Dow Corning Products Silicone Sealants
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Regardless of how harsh the environment or how extreme the temperatures, we are sure to have a Dow Corning® sealant to meet your needs.

This guide will assist you in selecting the best sealant for your specific application needs.  A technical data sheet is available for all products.

Acetoxy

Dow Corning® 730 Solvent Resistant Sealant

  • Primary Use – Bonding, sealing and caulking where resistance to fuels, oils and solvents is required.
  • Applications – Assembling and repairing fuel lines and tanks; bonding components exposed to fuels, oils, solvents; making formed-in-place gaskets for chemical compressors, fluid-filled distributors and transformers; repairing rubber linings exposed to corrosive conditions; sealing pipe joints on lines carrying corrosive chemicals.

Dow Corning® 732 Multi-Purpose Sealant
Primary Use – General purpose bonding and sealing; making formed-in-place gaskets.
Applications – Sealing flashing, vents, flues, gutters, marine cabins and windows, electrical boxes; caulking joints in sheet metal stacks, ductwork; bonding appliance parts, signs and sign letters; Adhering auto trim, appliance trim, name plates; making formed-in-place gaskets for compressors, gearboxes, pumps.

Dow Corning 733 Glass & Metal Sealant
Primary Use – Bonding and Sealing
Applications – Bonding and sealing appliances, heavy equipment, marine equipment, recreational vehicles.

Dow Corning 734 Flowable Sealant
Primary Use – To fill voids, cracks, crevices; conformal coating for connections and battery terminals.
Applications - Coating mechanical devices; making formed-in-place gaskets for compressors, gearboxes, pumps; potting electrical terminals; sealing ammunition fuses, trailers, truck cabs.

Dow Corning 736 Heat Resistant Sealant
Primary Use – Sealing and bonding applications exposed to temperatures as high as 600°F (315°C).
Applications – Sealing fired heaters, flanged pipe joints, access doors, moving oven belts, industrial ovens and boilers, plywood drying ovens, bag filters on smoke stacks, flues on gas appliances; bonding appliance parts, electrical and electronic equipment; caulking joints in sheet metal stacks, ductwork.
Dow Corning 786 Mildew Resistant Sealant
Primary Use – General purpose coating for protecting motors and electrical equipment; maintenance coating.
Special Characteristics – Excellent moisture protection and resistance to sand, dust, dirt particles; easy to apply, thing coatings will not run or drip when applied to vertical or overhead surfaces.
Applications – Coating motor windings, bus bars, splines, connectors, transformers, insulators, trailers, truck cabs, wooden pole tops.

Oxime

Dow Corning® 236 Dispersion Coating

  • Primary Use – Release coating for protective surfaces from weathering, corrosion and dirt.
  • Special Characteristics – Excellent release; weather resistance; excellent electrical insulator
  • Applications – Easing clean-up of latex manufacturing equipment and paint-spraying operations and removal of flash in urethane and polyester molding; preventing adhesion and build-up on conveyor belts, paper and fabric rolls; reducing build-up on waste-handling equipment.

Dow Corning® 735 Oil Resistant Sealant

  • Primary Use – Sealing and adhering general industrial equipment, vehicles and other applications where resistance to oil, coolants and lubricants is required.
  • Applications – Sealing oil circulation systems, machine housings, conveyors, piping, oil containment troughs, dikes and barriers; making formed-in-place gaskets for gearboxes, engines and pumps.

Dow Corning® 737 Neutral Cure Sealant

  • Primary Use – General manufacturing assembly operations where quick cure and good adhesion are important.
  • Applications – OEM and assembly applications; substitute for mechanical fasteners on appliances; adhering plastic moldings to plastic substrates; waterproofing components, sealing coaxial connectors, protecting instrumentation; may be used on concrete and masonry.

