Fenwick's HC-1 is a mostly biodegradable cleaner that uses the soap-and-abrasive principle rather than solvents. It’s mild on your hands and relatively mild on the environment but still does an excellent job at removing oil and grease.
The abrasive is tiny polyethylene beads (ie. plastic, so not readily degradable). It feels like gritty soap – or like carbon assembly compound, which also uses poly beads. In fact, with nothing here that would damage carbon ﬁbre, HC-1 would double up as an anti-slip paste for your composite seatpost. Why take two bottles into the workshop?
This article was originally published in Cycling Plus magazine.