Things to Consider When Installing Sealants in a Hot Environment

Modern sealants are equipped with unique material characteristics. They bond any surface to any other surface, deliver enviable elastomeric properties, and they can withstand any number of intrusive factors. That latter feature includes everything from acoustic attenuation to thermal resistivity. Reliable by design, we should note that the chemical stuff is still reactive to heat when first applied, so we need to assess thermal conditions before beginning installation.

Time Runs Faster

A hot environment causes chemical reactivity to accelerate. Due to this added energy, sealants cure faster, so there’s less time available when the product is first worked onto a surface. In dealing with this issue, technicians assess ambient temperature before applying the product. Additionally, the surface temperature in and around the join area must also be evaluated, as parts conductivity will also influence the cure time.

Expanding to Meet the Day

Summer installation practices are just that bit different from the winter months. The chemical compound naturally expands when the environment is hot, so account for this factor when applying the sealing layers. This is an environmental maxim that affects many industries. Electrical distribution grids, for example, hang cables loosely from their poles so that there’s plenty of room for the wiring to contract during colder months. In addition, wood and metal building materials expand at a different rate, which mandates a knowledge of heat-related installations during these peak seasonal periods.

Work Exotherm Aware

Similar to the above concern, this topic again concerns expansion and contraction, but the heat we’re debating is internalized. Periods of chemical reactivity can produce their own heat. The compounds mix and interact, become active when a curing agent is introduced, and bond energetically. This is a counter-intuitive effect, which means it must be accounted for during the installation phase in much the same manner as we addressed the external presence of heat. In short, the glutinous stuff will generate its own heat, resulting in a temporary expansion effect.

Bubbling and Blistering

Not all sealants are created equal. Closed cell types and open cell products cure differently. Substrates dry unevenly, exterior membranes harden irregularly, and bonding surfaces distribute thermal energy unevenly. Regardless of the cause, the result is an unsightly series of bubbles, blisters that may undermine the isolating properties of the product.

Once cured, a sealing compound is amazingly stable. It’s during the drying stage that problems can cause trouble. Heat is energy, after all, a thermal force that induces a change in reactive materials.