Dry vs wet sanding acrylics

[bjbear76]

I had ordered some cast blanks that included instructions not to wet sand due to the possibility of moisture getting to the paper on the tube. So I turned a couple blanks last night, dry sanded with abranet followed by MM. I finished one with Novus, the second I buffed with white diamond.
In my opinion, they both came out every bit as good as when I wet sand.
I may try a couple more, but it seems that I can avoid the mess of wet sanding and go this route. Maybe just for clear cast acrylics??
Do any of you strictly dry sand/finish your acrylics? Are there any other pro or cons that I should be aware of?

Thanks,
Bill

 

[nativewooder]

I wet sand unless advised NOT to by the manufacturer.

 

[ed4copies]

The primary reason to wet sand is to keep the heat down. If you dry sand and keep your fingers under the sandpaper, you will know if it gets hot.

I very rarely (a couple times a year perhaps) "wet" a blank. But, I do have the advantage of a buffing system, so I also don't need to use Novus anymore.

 

[sbell111]

I wet sand all acrylics. I seal the ends with CA and have never has an issue.

 

[TonyL]

I dry sand 150 to 600 at less than 400 rpms. It allows me to see if I missed any spots (which turn-out to be deeper scratches if left unsanded). Where ever I don't see white/colored dust, I know that I missed a spot. Then wet sand with MM, by misting MM and blank with a water spray bottle. I like that better than dunking the MM in a reservoir of water. I learned the dry sanding technique from an IAP member's Youtube video and like it.

 

[BSea]

I wet sand. The dust is worse than any mess from wet sanding IMHO. And sbell111 has the right idea on tube cast blanks. I still go light with the water even when sealed with CA.

 

[Turned Around]

I dry sand 150 to 600 at less than 400 rpms. It allows me to see if I missed any spots (which turn-out to be deeper scratches if left unsanded). Where ever I don't see white/colored dust, I know that I missed a spot. Then wet sand with MM, by misting MM and blank with a water spray bottle. I like that better than dunking the MM in a reservoir of water. I learned the dry sanding technique from an IAP member's Youtube video and like it.

+1

I dry sand at first, as well. Helps get rid of any imperfections or chips, then I wet sand. Usually wet sand twice.

 

[Timbo]

I wet sand all acrylics, but seal the ends of the "cast on tube" acrylics with thin CA. I spread a generous amount on the end making sure to cover the boundary between the acrylic and brass tube. Wait 10-15 seconds then dab the excess off on a paper towel...then repeat. I actually do this with all my wood blanks too since I wet sand these also. It eliminated the problems I use to have with the CA finish lifting on the ends of the tube.

 

[edstreet]

The primary reason to wet sand is to keep the heat down. If you dry sand and keep your fingers under the sandpaper, you will know if it gets hot.

I very rarely (a couple times a year perhaps) "wet" a blank. But, I do have the advantage of a buffing system, so I also don't need to use Novus anymore.

I was always told by many in diverse industries the primary reason to wet sand was to flush abraded particles out of the way to reduce scratching, It's more into play with delicate materials and the finer grits as any particle can/will damage the finish and be counter productive to the sanding job. Also in Toji we use heavy amounts of water to do just that, flush out the metal particles and leave a superb patina from the oxidation of metal, mineral and stone.

I had ordered some cast blanks that included instructions not to wet sand due to the possibility of moisture getting to the paper on the tube. So I turned a couple blanks last night, dry sanded with abranet followed by MM. I finished one with Novus, the second I buffed with white diamond.
In my opinion, they both came out every bit as good as when I wet sand.
I may try a couple more, but it seems that I can avoid the mess of wet sanding and go this route. Maybe just for clear cast acrylics??
Do any of you strictly dry sand/finish your acrylics? Are there any other pro or cons that I should be aware of?

Thanks,
Bill

The need to wet sanding with abranet is greatly reduced by the way abranet works. Which is the ejection of particles away from the contact points.

Also MM and Novus? Toss the MM in the trash as Novus #3 removes 800 grit and #2 removes 1,200 grit scratches, it's counter productive to use MM in this case.

Some times, depending in the material, buffing is a very very bad idea.

 

[bjbear76]

Ed, specifically what materials should not be buffed?

 

[edstreet]

Ed, specifically what materials should not be buffed?

Materials that can 'slide' off the tube, i.e. composites, laminate sections like polymer clay, close proximity to stickers, stamps, embeds and the like. The buffer can easily rip them off the tube. The end of the tube is more prone than in the middle obviously, even buffing with bushing on.

 

[DMANTHEROCK]

I never looked into wet sanding. I always have dried sanded. I ussually go 120 grit through 400 grit sand paper. Then I use a a cut off elastic sleeve from an old sweatshirt and buff it, as if I were sanding with it. They ussually turn out nicely. I like to finish with Dr. Kirks micro magic polish (I think that is waht it is called) and then Mylands high friction polish on top of that. They ussually shine like glass. I finish woods the same way, just have to sand the acrylic a bit more with the 400 grit to get out all those fine scratches.

 

[PlutoPens]

With acrylics I wet sand.

For wood, I've been experimenting with wet verse dry and haven't figured out entirely whats works best for me.

 

[steve worcester]

Primary reason to wet sand is to prevent "balling" where the material being sanded balls up and coats the sandpaper. Abranet is going to further help this, as it will allow the threads of abrasive not to get clogged and ginned up with the material.

This gets more important with higher grits as the material clogging will act like a lower grit and cause scratches the higher grits can't remove and causing you to step down in grits, almost starting over.

As far as going from 400 to polish, if you go higher, say 1000, you would have better results and spend less time polishing. The other devil in the details with the polishing is to go even higher, say 4000 grit with acrylics and then the polish isn't filling as big of fissures of scratches (or trying to remove as big of scratches, causing you to apply more pressure) and when it gets worn away from use, it will still look polished.

I also saw someone commenting that they go to 12000 (or some such) grit and then applied a decal (or CA finish). Film finishes (and decals) need a tooth in the material to stick. Like if you were applying lacquer to a 12000 grit finish, it doesn't soak in as much and can't give the foundation for the subsequent layers to adhere to and allow a long term quality finish.

 

[pendrijo]

Lots of debate on wet vs dry. Both have there pluses. I prefer wet Im more old skool though what I mosly like about wet is you don't breathe in all the dust. But in saying that if Im knocking back a car after it has been 2k primed I usually use 120 to 180 on a speedfile dry then prime again and then wet rub ready for the topcoat. The trend now in most shops is to dry rub its a lot quicker with a DA sander.