General Guidelines Solutions for Facades Application of Sikasil

General Guidelines Solutions for Facades Application of Sikasil

General Guidelines
Solutions for Facades
Application of Sikasil®
Weather Sealants
January 2010 / Version 1
Application of Sikasil® Weather Sealants
Table of Content
Purpose and General Information
3
Introduction
3
1.
Areas of Application
3
2.
Design and Joint Dimensioning
4
3.
Application Limits
4
4.
Working Place Conditions
5
5.
Surface Pre-treatment
6
5.1 Sika® Cleaner-205
7
5.2 Sika® Cleaner P and Sika® Cleaner G & M 8
5.3 Sika® Primer-210 and Sika® Primer-3N
8
6.
Processing and Product Application
9
7.
Field Adhesion Test
© January 2010 / Version 1 / Sika Services AG
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Application of Sikasil® Weather Sealants
Purpose and General Information
This document contains recommendations and hints for the application of Sikasil® WS weather sealants and Sikasil® FS fire rated sealants. These guidelines are relevant for the following products:
•
Sikasil® FS-665
•
Sikasil® WS-305 CN
•
Sikasil® WS-355
•
Sikasil® WS-605 S
•
Sikasil® WS-655
•
Sikasil® WS-680 SC
The information herein is offered for general guidance only. These guidelines should be read in conjunction with the relevant Product Data Sheets. This document covers gen­eral recommendations,
for specific advice please contact the Techni­cal Service Department of Sika Business Unit Industry.
Introduction
Sikasil® WS-680 SC is a MS-sealant. All other mentioned Sikasil® WS and Sikasil® FS products are
neutral-curing silicone sealants with a high move­ment capability and excellent ad­hesion to a wide
range of sub­strates. The quality and durability of the sealant joint depends on various factors including the cleanness of the substrates, application of the sealant, joint dimensioning etc.
1.
Areas of Application
Product
Application/Special Property
Sikasil® WS-605 S
Weatherproofing sealant for glass facades and metal cladding.
Sikasil® WS-305 CN
Weatherproofing sealant for glass facades and metal cladding. Only
available outside of Europe.
Sikasil® WS-655
Weatherproofing sealant for glass facades and metal cladding.
With reduced non-streaking properties and reduced dirt pick.
Sikasil® WS-680 SC
Weatherproofing sealant for self cleaning glass.
Sikasil® WS-355
Weatherproofing sealant for natural stone applications
Non-staining.
Sikasil® FS-665
Fire rated sealant.
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© January 2010 / Version 1 / Sika Services AG
Application of Sikasil® Weather Sealants
2.
Design and Joint Dimensioning
Joints must be properly dimensioned as changes are no longer possible after construction or sealant
application, respectively. For optimum perfor­ma
­ nce the joint width should be designed accord­ing
to the move­ment capability of the sealant based on the actual expected movement. The minimum
joint depth is 6 mm and a width / depth ratio of 2:1 should be re­spected.
Picture 1: Joint design rules
Sika offers a comprehensive project service package including design reviews and joint dimensioning. For more information please contact the Technical Service Department of Sika Industry.
3.
Application Limits
Most Sikasil® WS and FS Sealants are compatible with each other, with other engineering silicone
sealants manufactured by Sika, and with SikaGlaze® IG sealants. For specific information regarding
compatibility between various Sikasil® and SikaGlaze® products please contact the Technical Service
Department of Sika Industry. All other sealants have to be approved by Sika before using them in
combination with Sikasil® WS and FS sealants. Where two or more different reactive sealants are
used, allow the first to cure completely before applying the next.
Do not use Sikasil®WS-605 S, WS-305 CN, WS-655, WS-680 SC and WS-355 on pre-stressed
polyacrylate and polycarbonate elements as they may cause environmental stress cracking (crazing).
The compatibility of gaskets, backer rods and other accessory materials with Sikasil® WS and FS
sealants must be tested in advance.
