Heat from Kinetic (or dynamic) Friction Kinetic (or dynamic)friction induced heat is an often misunderstood concept of polishing / compounding; abrasives require friction to breakdown, not heat; heat is just a resultant of friction between two surfaces. Kinetic friction is required to ‘level’ paint, which is simply the removal of paint to the lowest point of the paint defect. A finishing pad will not provide as much friction as a cutting foam pad, although they will both produce friction induced heat, whereas a wool pad, due to their composition, creates less friction induced heat but more kinetic friction than most foam pads. Polishing a paint surfaces transfer’s kinetic friction induced heat to the paint surface, thermoplastic polymers have both tensile strength and elongation (elasticity) which allow the surface to flex, expand and contract in accordance to surrounding temperatures, solvents, resins and other ingredients in polishes will expand causing the paint film surface to expand. As the metal substrate expands the paint moves with it, due to its elasticity, thereby becoming elongated (thinner) this is part of the cause of friction induced ‘burn’, you’re applying pressure and an abrasive to a less dense (‘thinner’) paint surface. Plastic has a much lower rate of thermal conductivity than metal, so it absorbs heats at a far greater rate. Kinetic Friction induced heat can cause a rapid temperature rise; (i.e. initial surface temp 80.oF, friction heat attained with a stationary cutting foam pad at 1,100 RPM for approx. ten seconds would be approx. 104.oF) the paint temperature can be checked by utilizing an instant read-out infra-red ‘gun type’ digital thermometer, paint surface ‘spot’ temperature should be limited to 110.oF < In accordance with the Society of Automotive Engineers (SAE) a localized (spot) temperature of 115.oF will cause the urethane clear coat to soften and the foam pad will cause scratching that is forced deep into the clear coat. An extract from one of a series of in-depth, unbiased detailing articles © TOGWT ™ Ltd Copyright 2002-2008, all rights reserved.
[Heat is your enemy...] Kinetic Friction induced heat can cause a rapid temperature rise (i.e. initial surface temp 80.oF, heat attained with a cutting foam pad at 1,100 RPM for approx. ten seconds is approx. 104.oF) the paint temperature can be checked by utilizing an instant read-out infra-red ‘gun’ thermometer, paint surface ‘spot’ temperature should be limited to 110.oF In accordance with the Society of Automotive Engineers (SAE) a spot temperature of 115.oF will cause the urethane clear coat to soften and the foam pad will cause scratching that is forced deep into the clear coat.
heat is actually good for paint to a degree, I find that buffing at 1600 to 1900 rpm with prima swirl actually gets the paint back to it's fresh off the gun result. though it does create some heat and requires slow and long jewelling down to finish down marring free
