Technical Data Sheet

DOWSIL™ 993 Structural Glazing Sealant

FEATURES & BENEFITS Two-part silicone rubber

• Meets European standard for
structural glazing as developed by APPLICATIONS
EOTA working groups • Two-part silicone sealant for structural glazing (SG)
• Excellent adhesion to a wide range
of substrates including coated, TYPICAL PROPERTIES
enamelled and reflective glasses, Specification Writers: These values are not intended for use in preparing
anodised and polyester paint specifications.
coated aluminium and stainless
steel
Test* Property Unit Result
• High level of mechanical Base: as supplied
properties Color and consistency Viscous white paste
• Odorless and non-corrosive cure Specific gravity 1.32
• Excellent stability through wide Viscosity (100s-1) mPa.s 150,000
temperature range: -50°C to 150°C Curing agent: as supplied
• Resistant to ozone Consistency Viscous paste
Specific Gravity
• Stable viscosity for A & B - Catalyst black 1.05
components, no heating required - HV/GER black 1.06
• Suitable for use in impact-resistant - Clear & gray catalyst 1.01
window systems in new Viscosity (20s-1)
construction and retrofit in existing - Catalyst black mPa.s 25000
buildings - HV/GER black mPa.s 100000
• Structural capability - Clear & gray catalyst mPa.s 25000
ASTM D93 Flash point - closed cup °C 28
• The cured product exhibits
As mixed
excellent weathering Color and consistency White/black/gray**
characteristics, and a high non-slump paste
resistance to ultra-violet radiation, Specific gravity 1.30
heat and humidity Viscosity (100s-1) mPa.s 40,000
• Lot matching of base and curing Working time (25°C, 50% R.H.) minutes 10 to 30
agent not necessary Tack-free time (25°C, 50% R.H.) minutes 80 to 100
Corrosiveness Non-corrosive
• Different gray shades available
As cured - after 7 days at 25°C and 50% RH
(please refer to our color card) ISO 8339 Tensile strength MPa 0.95
ASTM D624 Tear strength kN/m 6.0
ISO 8339 Elongation at break % 130
ASTM D2240 Durometer hardness, shore A 40
Sealant dynamic design load Pa 140,000
Sealant static design load Pa 11000
Service temperature range °C -50 to +150
*
ASTM: American Society for Testing and Materials.
ISO: International Standardisation Organisation.
**
Please refer to our color card.

