and offering 'more control' it's meant to float away the sanded particulates which can be more abrasive than the grit of paper itself- so you're letting the paper work and not just regouging the surface and leaving deeper scratches than the actual grit of paper chosen would cause.

But what does it do: You're knocking down surface irregularities (including "orange peel") which reflect light unevenly so that you'll get a smoother, flatter and after buffed/polished- shinier surface. Or in the case of Alclad it gives a mirror smooth base coat over which the Alclad can work best to give that mirror chrome like finish you're striving for. Even if your ultimate goal isn't shine, maybe you'll go over the results carefuly with a final flat coat but nothing screams 'out of scale' like a pebbly (orange peel) paint job on a very tiny model enlarged by photography.

TREKKRIFFIC · Post by **TREKKRIFFIC** » Wed Jul 18, 2007 11:31 am

I like using spit... it stays put and doesn't run all over the place like water. Then again, I also like the gritty texture of plastic dust so never mind...

Lt. Z0mBe · Post by **Lt. Z0mBe** » Wed Jul 18, 2007 9:14 pm

Another very important issue is melting. Melting of plastic during sanding will lead to loss of fine control when sanding. That is, the surface will distort ever so slightly differently than what you expect it to.

Incidentally, I also oftentimes wet file for the same reason.

I hope this helps.

Kenny

Zen-Builder · Post by **Zen-Builder** » Wed Jul 18, 2007 9:20 pm

Actually I often use non-foaming shaving gel for wet-sanding.

A tip I learned from a friend who builds kits professionaly.

Mr. Badwrench · Post by **Mr. Badwrench** » Thu Jul 19, 2007 3:44 am

Often when I have to do a lot of wet sanding, I'll do it in the kitchen sink. Just let a slow trickle of water run over the part while I sand away. Also, wet sanding keeps the sandpaper from wearing out, by quite a lot. I've noticed that wet sanding can increase the life of sandpaper as much as tenfold.

darth_daniel · Post by **darth_daniel** » Fri Jul 20, 2007 1:17 am

Wow thanks guys! YouÂ´re great.

ThatÂ´s a huge load of advice! Gotta try it out soon.

TREKKRIFFIC · Post by **TREKKRIFFIC** » Fri Jul 20, 2007 10:03 am

darth_daniel wrote:Wow thanks guys! YouÂ´re great. ThatÂ´s a huge load of advice! Gotta try it out soon.

Glad to help !

Lt. Z0mBe · Post by **Lt. Z0mBe** » Fri Jul 20, 2007 9:55 pm

darth_daniel wrote:Wow thanks guys! YouÂ´re great. ThatÂ´s a huge load of advice! Gotta try it out soon.

What I do - unless polishing - is just keep a mug of water on the bench and dunk my file or sandpaper in it as needed.

Kenny

big-dog · Post by **big-dog** » Mon Jul 23, 2007 2:27 am

Once you try wet sanding you will hate dry sanding. You will only dry sand when you basolutely have to.

Zen-Builder · Post by **Zen-Builder** » Mon Jul 23, 2007 2:38 am

big-dog wrote:Once you try wet sanding you will hate dry sanding. You will only dry sand when you basolutely have to.

Got to agree here wet-sanding changed my life and never looked back.

Rio · Post by **Rio** » Mon Jul 30, 2007 9:10 am

Staying on this related topic (not to take away from the thread) I am just about to fill all the recessed panel lines on PL's NX-01 in the manly scale, 1/1000.
I have a tube of Tamiya white putty. Is that the best putty in the market for this job?
I also heard Sculpy (sp) might do a better job.
Opinions welcome.
Thanks!!
RiÃ¶<*>
Semper Sci Fi!

Mr. Badwrench · Post by **Mr. Badwrench** » Tue Jul 31, 2007 3:39 am

Don't you have to bake Sculpey? I don't know about Tamiya white, I've never used it. Is it a one part putty, or two part?

Rio · Post by **Rio** » Wed Aug 01, 2007 2:18 am

Tamiya is regular putty. Sculpy, I have no idea.
RiÃ¶<*>
Semper Sci Fi!

Kylwell · Post by **Kylwell** » Wed Aug 01, 2007 9:33 am

YEs, you have to bake Sculpty. I wouln't recoment it for putty work.

The Tamiya white should work admirably. IIRC it's a low shrink, high-tack putty that should work well for such work. I've also used Aves Slip for such things.

"Aves Slip" you ask? I don't see that in thier product line. Well, it's Aves thinned greatly with thier Safety Solution.

Mark Yungblut · Post by **Mark Yungblut** » Wed Aug 01, 2007 10:42 am

For filling I almost exclusively use epoxy putty. When I do use a seam filler I use the bondo finishing putty as it is a lot cheaper than the model stuff and better IMHO.

I do wet sand exclusively and you will find that it creates a finer more "polished" surface when you are done.

Cheers,

Mark

Lt. Z0mBe · Post by **Lt. Z0mBe** » Wed Aug 01, 2007 10:06 pm

Mark Yungblut wrote:For filling I almost exclusively use epoxy putty. When I do use a seam filler I use the bondo finishing putty as it is a lot cheaper than the model stuff and better IMHO.

I do wet sand exclusively and you will find that it creates a finer more "polished" surface when you are done.

Cheers,

Mark

I'd like to add to that. What I do with Bondo - which I only use when I absolutely have to like Mark does - is varnish it with CA glue. I sand it and place a drop of CA glue on the Bondo'd area. Quickly, I rub my finger around the area and coat the area with a thin fim of CA glue. Don't stop moving your finger if possible.

The Bondo soaks up the CA glue. and this does two things:

1.) It keeps the Bondo from shrinking.
2.) It makes it tough enough not to flake and crumble if you need to scribe over it.

As soon as it dries - when smoothed out like this, CA glue takes about ten seconds - sand the area smooth as glass.

Kenny