DOWSIL™ 844 RTV Adhesive Sealant

Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features

One-part moisture cure
Fast processing
Broad adhesion

Product Description

DOWSIL™ 844 RTV Adhesive Sealant is a one-part, non-flowing moisture cure adhesive featuring a neutral alkoxy cure system. Designed for faster in-line processing, it offers a fast room temperature cure and high green strength. Its non-flowing nature and durable adhesion to a wide range of substrates make it ideal for various industrial bonding and sealing applications.

Product Key Features

One-Part Moisture Cure - cures at room temperature in an environment of 30 to 80 percent relative humidity, eliminating the need for curing ovens.
Fast Processing & Green Strength - provides high green strength and a quick tack-free time of 25 minutes (at 25°C/40% RH) for faster manufacturing throughput.
Non-Flowing Rheology - maintains its position upon dispensing, supporting both automated and manual dispensing systems.
Robust Mechanical Profile - cures to deliver a Shore A hardness of 37, a tensile strength of 2.2 MPa (320 psi), and a high elongation of 400% for added stress relief.
Broad Adhesion - delivers durable, unprimed adhesion to many reactive metals, ceramics, glass, and selected laminates, resins, and plastics.

Applications

This adhesive fits applications requiring fast room temperature curing, high elongation to relieve stress, and reliable adhesion across diverse substrates.

Module Assembly: Ideal for the bonding and sealing of modules and multi-component assemblies.
Gasketing: Highly effective as a formed-in-place gasketing material].
Automated Production: Suitable for automated or manual dispensing systems where faster in-line processing is required.

Product Family
DS-844

1. Select Package Type

310Ml Cartridge

Catalog Product

Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.

Shortest leadtime

Shipping in 5 weeks

Contact for Pricing

Packaging

TDS, SDS & Technical documents

Specifications
Additional Information

Technical Specifications

General Properties

Specific Gravity

Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.

For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.

1.35

Physical Properties

Viscosity

Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application

paste mPa.s

Mechanical Properties

Hardness
Durometer (Shore A)	37

Tensile Strength
Tensile Strength Tensile Strength Tensile strength determines the resistance of a material to break under tension and it measures how much elongating load (or tensile stress) it can handle before fracture. To make it simple, it measures how much force we have to apply when pulling apart a material before it breaks.	2.2 MPa

Elongation

Elongation
Elongation is the process of lengthening something.

It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.

It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.

400 %

Tensile Modulus
Tensile Modulus @ 21°C	0.69 N/mm2

Additional Information

One-Part High Green Strength Silicone Adhesive

DOWSIL™ 844 RTV Adhesive Sealant

DOWSIL™ 844 RTV Adhesive Sealant is a premium, one-part, non-flowing moisture-cure silicone adhesive engineered for high-performance industrial sealing and structural assembly. This room-temperature vulcanizing (RTV) system requires no pre-mixing or specialized heat ovens, utilizing atmospheric moisture to develop high early green strength. Formulated to provide exceptional elongation for added stress relief, it delivers durable primerless adhesion across a broad variety of substrates, optimizing cycle times for rapid in-line production processes.

One-part moisture cure 25 min tack-free time Neutral alkoxy cure system High early green strength

Technical Data Sheet Safety Data Sheet (SDS)

Typical values only. Performance parameters are measured at standard ambient room temperature conditions.

DOWSIL™ 844 RTV Adhesive Sealant

Key Features

One-part RTV chemistry eliminates multi-component volumetric mixing machinery and capital costs.
High green strength construction allows immediate part handling and faster in-line processing.
Thixotropic non-flowing paste profile resists running or slumping on vertical or overhead component seams.
Neutral alkoxy moisture-cure formulation cross-links cleanly without generating corrosive by-products.
High elongation value (400%) provides optimal stress relief across varying joint assemblies.
Stable chemistry maintains original mechanics over an extensive operational footprint from -45°C to 200°C.

Processing Summary

Ease of Dispensing: Supplied as a ready-to-use structural compound suitable for automated or manual needle dispensing, yielding a steady 120 g/min extrusion rate.

Working & Tack-Free Windows: Working life spans from a few minutes up to a half hour until a surface skin initializes. Achieves a complete tack-free surface in 25 minutes at 25°C and 40% RH.

Inward Cure Progress: Solidifies from the exposed surface inward at an approximate depth tracking rate of 0.25 inches (6.35 mm) per seven days, driven by relative moisture in the air.

Cure Optimization: Attains over 90% of full engineering mechanics within 24 to 72 hours. Processing throughput may be further quickened via mild heat below 60°C (140°F).

Handling and Application Guidance

Process Notes

Storage and Shelf Life

Maintains a stable 12-month usable shelf life from the date of production.
Store material at or below 25°C (77°F) inside original unopened container lines.
Take special precautions to minimize head air space and isolate material from atmospheric moisture contact.
Purge partially depleted bulk containers with an inert gas cover such as dry nitrogen.

Surface Preparation

Joint surfaces must be thoroughly clean, dry, and cleared of manufacturing fluids, greases, or dirt.
Degrease using DOWSIL™ OS Fluids, naphtha, mineral spirits, or methyl ethyl ketone (MEK).
Avoid pure acetone or isopropyl alcohol (IPA) alone, as they do not remove heavy oils effectively.
Apply fine mechanical surface abrasion whenever possible to expand active bonding area.

