Dow Corning
794 silicone sealant
Glazing and construction (previously DC 916)
DESCRIPTION TYPICAL PHYSICAL PROPERTIES Masonry, As above As above None
concrete required
Dow Corning 794 is a one- These values are intended for use in
component, clear, neutral curing preparing specifications. cleaned and degreased by wiping with
silicone sealant for use in glazing and Cure type Alkoxy a solvent on an oil and lint free cloth.
curtain walling applications. It has Suitable solvents may include acetone,
excellent adhesion to many porous Flow, sag or slump < 2,5 mm methyl ethyl ketone (MEK), or
and non-porous substrates. Extrusion rate, gr/min 230 methylated spirits.
Penetration 130 Note:
USES
(1/10 mm) (1) Before using solvents on plastic
• For weathersealing between Working time 10 minutes sheeting it is recommended to
aluminium, UPVC and wood door check that the solvent does not
Tack free time 20 – 40 min. attack or degrade the surface of
or window frames and most
common construction substrates. Skin over time 10 – 20 min. the plastic sheet.
• For glazing applications that (2) When using any solvent, always
Staining None provide adequate ventilation.
utilise polycarbonate sheeting.
• Ideal as mirror adhesive. Modulus at 100% 0,35 MPa Avoid heat, sparks and naked
elongation flames. Observe and follow all
precautions listed on solvent
FEATURES & BENEFITS Elastic recovery > 90% container label.
Cure time 24 hours
• 100% silicone rubber.
Back-up material
• Clear neutral curing silicone Movement capability + 50%
sealant. o o
Service temperature -50 C to +150 C abe duracord closed cell polyethylene
• Fast cure range backer rod is recommended as a back-
• Excellent adhesion to up material. Low tack polyethylene
polycarbonate. Hardness (Shore A) 25
tape should be used in joints too
• Excellent unprimed adhesion to Tensile strength 0,5 MPa shallow to allow a back-up material.
many porous and non-porous
construction substrates. Elongation at break 375%
Masking
• Excellent weathering Specific gravity 1,47
characteristics including Areas adjacent to the joints should be
resistance to ozone, UV radiation Colour Clear
masked with tape to prevent
and temperature extremes. contamination of substrates and
• Non-slump. SURFACE PROPERTIES ensure a neat sealant line. Masking
• No maintenance required. tape should be removed immediately
This table is a guide only
• Long service life. after tooling.
Substrate Surface Recom. Constr.
cleaning degrea- Primer
SURFACE PREPARATION ing Finishing
Anodised or Degrease Methylated None
Joint preparation mill finished remove all spirits, required The joint should be ´tooled´ within five
aluminium. loose isopropyl
particles alcohol
minutes of application to ensure good
Cleaning and dust. contact between the sealant and the
Treated hard As above As above None
substrate. Tooling of the sealant also
Ensure that all surfaces are clean, dry, wood, UPVC, required gives a smooth, professional finish.
sound and free from frost. Clean all polycarbonate
joints of release agents, water Stainless steel As above As above 1 200
repellants, dust, dirt, old sealants and NP
other contaminants that could impair Granite, marble As above As above Barrier
adhesion. Metal surfaces should be 84
Revision 9203
Karachi: Room No.1, Mezzanine Floor, Al-Hayat Chambers, A-7, Block-7/8, K.C.H.S. Tel: +92 21 4535898-99, Fax: +92 21 4558071
Lahore: 25-A, FCC, Syed Maratib Ali Road, Gulberg 4, Tel: +92 42 5763360 Fax: +92 42 5875384
BONDING / PRIMING PROTECTION ON COMPLETION • TT-S-001543A and TT-S-00230C
(COM-NBS) class A, ASTM
When used in conjunction with most As Dow Corning 794 is UV resistant specification C-920 type S, grade
common construction substrates, a and is suitable for internal and external NS, class 25.
primer is not required. use. No protection is required.
MIXING TEMPERATURE AND RELATIVE
HUMIDITY HEALTH & SAFETY
No mixing required. Use straight from
o o
cartridge. Application temperature: 0 C - +40 C Dow Corning 794 will release
methylethylketoxine (MEKO) when
COVERAGE MODEL SPECIFICATION curing.