Alkoxy

Dow Corning® 738 Electrical Sealant

  • Primary Use – Bonding and sealing
  • Applications – Bonding and sealing corrosion-sensitive electrical and electronic equipment

Dow Corning® 739 Plastic Adhesive

  • Primary Use – Adhering, bonding and sealing plastic and metal; making formed-in-place gaskets
  • Applications – Adhering auto trim, appliance trim and parts; assembling plastic toys; bonding gaskets in refrigeration units, signs and sign letters; caulking cement and masonry; making formed-in-place gaskets for compressors, gearboxes, pumps; sealing flashing, vents, gutters, marine cabins and windows; waterproofing leak proof tractor cabs.

Dow Corning® 748 Non-corrosive Sealant

  • Primary Use – Electrical sealing applications; food processing and transportation applications
  • Applications – Bonding and sealing electrical equipment, power and control connections, motors, cover plates, instrument lenses, regulators, junction boxes, control panels; sealing refrigerator and freezer liners.

Dow Corning® 832 Multi-Surface Adhesive/Sealant

  • Primary Use – Bonding, sealing and assembly where a non-corrosive sealant is required.
  • Applications – Sealing and repairing roof penetrations, gutters, concrete floor seams, marine equipment and windows, pipes, threaded connections; assembling original equipment components.

Dow Corning® – HM-2500 Assembly Sealant

  • Primary Use – Assembly, bonding, sealing, gasket and other applications that require instant adhesion and high green strength
  • Special Characteristics – 100% silicone, instant adhesion, ultra clear and cures to long lasting silicone sealant.
  • Applications – Hot melt reactive sealant that works well in OEM and assembly applications, very good adhesion, to most substrates without the need of a primer.  With its instant adhesion, parts can be shipped out quickly yet has a long open time, long pot life and low VOC.

Primers and Cleaners

Dow Corning® 1200 RTV Prim Coat

  • Primary Use – Significantly improves the adhesion of silicone sealants, to a wide variety of challenging substrates.
  • Applications – Improves the adhesion of silicone sealants, coatings and rubber to masonry, wood, granite, metals, glass, ceramics, plastics, rubbers and coatings.
  • Container Sizes – Can, pail and drum
  • Color – Clear, Red

Dow Corning® P5200 Adhesion Promoter

  • Primary Use – Significantly improves the adhesion of silicone sealants, with low VOC to a wide variety of challenging substrates.
  • Applications – Improves the adhesion of silicone sealants, coatings and rubber to masonry, wood, granite, plastics, rubbers and coatings.
  • Container Sizes – Can
  • Colors – Clear, Red

Dow Corning® OS-2 Silicone Cleaner and Surface Prep Solvent

  • Primary Use – Removing oils, greases, waxes and sealant residue – especially silicone; cleaning surfaces to be painted, bonded or sealed; replacing VOC solvents
  • Special Characteristics – VOC exempt (VOC = 0 g/L).  Certified as a Clean Air Solvent by the California South Coast Air Quality Management District.  Easy to use, low in toxicity, essentially odorless. Safe on plastics and non-corrosive to metals.  Ideal for diluting and tailoring the viscosity of silicones.
  • Applications – Cleaning plastics, metals, other surfaces, or preparing these surfaces for painting, bonding or sealing.
  • Limitations – This product may not remove highly polar contaminants.
  • Container Sizes – Can, pail and drum

 

Designed for Industrial Assembly and Maintenance

Silicon-based Dow Corning Sealants last longer and are more versatile than most organic polymer sealants.  They are durable, one part RTV sealant, cure at room temperature to a tough, rubbery solid with exceptional performance characteristics, and meet a wide variety of your industrial bonding and sealing needs.

Features of Dow Corning silicone sealants include:

  • Stability over a wide temperature range – When fully cured, our products can be used at temperatures ranging from -85° to 599° F (-65° to 315° C)
  • Weather resistance – High resistance to UV rays, radiation and weather prevents our products from hardening, cracking, crumbling, drying and becoming brittle.
  • Chemical stability – Our sealants do not readily degrade even under long-term exposure to many chemicals and atmospheric pollutants.
  • Good bond strength – Our products provide good adhesion to a wide variety of industrial materials, including glass, ceramics, and wood masonry, painted surfaces, and many metals and plastics
  • Electrical properties – Designed for a variety of applications, our products can be used in various electrical and electronic applications, including devices that are thermally cycled over a wide temperature range.
  • Low Flammability – IN fire conditions, silicone adhesives/sealants are reluctant to burn.  Many products comply with UL flammability standards.

