Originally posted by Mr. Ron:
I carry a small roll of 1" emory cloth on my kit for this exact purpose, cleaning surfaces for bonding and cleaning sparkplugs. I've also used it for removing glazing from my brake hub. I prefer the cloth because of its durability and packability, and you can use it wet with oil or mineral spirits as a lubricant. It also fits perfectly into a film container, and works best for prepping tires for patches.
NOT a good idea to use sandpaper of any kind for brake shows - if you leave behind just a very few granules of abrasive, think what it can do to your brake hub. I use a coarse file for the job. Otherwise, agreed!
For a cylinder I'd use a larger piece of wet/dry paper to finish, and emery cloth to clean up nasty marks and aluminum transfer. Or better muriatic acid (HCL, or hydrochloric acid - and if memory serves, you can make HCL with salt and sulphuric acid - or battery acid
but the proportions escape me - it's out there somewhere) works wonders on aluminum left on iron cylinders, much better than sandpaper of any type. Gets it back to almost new, with small touch-up sanding to finish it off.
Cleaning a cylinder after hand honing - LOTS of gasoline/petrol and white paper towels to make sure it's REALLY clean - much the same as for brake shoes. Also recommended is to wash it in lots of hot soapy water, then IMMEDIATELY dry thoroughly, and oil the cylinder so it won't rust.
Seek, and ye shall find.
Inspiring, Informing and Connecting travellers since 1997!