The role of a sealant is to create watertightness, airtightness as well as a barrier to harmful insects. It permits air barrier continuity in building envelopes. Some sealants can also act as an adhesive and can be used as control or expansion joints in some constructions.
The role of an adhesive is to assemble similar or different materials together. Some adhesives replace mechanical fastening systems, thereby preventing metal corrosion created by screw or rivet hole drilling. Adhesives also play a sealing role, allow elongation and compression movements, as well as improve the aesthetics of certain assemblies, such as transport vehicles.
Surface cleaning is a crucial step in the success of a durable assembly or caulking. There are several methods of cleaning. Ideally, surfaces should be cleaned no more than one hour prior to application of the adhesive or sealant to prevent further contamination. See the pdf instruction: Inspection and maintenance guide for Adseal silicone weatherseal joints
- Porous surfaces (masonry, acrylic coating): Porous surfaces must be cleaned by mechanical abrasion. The surface must be ground or brushed as necessary, and the dust must be blown off with oil-free compressed air. If there is any old sealant or adhesive remaining, remove with a blade or spatula and finish mechanically to return the surface to its original state.
- Non-porous surfaces (metals, plastics): Non-porous surfaces can be cleaned most of the time with a solvent such as 99.5% isopropyl alcohol: Adseal Cleaner 6003
- use the two-cloth method, which consists of washing the surface first with a cloth dampened with cleaner and then wiping with a second clean, dry cloth before the solvent evaporates. Change cloths regularly to avoid dirt accumulation. Avoid soaking a soiled cloth in clean solvent, otherwise this will cause contamination. Choose white cloths that do not retain dust or leave lint on substrates. Make sure to clean all surfaces that will be in contact with the sealant or adhesive. Allow the solvent to evaporate properly before applying the sealant or adhesive.
- Chemical abrasion: On some substrates, solvent cleaning may not be effective. In this case, it is necessary to proceed with chemical abrasion using an acid bath. This process is quite complex and is often performed by specialized companies.
- Corona, Plasma or Flame treatment: Polyethylene or polypropylene plastics often require flame, plasma or Corona treatment. Corona treatment is done directly on the plastic extrusion line. In the case of flame or plasma treatment, it is done directly on the production line prior to adhesive application. These treatments reduce surface tension allowing a permanent adhesion of substrates.
Backer rods prevent adhesion to 3 surfaces, thereby favoring natural movement of the sealant in addition to helping determine it’s required depth. If the use of a backer rod is impossible, the use of a non-stick tape is recommended. The sealant is available in different diameters and must be made of polyethylene. Choose a backerboard 25% to 50% larger than the joint width.
There are mainly 2 types depending on chemistry:
- Drying by evaporation (solvent or water)
- Thermoplastic sealant: This type of sealant dries through the evaporation of its solvent gives off a very strong odor for several days, even when used outdoors. There is great volume loss upon drying, they cannot be shaped, and they have a very short shelf life. These products can be painted.
- Acrylic latex sealant: This type contains water to varying degrees, and will therefore have less important volume loss. These products have a very limited water resistance, must be used for interior applications only and can be painted. There are 2 types of acrylic latex sealants:
- Those that can be sanded
- Those that are flexible
- Drying by polymerization: These sealants they dry by reacting with ambient humidity. This reaction time can vary depending on the sealant chemistry. Three families dry by polymerization and each are called elastomeric sealants:
- Silicone: Silicone is the most durable of all elastomeric sealants. Its lifetime can exceed 25 years. It has an exceptional resistance to ultraviolet rays and many chemical products, can be applied in temperatures below 0°C, but cannot be painted. Silicones can be used for industrial or construction applications. Two silicone examples are as follows: Adseal DWS 4580 and Adseal LM 4600
- Hybrid: Hybrid sealants include three different chemistries: MS, STPE or SPUR.These different chemistries generally behave in a similar way. They have a good resistance to ultraviolet rays, can be painted, and are mainly used for wood and composite coatings that will eventually need to be repainted. Hybrid sealants can be used for industrial or construction applications: Adseal DWSP 1940 and Adbond 1500
- Polyuréthane: Polyurethanes are organic elastomers. They have a shorter lifespan and a very low resistance to ultraviolet rays, as their flexibility is affected by the sun. This type of sealant is recommended for hidden or painted industrial applications: Adthane 1800
- Is it for indoor use?
