Product Information
Construction
Dow Corning® 798 Cold &
Cleanroom Silicone Sealant
FEATURES Low modulus neutral silicone sealant
Neutral alkoxy cure system
100% silicone polymer APPLICATIONS
Mildew resistant Dow Corning® 798 Cold & Cleanroom Silicone Sealant is specifically
Bacteriostatic sealant formulated for sealing areas in refrigeration units and coldrooms. It is a one-
Low modulus, high elasticity part neutral curing silicone sealant, suitable for use in either interior or exterior
Low odor applications where joints are susceptible to mildew. It is a bacteriostatic
Conforms to ISO 11600-F&G- sealant, better protected against the bacterial growth. Dow Corning 798
25LM Silicone Sealant offers good adhesion to most porous and non-porous surfaces
Resistant to ozone, ultra-violet including masonry, tiles, aluminum, PVC-U, polyacrylate, polycarbonate,
radiation and temperature extremes glass and glazed surfaces.
TYPICAL PROPERTIES
Specification Writers: These values are not intended for use in preparing
specifications. Please contact your local Dow Corning sales office or your Global
Dow Corning Connection before writing specifications on this product.
Test method* Property Unit Value
Cure system Neutral
Application temperature ºC +5 to +40
ºF +41 to +104
CTM97B Specific gravity g/ml 1.51
CTM364C Extrusion rate g/minute 200
CTM98B Skin-over time (23ºC or 73ºF, minutes 20
50% R.H.)
CTM95A Tack-free time (23ºC or 73ºF, minutes 30
50% R.H.)
CTM663A Cure rate (23ºC or 73ºF, 50% R.H.)
1 day mm 2.0
3 days mm 4.0
2mm thickness S2 dumb-bells (ISO 37)
CTM137A E-Modulus 100% MPa 0.45
CTM137A Tensile strength MPa 1.9
CTM137A Elongation at break % 700
12x12x50mm size T.A. joint (ISO 8339/DIN2-8339)
CTM677 E-Modulus 100% MPa 0.35
CTM677 Tensile strength MPa 0.75
CTM677 Elongation at break % 380
CTM99E Hardness (Shore A) 29
Elastic recovery % >90
ISO 9047 Joint movement capability 25
* CTM: Corporate Test Method, copies of CTMs are available on request.
DIN: Deutsche Industrie Norm.
ISO: International Standardisation Organisation.
TECHNICAL Back-up materials Figure 1: Deep joint.
SPECIFICATIONS AND When back-up material is required,
closed cell polyethylene backer rod is
STANDARDS recommended. Low tack polyethylene
Conforms to SNJF Category 1, tape should be used in joints too
ISO 11600-F&G-25LM. shallow to allow the use of backer rod.
Bacteriostatic performance has Back-up materials provide back
been tested to ISO 22196:2007 pressure and prevent three sided
for MRSA, E.Coli and adhesion that limits sealant movement
Salmonella and to ISO 846 for capability.
P.Aeruginosa.
Finishing
HOW TO USE The joint should be tooled within 5
Surface preparation minutes of application to ensure good Figure 2: Shallow joint.
Ensure that surfaces to be sealed are contact between the sealant and the
clean, dry, sound and free from frost, substrate. Tooling of the sealant also
release agents, old sealants and other gives a smooth, professional finish.
contaminants which could impair
adhesion. All non-porous surfaces Clean-up
should be cleaned and degreased by Excess sealant may be cleaned off
wiping with a suitable solvent such as tools and non-porous surfaces whilst
Dow Corning® R40 Universal in an uncured state using
Cleaner, on a clean oil-and lint-free Dow Corning R40 Universal Cleaner.
cloth before application of sealant. If sealant is misapplied to porous
Porous surfaces such as concrete, substrates, it should be left until just
brickwork, and mortar must be Figure 3: Fillet joint.
cured, and then removed by peeling,
mechanically cleaned using a steel cutting or other mechanical means.
brush, sanding disc or other Care should be taken not to damage
mechanical means. plastic or coated surfaces.
Note: When using any solvent, always Joint design
provide adequate ventilation. Avoid The sealant joint width should be
heat, sparks and open flames. Use designed to accommodate the
solvent resistant gloves. Observe and movement capability of the sealant.
follow all precautions listed on solvent When designing joints using
container label.
