Compounds with a wide liquid range could also protect steel against corrosion, especially in mechanical workshops. Many steel tools can't accept a paint or protective layer, which would be inaccurate or too soft, so their functional surfaces remain blank and get covered with oil. Though, these petrol cuts evaporate within weeks or are unpleasantly viscous to the fingers. Compounds with a lower melting point shall remain mobile but not evaporate.
Candidates must be non-toxic, water repellant, excellent at wetting steel, with low odour, preferably good lubricants at low speed and high pressure, and non-flammable. 500g might retail at 10€, so production should cost under 2€/kg.
Wind music instruments need lubricants too, which are already special productions. Slide trombones, rotary and slide valves need very pure mobile lubricants that don't evaporate, while sealant corks need half-thick greases.
These must be totally innocuous, absolutely water-repellant, benign to wood and varnishes and Cu-Ni-Zn-Ag alloys over decades, resist carbonic and some hydrochloric acid, with low pleasant odour or rather none, good lubricants at low speed and low pressure, excellent at wetting metals. 50g can retail for 20€, so production should cost under 20€/kg.
Marc Schaefer, aka Enthalpy