When you specify an assembly and maintenance product from Dow Corning, you receive a solution backed by the world leader in silicone technology with more than 60 years of expertise and innovations.

Innovative Technology

Reactive hot-melt silicone technology provides instant green strength which can increase productivity, improve quality and reduce costs in industrial assembly applications.

Dow Corning® HM-2500 Assembly Sealant is a patented, neutral-cure reactive hot-melt silicone that is ideal for automated applications in the manufacturing of various components. When used with standard hot-melt dispensing equipment and an automated robot, HM-2500 becomes part of the productivity solution that enables parts to be produced faster, better, and more economically.

  • Immediate green strength – parts move efficiently from one step to the next
  • No “hold time” required – ship parts as fast as you make them
  • Long Pot Life and Long Open Time – material stability, is not heat cured, does not cure in line
  • Aggressive Adhesion – excellent primerless adhesion to metals, plastics, wood, and paints
  • Crystal Clear – ultra clear or select colors
  • Worker Friendly – non-hazardous formulation, very low odor, very low VOC
  • Neutral-Cure 100% Silicone Chemistry – cures to flexible, weather-resistant, silicone elastomer with outstanding durability and UV resistance.

 

Substrate Preparation
Although Dow Corning silicone sealants possess excellent bond strength, maximum adhesion is only attained on surfaces which are clean and dry.  Contaminants, such as dirt, grease, water, tar or rust act as release agents and prevent the formation of durable bonds

It is strongly recommended, therefore, that wet or unclean surfaces be properly prepared before sealants are applied.

  • Wipe contaminated surface with a clean, oil-free cloth.
  • Re-wipe surface with suitable cleaner or industrial solvent, such as IPA, mineral spirits, naphtha or ketones. Note: do not clean surface with detergent or soap. (Soap residue may act as a release agent.)
  • Rough rubber surfaces with sandpaper.  Make a spot check to determine the adhesion of the sealants for each application.  Bond strength will increase as the sealant cures.

How to Apply
Apply Dow Corning adhesives/sealants to on of the prepared surfaces, and then quickly cover with the other substrate to be bonded.  On exposure to moisture, the freshly applied material will “skin over” in about 5-10 minutes (depending on the product) at room temperature and 50% relative humidity.  Any tooling should be completed before this skin forms.  The surface is easily tooled with a spatula.

Use of a Primer
For maximum adhesion, the use of Dow Corning primer is recommended.  After solvent cleaning, a thing coat of Dow Corning primer is applied by wiping, brushing or spraying.  At normal room temperatures and humidity conditions (room temperature, 50% relative humidity), the primer should be allowed to air dry from 5 to 30 minutes.  The primer cures in contact with air moisture, low humidity will necessitate longer drying time.
The required drying time for a specific area should be determined prior to use.  Primer which was allowed to cure extensively will not promote adhesion anymore.  As a general rule, drying time of more than 6 hours at normal temperatures and humidity should be avoided.

Cure Time
After skin formation, cure continues inward from the surface.  In 24 hours (at room temperature and 50% relative humidity) Dow Corning adhesive/sealant will cure to a depth of about 1/8”.  Very deep sections, especially when access to atmospheric moisture is restricted, will take longer to cure completely.  Cure time is extended at lower humidity levels. 
As the sealants cure by reaction with moisture in the air, keep the container tightly sealed when not in use.  A plug of used material may form in the tip of a tube or cartridge during storage.  This is easily removed and does not affect the remaining contents.

Compatibility
Some Dow Corning adhesives/sealants release a small amount of acetic acid during cure.  This may cause corrosion on some metallic parts or substrates, especially in direct contact or when the cure is carried out in totally enclosed environment which would not allow cure by-products to escape.

Health and Environmental Information

To support Customers in their product safety needs, Dow Corning has an extensive Product Stewardship organization and a team of Product Safety and Regulatory Compliance (PS&RC) specialists available in each area.