- Is it for outdoor use?
- Will the sealant need to be painted?
- Is it for an area with vehicle or pedestrian traffic?
- Will it be immersed in water?
- Will it be for a joint with significant movement?
- Is it for a structural application, such as a curtain wall?
- Is it for a glass partition?
- Is it for a for clean room or food room (indirect contact)
- Kitchen or bathroom
- Transport vehicle
|Product||Interior||Exterior||Painted||Traffic||Immersion||Movement||Structural||Glass partition||Clean room or food processing||Kitchen and bathroom||Transport vehicle||HVAC|
|Adseal Production 4550||X||X||X(p)||X||X||X|
|Adseal DWS 4580||X||X||X(p)||X||X*||X||X|
|Adseal LM 4600||X||X||X(p)||X||X||X|
|Adseal Structural 4940||X||X||X||X*||X|
|Adseal Structural 4940HV||X||X||X||X|
|Adseal KB 4800||X||X||X**||X||X|
|Adseal DWSP 1940||X||X||X||X||X||X|
|Adseal CF 1070||X||X|
|Adseal DWM 1090||X||X|
p = pedestrian
* available in multiple colors
** available in translucent color only
ASTM International is an organization that writes and produces technical standards for materials, products, systems and services. These standards are used by all manufacturers in North America. Standards begin with a letter followed by numbers (e.g. ASTM C719).
The class of a sealant is determined by the ASTM C719 standard. It indicates the sealant’s ability to move, for example a class 50 indicates 50% elongation and 50% compression. Therefore a 0.5” joint will be able to elongate before rupturing up to 0.75” and compress down to 0.25”.
The ASTM C719 standard includes classes 12.5, 25, 35, 50 and 100/50. The more a joint must experience physical stress, the higher the class must be.
In many cases, a class 50 sealant such as our Adseal DWS 4580 is adequate and can be used.
Adseal DWS 4580 is a class 50 neutral curing silicone sealant that can be used in many construction or industrial applications that do not require painting.
The larger the building, the more important it will be to use a 100/50 class sealant like our Adseal LM 4600, which can withstand greater movement.
Adseal DWSP 1940 is a hybrid technology, rather than a 100% silicone sealant. Its polymerization occurs when it is in contact with ambient humidity. This product is strongly suggested for construction or industrial assembly applications that need to be painted.
Depending on different sealant technologies, life expectancy can range from 5 years to over 25 years.
Some sealants can accumulate dirt. They can be cleaned with a mild soap such as dish soap or any product used to clean windows. If the dirt is embedded in the sealant because of mold or other contaminants, it will be impossible to remove it.
Adseal KB 4800 anti-mould silicone is the ideal product for this application
On some acrylic baths, adhesion may varie. The use of a primer such as our Adseal Primer MK60095 is therefore necessary.
Carry out a preliminary test to determine the correct application method. Neutral curing silicones or hybrid sealants are not recommended for this application.
Yes by sealing it properly to avoid contact of the product with ambient humidity or to avoid evaporation in the case of solvent or water based sealants. Once opened, the shelf life may vary depending on several factors.
Due to the wide variety of substrates and substrate formulations (e.g. ABS), it is highly recommended that a test be conducted prior to sealant application to determine whether or not the use of a primer is required. If a primer is required, we suggest Adseal Primer MK60095
Structural silicone is mainly used for structural glazing (curtain walls) and architectural panels. This silicone is capable of withstanding high wind loads under various conditions. Structural silicone is mainly designed to bond glass to the aluminum structure of a curtain wall. It can be glued on 2 sides (horizontally or vertically) or on 4 sides. Please note that structural silicone should not be used as a sealant or an expansion joint.
Since the role of a sealant is to preserve the integrity of a building against bad weather (water, air and insects), it is essential to report any deficiency in the seals as soon as possible to avoid damage that is often much more costly than repairing defective sealant. To do so, a regular inspection is recommended to avoid unpleasant surprises. Consult the Inspection and maintenance guide for Adseal silicone weatherseal joints
Insulating wool can get wet and thus lose its insulating power, which is not the case with polyurethane insulating foam. Polyurethane foam, if installed properly, will conserve its properties for several years and therefore generate energy savings as well as keep you warm.
