I need help with updating the crossover in my Polk model 10 speakers.

turkeyaddict

I'm new here, but work with wood - a lot.

Burnishing involves bending of wood fibers, whereas sanding or scraping are technically cutting/removing wood fibers.

You can sand some woods with 800 grit paper and still cut, whereas others you can burnish with that grit. It really depends on the wood species and its density, grain pattern (open or closed) and amount of natural resin in the wood.

Burnishing/polishing will bend the fibers and fill the pores, so you don't want to use a product that must penetrate - ie., don't stain a piece that's been polished. However, burnished pieces can still be finished with various sealing type finishes such as polyurethane, lacquer, etc. Most commercial furniture pieces that are sold 'natural color' and produced on a lathe are often lightly burnished before their final finish (usually an industrial lacquer or epoxy).

I don't know of any wood species you could burnish below 400 grit, and burnishing with 400 grit typically requires a solvent with a very dense wood (like ipe) being run at high speed on a lathe. Most people burnish/polish with bags or shavings...