DESCRIPTION structural bonding of glass, metal and

DOWSIL™ 993 Structural Glazing other building components. Neutral
Sealant is a two-component, neutral alkoxy; cures at room temperature
curing silicone formulation giving off a small amount of alcohol.
specifically developed for the
TECHNICAL Mixing and dispensing Preparatory work
SPECIFICATIONS AND To obtain the ultimate physical Clean all joints and glazing pockets,
properties from DOWSIL 993 removing all foreign matter and
STANDARDS Structural Glazing Sealant it is contaminants such as grease, oil, dust,
DOWSIL 993 Structural Glazing recommended that the base and curing water, frost, surface dirt, old sealants,
Sealant combines excellent unprimed agent are thoroughly mixed using an or glazing compounds and protective
adhesion to a wide range of building airless mixing system found on most coatings.
substrates with high levels of physical existing commercially available two-
properties over a wide range of part silicone dispensing machines.
temperature. It exhibits excellent Metal, glass and plastic surfaces
Only special, two part hand mixed should be cleaned by mechanical or
retention of adhesive and mechanical cartridge systems endorsed by The
properties after ageing as detailed by solvent procedures. Where used,
Dow Chemical Company should be solvent should be wiped on and off
the EOTA Technical guide: used to avoid incorporation of air into with clean, oil- and lint-free cloths.
the material.
• 1000 hours exposure to ultraviolet
Priming
radiation in hot water immersion
DOWSIL 993 Structural Glazing Priming is not usually required when
(ISO DIS 11431)*
Sealant should be mixed in a ratio of using DOWSIL 993 Structural
• Resistance to salt spray 10:1 base to curing agent by weight, Glazing Sealant. However, it is
(ISO 9227 NSS)* or equivalent 7.8:1 by volume for essential that adhesion be tested prior
• Resistance to SO2 (ISO 3231)* optimal properties. At this mix ratio, to use. Specific primer
• Resistance to extreme temperature the sealant typically exhibits a recommendations will be made by the
(ISO 8339)* working time of 10–30 minutes and technical services department on a
allows units to be handled within two project basis. Please contact your
*
CE Marked as structural glazing hours. Small variations in mixing ratio representative for further advice.
sealant component according to can be tolerated, but these should not
ETAG002, the European Technical exceed 11:1 to 9:1 by weight or 8.9:1 Masking and tooling
Guidelines for structural glazing with to 7.3:1 by volume to ensure minimum Areas adjacent to joints may be
a level of attestation of 1. (external properties are obtained. masked to ensure a neat sealant line.
quality audit) valid in all EC
Do not allow masking tape to touch
countries.
Lot matching of DOWSIL 993 clean surfaces to which the silicone
* Structural Glazing Sealant Base and sealant is to adhere. Tooling should be
Meets structural glazing sealant DOWSIL 993 Structural Glazing completed in one continuous stroke
requirements according to EN13022, Sealant Curing Agent is not required. within 5 minutes after sealant
SNJF VEC + VI VEC. Before use it is recommended that the application. Masking tape should be
curing agent be stirred to ensure removed immediately after tooling.
homogeneity of all components.
DOWSIL 993 Structural Glazing Equipment cleaning
Sealant Curing Agent will react with When not being used it is
atmospheric moisture and therefore recommended that the dispensing
should not be exposed to air for equipment be purged either with the
HOW TO USE
prolonged periods of time. base component, or flushed with a
DOWSIL 993 Structural Glazing
Sealant offers unprimed adhesion to suitable solvent such as
Different catalysts are available for DOWSIL™ 3522 Concentrated
most coated and uncoated glasses as
well as most metal spacers. The DOWSIL 993 Structural Glazing Cleaning Solvent. If cured sealant has
sealant is compatible with DOWSIL™ Sealant: built up inside the equipment, flush
neutral curing construction sealants • DOWSIL 993 Structural Glazing the equipment for the appropriate time
such as DOWSIL™ 791 Silicone Catalyst is a medium viscosity with DOWSIL 3522 Concentrated
Weatherproofing Sealant, and paste, fast cure, which is suitable Cleaning Solvent, using a solvent
DOWSIL™ neutral curing insulating for meter mix equipment using a recirculation system. This solvent
glass sealants such as DOWSIL™ pressure pot or follower plate dissolves cured silicone sealant and
3362 HD Insulating Glass Sealant, as system for the catalyst. provides optimum cleaning
well as most commonly used glazing • DOWSIL™ 993 HV/GER performance.
components. It is important when Structural Glazing Catalyst is a
selecting components for a project that viscous paste, fast cure, which is
adhesion and compatibility tests are suitable for meter mix equipment
carried out, and found to be that uses a follower plate system
successful, before the project starts. for the catalyst.

