Freezing

In detail

Freezing changes the mechanical properties of a deposit rather than its chemistry. Chewing gum, candle wax, tar, adhesive and modelling clay are all soft enough at room temperature to smear when pushed and to soak further into a fibre when warmed. Chilled hard, they become brittle and separate from the surface in pieces, which converts a spreading problem into a lifting one. That is the honest mechanism, and it is worth stating because the alternative approach is the one that feels intuitive: applying heat to melt a wax or gum makes it more mobile, drives it deeper into a pile or weave, and turns a defined lump into a diffuse greasy area. The carpet institute's four wax entries are notable for naming no heat method at all. Freezing's limits are equally worth stating. It works on deposits that are thermoplastic, so it does nothing for a stain that has dyed the fibre, and it usually leaves a residue that still needs a solvent afterwards. It is also a treatment that must not be applied to a material that becomes brittle itself — some plastics, some finishes and some adhesives crack rather than releasing.

What works

• Freezing is effective against Chewing gum Established practitioner practice

  Chilling makes the deposit brittle so it breaks off. Warming it does the opposite and spreads it.

Why

• Freezing is explained by Mechanical action and abrasion