Dow Corning 794 is alkoxy and
One-component, neutral cure, low should not be allowed contact with skin
Estimating sealant requirements and eyes. Avoid inhalation of fumes.
Linear metres per 310 ml cartridge modulus, mildew resistant silicone
for plastics and glass. The use of gloves, eye protection and
Width
(mm)
5 7 10 12 16 20 25 masks is advised. Splashes into eyes
The sealant will be Dow Corning 794, should be washed immediately with
5 12,4 10,5 6,0 5,5 4,0 3,1 2,5
a one-component neutral curing plenty of clean water and medical
7 - 6,0 4,5 4,0 3,0 2,2 1,5
silicone sealant applied in accordance advice sought.
10 - - 3,0 2,5 2,0 1,5 1,2
with the recommendations of abe
12 - - - 2,2 1,6 1,3 1,0 Construction Chemicals. The sealant Cured Dow Corning 794 is inert and
will meet the requirements of BS 5889 harmless.
JOINT DESIGN type A, TT-S-00230C and TT-S-1543A
class A (com-NBS) for building IMPORTANT NOTE
When designing joints using Dow sealants, ASTM C 920 Type S, grade
NS, class 25. This data sheet is issued as a guide to
Corning 794, the minimum joint width
the use of the product(s) concerned.
should be 6 mm. For joints between
PACKAGING Whilst abe Construction Chemicals
6 mm - 12 mm wide, a seal depth of
endeavours to ensure that any advice,
6 mm is recommended.
Dow Corning 794 is supplied in recommendation, specification or
For joints above 12 mm wide, a width
310 ml cartridges, in boxes of 12. information is accurate and correct, the
to depth ratio of 2:1 should be used,
company cannot - because abe has no
up to a maximum depth of 12 mm.
HANDLING & STORAGE direct or continuous control over where
For joint dimensions greater than
and how abe products are applied -
25 mm wide contact abe Technical
This product has a shelf life of accept any liability either directly or
Services Department.
12 months if kept in a dry cool place indirectly arising from the use of abe
in the original packaging. In more products, whether or not in accordance
APPLICATION with any advice, specification,
extreme conditions this period might
be shortened. recommendation, or information given
Cut the tip of the nozzle at the angle by the company.
required. Apply Dow Corning 794
from a caulking gun using sufficient LIMITATIONS
pressure to ensure adequate contact FURTHER INFORMATION
with sides of joint. The surface of the Dow Corning 794 should not be used
joint may be smoothed over with a little on substrates that bleed oils, Where other products are to be used
liquid soap and water to ensure good plasticizers or solvents. It is not in conjunction with this material, the
contact between the sealant and recommended for use with certain relevant technical data sheets should
substrate. plastics, particularly flexible plasticised be consulted to determine total
types. Dow Corning 794 is not requirements. abe Construction
recommended for structural glazing or Chemicals has a wealth of technical
CLEANING
insulated glazing applications. Consult and practical experience built up over
abe Technical Services Department years in the company’s pursuit of
Excess sealant should be cleaned off
for further advice in specific excellence in building and construction
tools and non-porous surfaces whilst in
applications. technology.
an uncured state. Sealant adhering to
porous surfaces should be left until just
cured and then removed by abrasion TEST COMPLIANCE
or other mechanical means. Care must
be taken not to discolour plastic Dow Corning 794 meets or exceeds
surfaces. the following specifications:
Tools, brushes and mixing equipment • B.S. 5889 type A.
should be cleaned immediately after • DIN 18 540-F.
use and before material has set with • DIN 18 545 Gruppe E.
abe super brush cleaner followed by • DIN 52 452 T4.
washing with soap and water.
• SNJF first category.
Revision 9203
Karachi: Room No.1, Mezzanine Floor, Al-Hayat Chambers, A-7, Block-7/8, K.C.H.S. Tel: +92 21 4535898-99, Fax: +92 21 4558071
Lahore: 25-A, FCC, Syed Maratib Ali Road, Gulberg 4, Tel: +92 42 5763360 Fax: +92 42 5875384
