New Rislone Liquid Copper Block Seal Intake and Radiator Stop Leak is the only one-step copper block seal on the market, according to the manufacturer. Simply pour it into the radiator, idle the engine for five minutes, cool, top off with coolant and go. Other products require a complete system flush, plus a number of additional steps, with an average six to 10 hour timeline for completion. Liquid Copper uses an advanced antifreeze-compatible sodium silicate liquid glass formula so no draining of the cooling system is required. It works with all types and brands of antifreeze.