May 05, 2022

Equipment, Application Guidelines, Cleaning, and Shelf Life and Storage of Pecora 985

For this week’s blog post, we dive into a comprehensive look at equipment, application guidelines, cleaning, and shelf life and storage of Pecora 985. Pecora 985 is a fast curing two-part, high modulus, neutral cure silicone sealant with a 480 mL dual component cartridge. This product was specifically formulated and compounded for use in shop fabrication and field installation or repair of structurally glazed systems. The basic uses of the 985 include: field applied structural glazing of glass and other substrates, in-shop structural glazing where a two-part sealant pump is not available, as a fast-curing adhesive for applications such as panel stiffeners, and field repairs of structurally glazed glass units.


  • Dispensing Equipment
    • Battery Operated: Meritool PowerPush 7000 Series Cordless Two Component Cartridge Dispenser, 20V 10:1 Mixpac 400 Type

  • Packaging
    • 490 mL 10:1 dual cartridge field kit
    • 12 cartridges per case (includes 12 static mixing tips, 3 threaded collars and 3 adapters)
  • Color
    • Base – White
    • Curing Agent – Black
    • Mixed – Dark Grey (color code 970)


Application Guidelines

  • Surface Preparation
    • Thoroughly clean joint surfaces and glazing areas with solvent to remove all foreign material and contaminants such as oil, dust, grease, frost, water, old sealants or glazing compounds and any protective coatings. Cleaning of surfaces should be done just prior to the sealant’s application. Avoid using soap, detergent, or water solutions as a cleaning agent. These products are likely to leave behind a form release film on the surface. Structural glazing requires even greater attention to surface cleaning. Technical Bulletin #56 addresses the proper procedures in greater detail.
  • Priming
    • The application of sealant primer may be required and should be determined via laboratory adhesion testing. Pecora requires that laboratory adhesion/compatibility testing on representative substrates and a glazing review be conducted for all structural glazing projects. Refer to the requirements published in Technical Bulletin #56. For most recent updates, please visit
  • Sealant Preparation
    • Install backup fillers, setting blocks, spacer shims and tapes as specified. Apply any required sealant primers. Prepare cartridges and apply sealant per the instructions under “Assembly and Application.”
  • Assembly and Application
    • Remove the collar and plug from the nozzle end of the dual cartridge (see figure 1.0). Dispose of plug and collar as these components are for packaging purposes only and will not be reused.


    • Preassemble the supplied adapter, static mixing nozzle, and threaded collar prior to attaching to cartridge (see figure 2.0). Begin by placing the static mixing nozzle over the male end of the adapter then slide the threaded collar over the nozzle and thread onto adapter to secure in place (assembled in top portion of figure 3.0).

    • Attach nozzle assembly to cartridge by aligning small and large orifices then “click” into place (see figure 3.0). The supplied adapter and threaded collar can be reused. Do not discard unless damaged.
    • Retract plunger rod and slide cartridge into cradle of dispenser taking care to align slotted area of cartridge within slots of cradle. Cartridge should be secure within cradle with nominal “play.”
    • Dispense approximately 50 mL of sealant then test uniformity via the “Butterfly Test” as described in Pecora Technical Bulletin #164. If necessary, repeat the purging process and Butterfly Test until the material is homogeneous.
    • Apply sealant. A new static mixing nozzle is required for each cartridge. Do not reuse the static mixing nozzles.


Excess sealant should be removed from all surfaces while still uncured using solvents such as Isopropyl Alcohol. Cured sealant is very difficult or impossible to remove completely without altering or damaging the surfaces to which the sealant has been misapplied.

CAUTION: Solvents used in cleaning may be toxic and/ or flammable. Refer to solvent manufacturer’s instructions and Material Safety Data Sheet. Precautions: Use with adequate ventilation or wear an appropriate NIOSH-approved respirator. Contact with uncured sealant or with vapors generated during curing may cause respiratory tract irritation. Contact with skin or eyes may cause irritation or allergic reaction. Avoid contact and wash thoroughly after handling. May be harmful if swallowed. Refer to Safety Data Sheet (SDS) for more information.

Shelf Life and Storage

Twelve (12) months when stored in unopened cartridges at temperatures between 50°F and 80°F. 

For more information about our glass and glazing sealants, please visit our website at Pecora representatives are available to assist you in selecting an appropriate product and to provide on-site application instructions. For further information and assistance, please call our Technical Service department at 215-723-6051 or 800-523-6688.


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