Joints deeper than 15 mm should be avoided.
The above information is offered for general guidance only. Advice on specific applications will be
given on request.
© January 2010 / Version 1 / Sika Services AG
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Application of Sikasil® Weather Sealants
4.
Working Place Conditions
Although Sikasil® WS / Sikasil® FS may be proc­essed within 5 to 40°C, the optimum application
temperature of the sealant (and the substrates as well) is between 15 and 25°C (60 and 75°F). If
Sikasil® WS / Sikasil® FS sealants have to be applied at low tem­peratures is has to be ensured that
the substrate sur­faces are free of condensed water or ice. It is recommended after cleaning to dry
the substrates carefully with a heat gun and then immedi­ately apply the sealant.
Please be aware of the fact that the curing speed of Sikasil® WS / Sikasil® FS depends on the air
humidity and temperature: the lower the air humidity and the temperature the slower the product
will vulcanise.
If Sikasil® WS / Sikasil® FS sealants have to be applied above 40°C, the Technical Service Department of Sika Industry should be consulted. Field adhesion tests (see Chapter 7) are recommended.
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© January 2010 / Version 1 / Sika Services AG
Application of Sikasil® Weather Sealants
5.
Surface Pre-treatment
Surfaces must be clean, dry and free from oil, grease and dust. Care must be taken not to contaminate cleaned surfaces during any phase of production. If contami­nation occurs, surfaces have to
be re-cleaned.
The following information is offered for general guidance only. Advice on specific pre-treatment meth­
ods based on laboratory adhesion tests will be given on request. Please note that with the exception
of clear float glass, Sika has to test the adhesion of weather sealants on a project-by-project basis
on production-run samples of the original materials used in the specific project. It is binding to use
the surface pre-treatment agents recommended in the laboratory report, otherwise the warranty for
the adhesion behaviour of Sikasil® weather sealants and fire rated sealants is null and void.
Substrate
Surface Pre-treatment
Float glass
(including tempered, toughened, laminated and tinted types)
Pyrolytically coated glass
Sika® Cleaner-205 or Sika® Cleaner P* or
Ceramic-coated (enamelled) glass
Sika® Cleaner G & M**
Stainless steel
Anodised aluminium
Polyester powder-coated aluminum
Sika® Cleaner-205
PVDF-coated aluminum
Sika® Cleaner-205
Concrete
Wire brush
and Sika® Primer-210 or Sika® Primer-3N
Natural stone
Brush and Sika® Primer-210 or
Sika® Primer-3N
* Sika® Cleaner-P only in cases where Sika® Cleaner-205 is not acceptable for aesthetic reasons
** Sika® Cleaner G & M in case of heavily contaminated substrate surfaces.
Please note:
Sika® Cleaner-205 is not a simple cleaning solvent but contains a bonding agent which forms an
activating film on the substrate surface. On some surfaces, for example on certain glossy powdercoated aluminium profiles, this film may be visible and change the appearance of the profile.
Therefore, it is important to treat and apply Sika® Cleaner-205 like a primer and to use masking
tapes in critical (visual) areas if necessary.
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Application of Sikasil® Weather Sealants
5.1 Sika® Cleaner-205
Sika® Cleaner-205 is applied as follows:
•
Moisten a clean, dry, oil-free and lint-free cloth or paper with the product and rub it
over the sur­face till no more dirt can be seen on the paper or the cloth. Make sure
to turn the cloth or paper to expose new surface, or replace it regularly in order to
avoid wiping residues back onto the surface.
•
Unlike ordinary cleaning agents, the surface treated with Sika® Cleaner-205
must not be dried subsequently with a cloth or paper!
•
Drying time: The required minimum drying times are as follows (depending on the
environ­mental conditions in the workshop):
•
10 minutes if temperatures are at least 5°C
•
5 minutes if temperatures are at least 10°C
•
2 minutes if temperatures are at least 15°C (if in doubt, please check with
the Sika Technical Service Department).