Material Optimization & Handling

Execute tooling actions and part mating swiftly before the surface layer skin initializes.
Do not apply in highly confined manufacturing spaces completely restricted from atmospheric moisture.
Run lab-scale lap shear evaluations to establish minimum line cure tracking prior to full production.
Clean up any uncured paste overspray or line squeeze-out using standard ketone-type solvent systems.

Typical Properties

Engineering Data for DOWSIL™ 844

Physical & Mechanical Performance Properties

Mechanical Property	Typical Engineering Value	Condition / Standard
Appearance	Non-slump, non-flowing paste	-
Extrusion Rate	120 g/minute	-
Flow - Slump	≤ 0.2 inches (0.6 cm)	-
Specific Gravity	1.35	-
Durometer Hardness	37 Shore A	-
Tensile Strength	320 psi (2.2 MPa)	-
Elongation at Break	400 %	-
Tensile Modulus	100 psi (0.69 MPa)	-
Tear Strength	35 ppi	Die B tear resistance
Unprimed Adhesion (Lap Shear)	180 psi min (1.25 MPa)	Aluminum

Adhesion Fail Mode Engineering Target: To achieve optimal, long-term bond integrity across selected structural sub-assemblies, a target of 100% cohesive failure of the silicone rubber in lap shear testing is desired.

Cure Schedule

Green Strength Development

Applications

Where DOWSIL™ 844 Fits

Module Assembly

Perfectly configured across demanding industrial sub-assemblies where rapid part handling and robust unprimed structural bonding are essential.

Structural bonding and sealing of modules.
Attachment of multi-component industrial assemblies.
High elongation provides stress relief under vibration.

Formed-in-Place Gasketing (FIPG)

Acts as a durable, fluid-tight non-slumping liquid gasket alternative to traditional pre-molded rubber profiles for component enclosures.

Conforms cleanly to complex or irregular mating surfaces.
Thixotropic slump limits stay within ≤0.2 inches.
Eliminate traditional pre-molded gasket tooling steps.

High-Speed In-line Processing

Formulated for automated fluid dispense loops requiring instant part movement and fast room-temperature tack windows.

Enables faster manufacturing throughput rates.
Reduces handling wait windows down to 10–90 minutes.
Eliminates continuous high-energy oven bake operations.

Product Demo

See One-Part Moisture-Curing RTV Silicone Dispensing Methods

Observe the high-precision processing of one-part non-flowing industrial RTV silicone adhesive sealants via automated needle dispensing setups. This practical reference highlights best practices for balancing track extrusion parameters, checking non-slump bead profiles, and verifying surface handling stability before complete room temperature cross-linking completes.

Package & Support

Standard Packaging & Technical Help

Standard Packaging

Typically packaged in convenient 330 ml cartridges for manual application guns.
Bulk delivery configurations are available in heavy-duty pails ranging from 18 to 25 kg.
Supplied in nominal 3.6-kg, 18-kg, and 200-kg container net weights depending on product choice.
Special bladder pack or tube sizes can be evaluated for distinct project needs.

Technical Help Capabilities

Assisting assembly lines with process tuning to eliminate curing ovens and associated energy costs.
Evaluating substrate profiles to check unprimed cohesion limits over metals and engineering plastics.
Configuring needle automated fluid tracks to maximize specified 120 g/min extrusion rates.
Advising on texturing or secondary primer options when joining low surface energy matrices.

Technical Guidance

Tips and Troubleshooting

Issue	Recommended Action
Premature layer skinning or surface tearing during finishing tooling steps	Surface skin over progresses fast, typically commencing within a few minutes up to a half hour. Ensure any smoothing adjustments or spatula profiling operations are completed before the surface skin initializes. Perform assembly line joins immediately after application to guarantee complete adhesive transfer across boundaries.
Incomplete structural cross-linking down through joint core zones	One-part RTV chemical cross-linking relies strictly on atmospheric moisture and progresses inward from the exterior skin. Do not utilize this moisture-cure product in highly confined or enclosed pockets lacking proper air access. Be aware that deep-section cure dimensions advance at a slower standard parameter rate of 0.25 inches per seven days. Expect extended cure tracking behaviors if the plant floor surrounding relative humidity indices fall low.
Adhesion tracking breakdown or low lap shear force values over difficult substrates	Unprimed structural bonds will not stick successfully onto non-reactive substrates like Teflon, polyethylene, or polypropylene. Highly plasticized plastics or rubbers can leach mobile plasticizers over time, which act as unwanted bond release agents. Verify all targets are cleanly washed of mill fluids or grease using DOWSIL™ OS Fluids, naphtha, mineral spirits, or MEK. Apply specialized surface configurations such as chemical etching, inline plasma treatment, or compatible DOWSIL™ Primers.

Next Steps

Ready to Qualify DOWSIL™ 844 RTV?

Tell us about your performance, design, and manufacturing challenges. Share your specific substrate pairings, joint geometry designs, takt time constraints, and environment parameters. Our global technical support team is prepared to put our silicon-based material expertise and process knowledge to work for your production floor.