Can you accelerate polyurethane sealant cure?
For Vulkem 116, Tremco names a catalyst. The data sheet doesn’t give a mixing rate or an accelerated cure time.
Yes, for Vulkem 116: Tremco says you can accelerate cure by adding Vulkem Catalyst 45/116. That permission applies to this sealant and named catalyst. The sheet doesn’t specify how much to add, how to mix it or how soon the joint can enter service. Get those instructions from Tremco before planning around a shorter cure.
Confirm the catalyst instructions before ordering
Got a fixed date for a concrete joint to be ready? Before you buy material, give Tremco the sealant name, joint width and depth, substrate, expected site conditions and your deadline. Ask for the accelerated-cure instructions for that job.
Don't guess the catalyst dose. Vulkem 116's sheet names the additive, but you'll need to ask how much catalyst to use and which packaging is compatible. Get the mixing procedure too, along with the working time after mixing and the wait before the intended exposure.
Six hours is skin time
The Vulkem 116 property table lists a typical skin time of 6 hours under ASTM C679. Separately, it lists a typical tack-free time of 30 hours at 23°C and 50% relative humidity. The sheet doesn’t attach those temperature and humidity conditions to the skin-time row.
Neither figure is labelled as full cure or as a result with catalyst added. Don’t use either one as the promised handover time for an accelerated joint.
The application limits still matter
Exterior use only. That's the approval for Vulkem 116, a single-component polyurethane sealant that cures with moisture. Tremco prohibits using it inside an occupied building, even if the occupants are away while you apply it.
Moisture-curing doesn’t mean you can apply it to a wet joint. The sheet says not to apply Vulkem 116 over damp, green or contaminated surfaces. It also prohibits use in chlorinated, potable, heavy or waste water.
The supplied sheet gives no heat, misting or other cure-acceleration procedure. Use the named catalyst route only with the manufacturer’s application instructions.
Take the deadline to the supplier
Review the [Vulkem 116 product details](/vulkem-116/), then send Cranco your joint dimensions, substrate, exposure and required completion time. Ask for the applicable Tremco catalyst instructions so you can settle the method and schedule before the crew starts.