•
If cleaned (“activated”) parts are not bonded/sealed immediately, protect them
against subse­quent contamination.
•
Sealant/adhesive application should take place within 2 hours after the application
of Sika® Cleaner-205. Otherwise the procedure as described above has to be
repeated before bonding.
For more details about Sika® Cleaner-205 please refer to the most recent Product Data Sheet.
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© January 2010 / Version 1 / Sika Services AG
Application of Sikasil® Weather Sealants
5.2 Sika® Cleaner P and Sika® Cleaner G & M
Sika® Cleaner P and Sika® Cleaner G & M are solvent-based cleaning agents and applied by the
“two-clothes-method”:
•
Moisten a clean, dry, oil-free and lint-free cloth or paper with the solvent and rub it
over the sur­face. Make sure to turn the cloth or paper to expose new surface, or
replace it regularly, in order to avoid wiping residues back onto the surface.
•
Then dry the surface using a clean, dry, oil-free and lint-free cloth or paper.
Never allow the sol­vent to evaporate from the surface; otherwise dissolved
contaminants will be left behind.
•
Repeat these operations until no more dirt can be seen on the paper or cloth.
•
If you are not bonding the cleaned parts immediately, protect them against
subsequent contami­nation.
•
If more than two hours have passed since cleaning, always repeat the cleaning
process before bonding.
For more details about Sika® Cleaner P and Sika® Cleaner G & M please refer to the most recent
Product Data Sheets.
5.3 Sika® Primer-210 and Sika® Primer-3N
Sikasil® WS-355 non-staining silicone sealant for natural stone bonds extremely well to many different substrates even without primer. Nevertheless, for durable water proofing joints on natural
stones Sika recommends to use Sika® Primer-210 or Sika® Primer-3N. Sika® Primer-210 and Sika®
Primer-3N are primers, not cleaning agents.
•
Clean the stone surface from dust, dirt and loose particles.
•
In order to avoid a visible contamination, a masking tape should be applied on the
front surface, if necessary.
•
Pour a small amount of Sika® Primer-210 / Sika® Primer-3N into a clean container
and apply the primer with a brush in a thin layer. Never dip the brush into the
original primer packaging.
•
Once the primer has been ap­plied, it is essential that no more solvent gets onto
the surface and that there is no further contamina­tion.
•
Leave to dry for 30 minutes and then apply Sikasil® WS-355.
•
Apply sealants to primed surfaces latest within two hours.
For more details about Sika® Primer-210 / Sika® Primer-3N please refer to the most recent Product
Data Sheets.
© January 2010 / Version 1 / Sika Services AG
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Application of Sikasil® Weather Sealants
6.
Processing and Product Application
After suitable joint and substrate preparation, Sikasil® WS / Sikasil® FS sealants are gunned into
place. For backfilling it is rec­ommended to use closed cell, sealant com­patible foam backer rods e.g.
high resil­ience polyethyl­ene foam rod. If joints are too shallow for backing material to be employed, it
is recommended using a polyethylene tape. This acts as a release film (bond breaker), allow­ing the
joint to move and the sealants to stretch freely. For more information please con­tact the Technical
Service Depart­ment of Sika Industry.
Tooling and finishing
Tooling and finishing must be car­ried out within the skin time of the sealant. When tooling freshly
applied Sikasil® WS / Sikasil® FS press the sealant to the joint flanks to get a good wet­ting of the
bonding sur­face.
Cure Mechanism
Sikasil® WS / Sikasil® FS sealants cure by reac­tion with atmospheric moisture. The reaction thus
starts at the surface and proceeds to the core of the joint. The curing speed de­pends on the relative
humidity and the tem­perature (see diagram 1 below). Heating above 50°C to speed-up the vulcanisation is not advisable as it may lead to bubble formation. At low temperatures the water content of
the air is lower and the curing reaction proceeds more slowly.