Depending on the time of year and the size of the building, the choice of insulation foam will vary. For example, in temperatures below 0°C, we recommend Adfoam Polar 1825, as it can be applied in temperatures as low as -25°C.
For larger buildings which will experience greater movement, we recommend Adfoam Flex 1865
This foam is one of the most flexible products on the market. It must be applied above 0°C.
Please note that all polyurethane insulating foams should never be installed above 35°C.
There are mainly two types of cans. The first uses a straw and is therefore harder to control for precise applications. The second is a can with an adjustable gun that can be screwed onto the can. This is much more precise and will allow you to conserve your can longer once you start.
The use of a can with a spray gun is strongly recommended, especially when applying on the perimeter of doors and windows. For beginners, adjust the gun pressure to the minimum so as not to apply too much. If ever there was not enough pressure during the first application, you can always apply a second layer. Fill the cavity to roughly 50% to avoid any overflow or distortion of doors and windows. The exterior part of the door or window should be closed and the application should be done from the outside to the inside. The film on the outside should remain intact to preserve its sealing capabilities. The overflow should ideally be towards the interior of the building. If there is an overflow, you can then cut it off.
Use our Adfoam Clean/500 cleaner to clean your tools as well as surfaces where spillage has occurred. Always verify the compatibility of the product in an inconspicuous place beforehand. Visible surfaces should be cleaned before a skin forms, otherwise it will be very difficult to clean properly. To clean guns, screw the cleaning can onto the application gun and rinse generously so that no polyurethane foam residue remains.
In order to preserve the flexibility of the weatherstripping, it is recommended that a coat of Adseal Lubricant 4000A2 be applied every year. This will help preserve flexibility of your weatherstripping for many years. Hinges and all moving parts should be lubricated at the same time with our Adseal Lubricant 4000A2.
Sealants should be cleaned before skin formation with a small amount of mineral spirit. Always check the compatibility of the mineral spirit with your substrate before use. If you wait too long before cleaning, it will be very difficult to remove traces of dry sealant.
The Adseal Production 4550 series neutral silicone is recommended for sealing joints in food and clean room environments:
However, a waiting period of 28 days is required following application before proceeding with any food or drug production.
It is a glass wall on commercial buildings. The glass is glued to an aluminum structure either on 2 sides (vertically or horizontally) or on 4 sides. It is therefore important that the sealant be strong enough to withstand significant wind loads that exterior buildings may be exposed to.
Certain neoprene or EPDM setting blocks may stain silicone sealant, especially if the silicone is pale. In order to avoid this issue, we recommend using silicone or pvc setting blocks, such as our Adseal setting blocks.
Yes, it is very important to remove any air bubbles that may have occurred during the application of a structural sealant. Doing so provides better support, as shaping ensures greater surface contact between the sealant and the substrate.
We recommend a silicone sealant designed for movement joints, such as our Adseal DWS 4580 series. Some glaziers prefer to use the same structural sealant in order to avoid product mixing. This is acceptable, but more expensive.
We recommend an ASTM C1521 adhesion test on site. Our technical representatives are available to help support you with this type of test.
We recommend waiting 28 days to permit complete sealant reaction and vulcanization and thereby avoid contamination.
The available warranty is applicable to the product only. No application warranty is offered, as this is not within Adfast’s control. The warranty duration varies by product and application. We invite you to consult one of our technical sales representatives for more information.
Adseal HT 4706-3 is used for applications requiring a continuous temperature resistance of 260°C (500°F) or an intermittent temperature resistance of 315°C (600°F).
Does the surface need to be humidified before applying the polyurethane foam?
When ambient humidity drops below 30%, surfaces must be humidified to ensure proper curing of the foam.
Yes, we recommend that the can be shaken for 30 seconds. This operation must be repeated regularly to ensure a good molecular foam structure.
We recommend 4 to 10 minutes between layers
We recommend 20 to 45 minutes, depending on the polyurethane foam. We strongly recommend that the foam be cut from the inside. This will keep the outside skin intact and maintain the seal.
A sandwich panel is an assembly of 2 or 3 different substrates such as wood & rigid insulation or wood & plastic.
Yes, Adbond 5645 or any of our other polyurethane adhesive formulations must be lightly dampened prior to assembly to maintain sufficient moisture and to properly cure the center of the panel. We recommend that a water mist be applied to the adhesive, representing 10% of the adhesive weight.