I wanted to thoroughly cleanse a chain before trying out the wax/teflon/moly combo that the Friction Facts guy used. In order to clean off the previous lube with all of its gunky debris suspended in it I put the chain into a little plastic bucket I got from the paint section of Home Depot, put the chain in, sloshed it around with some gasoline, etc.

The gas got all nasty black and whatnot, pulled the chain out, rinsed it in another small bucket with some denatured alcohol, let it dry, waxed it, etc.

On a wild hair I thought I'd put a magnet under the bucket to see if I could attract some steel wear particles and see how much there was. The magnet I used was a round rare earth magnet, the super strong kind.

Low and behold over the next little while almost all of the black cloudiness settled out, but it didn't just settle out, it actually gathered in a tight circle over that magnet. I picked it up and moved the magnet around under the bucket and the gunk would move around with it.

It appears to me that the microscopic steel wear particles from the chain got trapped in whatever other gunky debris there was, and caused the whole mess to be attracted to the magnet.

I've since been rinsing my chain in the gas again every week or two before rewaxing the chain, and every single time there's a layer of gunk stuck to the magnet. This evening I rinsed my chain, which hadn't been waxed in the last couple of weeks, and then suspended a rare earth magnet directly into the gas from a piece of wire and swirled it around the black cloudy gas, and when I pulled it out there was this ring of black gunk stuck all around the edge of it. Of course the gas doesn't go completely clear now that I'm rinsing off the waxy lube because of the moly content, which darkens it but isn't magnetic. It does clear up considerably, but the moly prevents it going completely clear now.

For some reason I found that fascinating. Has anyone noticed this before? I keep thinking there's got to be a way to make a little plastic container that would keep a bike chain separated from the magnet, but allow sloshing the gas (or whatever degreaser you use) to flow over the magnet and pull all the wear particles out so that when you pull the chain out it's not still got wear particles stuck to the surface. I may 3D print a little plastic insert that would hold the magnet down at the bottom of the bucket, then have a raised screen an inch or so from the bottom of the bucket that stops the chain from going all the way down into it.

I'll see if I can get some pics of this. It just blew me away that I got so damn much wear particles out of my chain when I first thoroughly cleaned it before the first waxing (I'd been using conventional oil lubes until then), and that I still get a considerable amount of this crap sticking to the magnet when I rewax the chain every couple of weeks. I also thought it was really interesting that the wear particles seem to carry most of the other gunk with them when sticking to the magnet. I put some of this gunk on my finger and let it dry (the gas dried really quickly) and it had a consistency sort of like a fine powder, not at all chunky or with noticeable particles, though I did see some noticeable metallic particles in the gunk when I looked at it under a 30x loupe.