There's a whole lot of information on tumbling and sanding media. I certainly won't go into it here, but there are some important basics. For example, there are two basic ways abrading media is offered:

• coated abrading media like sandpaper and polishing papers
• loose abrading media

The great thing about sandpaper is its versatility. It can be used manually, attached to sanders or cut up and used in rotary and vibrating tumblers. Other types of media are designed specifically for tumblers. These include ground corn cobs, crushed walnuts, ceramic and plastic media. Those are called tumbling media (surprise surprise). ;-)

Knowing what works best in any given situation isn't necessarily easy and it doesn't help when you're trying to identify what works with polymer clay because most suppliers won't have that experience or they pass on the wrong information. If you're trying something new, be prepared to run a test or two.

It is important to keep in mind is not all media will work well with polymer clay. Some media is too coarse or aggressive and will tear up a soft material like polymer clay. I found that with the finer loose media (like rottenstone and pumicestone), the particles tend to lodge themselves into the polymer clay surface. However, I have heard some use crafting sand with success.

With sandpapers , it's important to properly step through progressively finer media as you sand. That's why it is important to know the coarseness of the materials. Plus you need to know which standard the media is classified under. Here are a few used for sandpapers:

• CAMI (of ANSI)
• FEPA (P [coated])
• JIS
• Micron

Think of the standards like currency. When saying 100, it's important to know if you're talking dollars, yen, sterling pounds, euros. A 300 grit in FEPA is different than 300 in CAMI. It is very important to not mix standards unless you know that grit's equivalent in another standard. When it comes to sandpapers, until you're experience, use same brand for all your papers.

Here are a few excellent high level descriptions about sandpapers and other abrasive media:

• www.i-car.com
• www.onlineindustrialsupply.com FAQ
• www.sizes.com
• users.ameritech.net
• process-equipment.globalspec.com
• www.norton abrasives (a PDF file)
• kramer industries - tumbling media

Want some basic information about sanding, including sanding tools and the best way to hand sand? Click here.

If you are like me and have all kinds of sanding materials, it might help to know how they compare with each other, as far as how coarse they are.

I decided to revisit how to use my vibrating tumbler.

Summer 2007

OK. I know sandpaper sheets glued back to back and cut into tiny pieces works. But, hey, I'm lazy, so making those in various grits, gluing, cutting, etc. taxed my patience to no end.

I decided to explore, again, tumbling media - specifically which ceramic and/or plastic tumbling media will work in my vibrating tumbler when processing polymer clay pieces. Rio Grande was my source for this kind of media.

Apparently no one has done this with polymer clay, at least commercially, so I was on my own.

20 Aug 07

Using Rio Grande's Plastic Abrasive, Clean Cut Media: Fine Cut , 5/16"

• After vibrating for more than 12 hours, it kinda worked, in that the beads were not horribly gouged and the media did seem to sand the beads' surface to the approx equivalent to or a little less than 400 grit.

I did the following steps:

1. Put about 3 lbs of the media info the tumbler
2. add about 40-50 beads
3. turn on the vibe tumbler
4. very slowly pour in a small amount of water.
5. Check every hour or so, adding a little bit more water if the media looks dry.

It's important to pour the water in slowly because the tiniest amount of water drastically effects the vibrate tumbling motion. Too much water dampens the proper complex action.

Results? Not the most promising. I was concerned about the sharp edges of the pyramid shapes and I was right. While the surface of some beads seemed ok, quite a few were pitted. What I don't get is why some beads were pitted, but most were not.

Vibrating Tumbler Movie

1 Sep 07

Using Rio Grande's Ceramic Abrasive media, heavy cut , 5/32" cylinder

• At first, this version didn't seem to be significantly coarser when used in a vibrating tumbler. So I tried this media with beads in my Lortone rotary tumbler. It's way too rough.
• Retried in vibe tumbler again - 12 hours. Not good.

Rio Grande also sells porcelain beads, classified as being very fine, meant to polish metal, a adequate substitute for stainless steel tumbling shot.

According to Judy Summer, a Sandy Camp Retreat friend with 30 years of jewelry making experience, porcelain beads aren't quite as fine as Rio Grande pitches.

My hope is they could be the final sanding stage for tumbling polymer clay. However, those porcelain beads are quite pricey. So, that experiment is on hold for now.