UNRESTRICTED – May be shared with anyone

®
™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
DOWSIL™ 993 Structural Glazing Sealant
© 2017 The Dow Chemical Company. All rights reserved. Form No. 62-0918-01 N
2
MAINTENANCE Beside black and clear, the curing TO THE FULLEST EXTENT
No maintenance is needed. If sealant agent is offered in a variety of gray PERMITTED BY APPLICABLE
becomes damaged, replace damaged shades. Custom colors may be LAW, DOW SPECIFICALLY
portion. DOWSIL 993 Structural available on request. DISCLAIMS ANY OTHER
Glazing Sealant will adhere to EXPRESS OR IMPLIED
compatible cured silicone sealant LIMITATIONS WARRANTY OF FITNESS FOR A
which exhibits a clean knife-cut or This product is neither tested nor PARTICULAR PURPOSE OR
abraded surface. represented as suitable for medical or MERCHANTABILITY.
pharmaceutical uses.
DOW DISCLAIMS LIABILITY
HANDLING FOR ANY INCIDENTAL OR
PRECAUTIONS HEALTH AND
CONSEQUENTIAL DAMAGES.
PRODUCT SAFETY ENVIRONMENTAL
INFORMATION REQUIRED FOR INFORMATION www.consumer.dow.com
SAFE USE IS NOT INCLUDED IN To support customers in their product
THIS DOCUMENT. BEFORE safety needs, Dow has an extensive
HANDLING, READ PRODUCT Product Stewardship organization and
AND SAFETY DATA SHEETS a team of product safety and
AND CONTAINER LABELS FOR regulatory compliance specialists
SAFE USE, PHYSICAL AND available in each area.
HEALTH HAZARD
INFORMATION. THE SAFETY For further information, please see our
DATA SHEET IS AVAILABLE ON website, www.consumer.dow.com or
THE DOW WEBSITE AT consult your local representative.
WWW.CONSUMER.DOW.COM,
OR FROM YOUR DOW SALES LIMITED WARRANTY
APPLICATION ENGINEER, OR
DISTRIBUTOR, OR BY CALLING
INFORMATION – PLEASE
DOW CUSTOMER SERVICE. READ CAREFULLY
The information contained herein is
offered in good faith and is believed to
USABLE LIFE AND
be accurate. However, because
STORAGE conditions and methods of use of our
When stored at or below 30°C, products are beyond our control, this
DOWSIL 993 Structural Glazing information should not be used in
Sealant Curing Agent has a usable life substitution for customer’s tests to
of 14 months from the date of ensure that our products are safe,
production. effective, and fully satisfactory for the
intended end use. Suggestions of use
When stored at or below 30°C, shall not be taken as inducements to
DOWSIL 993 Structural Glazing infringe any patent.
Sealant Base has a usable life of 14
months from the date of production. Dow’s sole warranty is that our
products will meet the sales
PACKAGING specifications in effect at the time of
INFORMATION shipment.
DOWSIL 993 Structural Glazing
Sealant Base is available in 250 kg Your exclusive remedy for breach of
drums and 20 liter pails. such warranty is limited to refund of
purchase price or replacement of any
DOWSIL 993 Structural Glazing product shown to be other than as
Sealant Curing Agent is available in warranted.
25 kg pails.

UNRESTRICTED – May be shared with anyone

®
™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
DOWSIL™ 993 Structural Glazing Sealant
© 2017 The Dow Chemical Company. All rights reserved. Form No. 62-0918-01 N
3
Application Examples Figure 2: Section DD: 4-sided Figure 4: DOWSIL™ 993
Design – supported insulating glass Structural Glazing Sealant –
Figure 1: System for 4 sided unit. Snaptime range.
structural glazing.

Legend
1. Insulating glass unit
Figure 1A: Section CC: 4-sided 2. Silicone structural seal (DOWSIL™ 993
Structural Glazing Sealant)
Design – unsupported glass. 3. Silicone rubber spacer block
4. Silicone setting block
5. Aluminium profile
6. Backer rod
7. Structural sealant width dimension
8. Structural sealant bite dimension
9. Weatherseal dimension
10. Silicone weatherseal (DOWSIL™ 791
Silicone Weatherproofing Sealant)
11. Silicone insulated glass seal

Figure 3: DOWSIL™ 993

Structural Glazing Sealant – Tack-
free time range.

Figure 1B: Section DD: 4-sided

Design – unsupported glass.

®
Trademark of The Dow Chemical Company Form No. 62-0918-01 N
4