Dow Corning 798 Silicone Sealant,
Masking the minimum width should be 6mm.
Areas adjacent to the joints should be For joints between 6-12mm wide, a HANDLING
masked with tape to prevent seal depth of 6mm is required. For PRECAUTIONS
contamination of the substrates and to joints above 12mm wide, a width to Product safety information required
ensure a neat sealant line. Masking depth ratio of 2:1 should be used. In for safe use is not included. Before
tape should be removed immediately situations where fillet joints are handling, read product and safety data
after tooling. needed, a minimum of 6mm sealant sheets and container labels for safe
bite to each substrate is recommended. use, physical and health hazard
Priming For joint dimensions greater than information. The material safety data
For specific advice, please refer to the 25mm, please contact one of sheet is available on the Dow Corning
Dow Corning® Primers' Guide or Dow Corning's Regional Service website at dowcorning.com. You can
contact one of Dow Corning's Centers for technical assistance. also obtain a copy from your local
Regional Service Centers for technical Dow Corning sales representative or
assistance. Distributor or by calling your local
Dow Corning Global Connection.
Dow Corning is a registered trademark of Dow Corning Corporation.
We help you invent the future is a trademark of Dow Corning Corporation.
2010, February 10 XIAMETER is a registered trademark of Dow Corning Corporation.
Ref. No. 62-1005D-01 © 2010 Dow Corning Corporation. All rights reserved.
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USABLE LIFE AND For further information, please see our
STORAGE website, dowcorning.com or consult
When stored in cool, dry conditions your local Dow Corning
below 30ºC (86ºF) in the original representative.
unopened containers, Dow Corning
798 Silicone Sealant has a usable life LIMITED WARRANTY
of 12 months from the date of INFORMATION – PLEASE
production. READ CAREFULLY
The information contained herein is
PACKAGING offered in good faith and is believed to
INFORMATION be accurate. However, because
Dow Corning 798 Silicone Sealant is conditions and methods of use of our
supplied in 310ml cartridges, packed products are beyond our control, this
in boxes of 12. information should not be used in
substitution for customer’s tests to
LIMITATIONS ensure that our products are safe,
effective, and fully satisfactory for the
Do not use Dow Corning 798 Silicone
intended end use. Suggestions of use
Sealant on bituminous substrates,
shall not be taken as inducements to
substrates based on natural rubber,
infringe any patent.
choloroprene or EPDM or on building
materials and flexible plastics which
might bleed oils, plasticizers or Dow Corning’s sole warranty is that
solvents. Do not use Dow Corning 798 our products will meet the sales
Silicone Sealant in a totally confined specifications in effect at the time of
space because the sealant requires shipment.
atmospheric moisture to cure.
Your exclusive remedy for breach of
Dow Corning 798 Silicone Sealant is such warranty is limited to refund of
not recommended for use on purchase price or replacement of any
submerged joints or in joints where product shown to be other than as
physical abuse or abrasion is likely to warranted.
occur. Bleeding can occur on porous
substrates such as concrete, marble, DOW CORNING SPECIFICALLY
granite or other natural stones. On DISCLAIMS ANY OTHER
sensitive substrates, specific testing EXPRESS OR IMPLIED
should be carried out. Dow Corning WARRANTY OF FITNESS FOR A
798 Silicone Sealant is not PARTICULAR PURPOSE OR
recommended for structural glazing or MERCHANTABILITY.
insulated glazing applications.
DOW CORNING DISCLAIMS
This product is neither tested nor LIABILITY FOR ANY
represented as suitable for medical or INCIDENTAL OR
pharmaceutical uses. CONSEQUENTIAL DAMAGES.
We help you invent the future. ™
HEALTH AND
ENVIRONMENTAL dowcorning.com
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.
Dow Corning is a registered trademark of Dow Corning Corporation.
We help you invent the future is a trademark of Dow Corning Corporation.
2010, February 10 XIAMETER is a registered trademark of Dow Corning Corporation.
Ref. No. 62-1005D-01 © 2010 Dow Corning Corporation. All rights reserved.
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