What is Mountain Grout Accelerator, why is it necessary, and how it is best utilized?  Some in the industry call the Part B that comes along with single component resins “catalyst.”  At Green Mountain International, we call our Part B “Accelerator” to remove all doubts about its function. Mountain Grout Accelerator is a blend of catalysts in a compatible plasticizer.  It’s purpose is to speed up the reaction time of the polyurethane resin.  As installers increase the level of the Accelerator, the reactivity gets faster.  However, there is a point of diminishing returns.

Testing shows that the reactivity gets much faster when the Accelerator level is increased from 1.25 to 2.5 %.  However, increasing from 2.5 to 5 % gives only minimal decrease in reaction times.  We typically do not recommend using more than 5 % Accelerator in the majority of applications.

Following are a couple specific examples to further illustrate.  At 77 F, Mountain Grout Classic’s rise time is about 4 minutes with 1.25% Accelerator and about 1 minute and 5 seconds with the standard 2.5% (one pint) Accelerator.  Mountain Grout Ultra’s reaction time goes from about 7 minutes to 3 minutes to 2 minutes and 15 seconds when using 1.25%, 2.5% and 5% Accelerator respectively.

Not all jobs require the same amounts of Accelerator. Give a Mountain Grout Representative a call to discuss your specifics and find the best approach to your challenge.

It is important to note that if installers are using a UL Classified Mountain Grout Product (Flexible or HL-100) on a potable water job, one pint of Accelerator – no more, no less – is required.  Why?  Because that’s how UL tested it to make sure it is safe, so installers have to use the same ratios that were tested to ensure a safe result.