TOUGH-SEAL™ 21 has a faster 10-20 minute working time and a Shore Hardness of 64A, which is similar to the hardness of a car tire. TOUGH-SEAL™ 21 reaches 94% of its full hardness after an overnight cure or with a heat cure of 1 hour at 80°C (176°F). TOUGH-SEAL™ does not exotherm or shrink during curing, therefore there is no embedment stress induced on the electronic components that could cause damage and failure of the PCB or electronic assemblies. Sensitive electronics can be potted safely with low embedment stress TOUGH-SEAL™.
With a high elongation of 225% when fully cured, TOUGH-SEAL™ 21 maintains exceptional flexibility and thermal cycling stability from –40°C to 150°C (-40°F to 302°F) without pulling back, wilting, or cracking. This ensures a tough seal that will stop moisture or other contaminants from damaging sensitive PCB’s and electronics.
TOUGH-SEAL™ has very aggressive adhesion to aluminum, making it a perfect choice for potting aluminum housings in LED lighting applications. TOUGH-SEAL™ bonds extremely well with most polymers. For housing and wire insulation materials that are exceptionally difficult to bond to, we offer our KEY PR1200 PRIMER, an aggressive adhesive promoter that is simple to use.