Can't say for sure.... I have never used a butyl sealant but have used butyl tape. We always used bed and glaze around the pitch weld and gasket ....and urethane between the glass and gasket.
The Dekaseal comes out of the cartridge like regular chalk/urethane but stays rubbery. I can place my finger onto it and it will not stick. It flashes off a tad and thens gets somewhat "harder" but it stays rubbery. When I talked to my ex boss at the auto glass place he had a wad of it sitting on the counter. It is formable and doesn't stick in a messy type fashion.
I unlocked the self locking gasket, applied the Dekaseal underneath, locked the gasket, then applied some in the pitch weld area under the stainless trim. Before I installed the stainless trim I ran a water hose all over the backglass and the leak was gone. No need to wait for the stuff to dry or anything. It is amazing type stuff... lol
