Cured TotalBoat varnish products, including TotalBoat Halcyon, TotalBoat Lust, and TotalBoat Gleam 2.0 spar varnish, can tolerate temperatures in the 130-150°F range, such as on a piece of varnished wood exposed to the sun on a hot summer day. This is the maximum service temperature range for TotalBoat varnishes. At temperatures higher than this, the heat causes the varnish to soften; the varnish can also delaminate due to the wood's natural expansion in higher temperatures.