Curing speed [mm]
10
35°C
50°C
23°C
8
8°C
6
4
50°C / 95% r.h.
35°C / 90% r.h.
23°C / 50% r.h.
8°C / 30% r.h.
2
0
0
2
4
6
8
Time [days]
10
Diagram 1: Typical curing speed of Sikasil® WS / Sikasil® FS sealants at various conditions
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© January 2010 / Version 1 / Sika Services AG
Application of Sikasil® Weather Sealants
Removal of Sikasil® WS / Sikasil® FS
Uncured Sikasil® WS / Sikasil® FS may be re­moved from tools and equipment with Sika® Remover-208
or another suitable solvent. Once cured, the material can only be removed mechanically.
Hands and exposed skin should be washed immediately using Sika® Handclean Towel or a suit­able
industrial hand cleaner and water. Do not use solvents!
7.
Field Adhesion Test
The field adhesion test is a qualitative screening procedure that may help to identify poor installation techniques used in the application of sealants and adhesives. This will include poor cleaning,
incorrect use of primer, which could include selection of an unsuitable primer or omitting to use a
primer when one is required, poor primer application or improper joint design. To evaluate the sealant adhesion on site, a simple hand pull test can be used at the job site.
Field adhesion testing should be documented. It is suggested that 5 tests for the first 500 meters
and one test per 500 meters thereafter are carried out. Alternatively one test per floor per elevation
can be undertaken after the initial 5 tests are carried out.
The hand pull test procedure is as follows:
•
Make a knife cut from one side of the joint to the other (perpendicular to the joint)
•
Make two cuts (parallel to the joint) from the horizontal cut approximately 75 mm
long, at both sides of the joint, making sure no damage is caused to the substrates
surfaces
•
Place a 25 mm mark on the sealant tab
•
Hold a 50 mm piece of sealant firmly just beyond the 25 mm mark and pull at a
90° angle.
•
Check the adhesion of the sealant to both substrates separately, even if they are
of the same material. This is accomplished by extending the vertical cut along one
side of the joint, checking adhesion to the opposite side, and then repeating for
the other surface.
•
Pass/fail criteria for each sealant should be used, 100% cohesive failure is
classified as a pass. If any signs of adhesive failure are observed then the sealant
manufacturer should be contacted and a more detailed examination undertaken.
For specific advice please contact your local Sika representative.
© January 2010 / Version 1 / Sika Services AG
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Application of Sikasil® Weather Sealants
•
Whilst undertaking the field adhesion test you should also inspect the quality of
the joint section removed. Check if the sealant completely fills the joint, no voids
or air bubbles are present and the sealant joint dimensions are in line with those
specified on the drawings. Contact your local Sika representative if you have any
concerns related to the sealant adhesion or the quality of installation.
•
Record the test results in a project log book so that the results can be included in
the project manual.
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© January 2010 / Version 1 / Sika Services AG
Application of Sikasil® Weather Sealants
Legal Notes
The information contained herein and any other advice are given
in good faith based on Sika‘s current knowledge and experience
of the products when properly stored, handled and applied under
normal conditions in accordance with Sika‘s recommendations.
The information only applies to the application(s) and product(s)
expressly referred to herein and is based on laboratory tests which
do not replace practical tests. In case of changes in the parameters
of the application, such as changes in substrates etc., or in case
of a different application, consult Sika‘s Technical Service prior to
using Sika products. The information contained herein does not
relieve the user of the products from testing them for the intended
application and purpose. All orders are accepted subject to our
current terms of sale and delivery. Users must always refer to the
most recent issue of the local Product Data Sheet for the product
concerned, copies of which will be supplied on request.
Sika Services AG
Business Unit Industry
Tueffenwies 16
CH-8048 Zurich
Switzerland
Tel. +41 58 436 40 40
Fax +41 58 436 54 07
e-mail: ctd@ch.sika.com
www.sika.com
© January 2010 / Version 1 / Sika Services AG
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