Sika® Aktivator 205 is a special adhesion promoting solution for the pre-treatment of bonding surfaces prior to bonding or sealing with Sikaflex® products — especially their 500 Series Hybrid Polyurethanes.
It is most often used as a required pre-treatment for Sika Primers - in applications where they are recommended or required - to make them adhere better to the substrate.
However, Aktivator 205 may also be used all by itself as a pre-treatment almost any time you use a Sikaflex® polyurethane adhesive sealant to enhance its bonding and long-term performance — by years, in many cases. See below for exceptions and further details.
Well worth the price, especially since it's relatively inexpensive for the benefits you get.
Comparing Aktivator 205 to the similar Aktivator 100
When using the traditional 200 Series of Sika® polyurethane adhesive sealants Aktivator 100 is the preferred choice for a somewhat larger range of appropriate substrates than Aktivator 205, but there is a high degree of overlap between these two Aktivators — so in many cases either one can be used.
Although either Aktivator can be used as a pre-treatment for plastic windows (acrylic/Plexiglas® or polycarbonate/Lexan®)...
Caution — Aktivator 205 CANNOT be used with mineral glass windows (frameless/direct glazing).
Some substrates for which Aktivator 205 is preferred, however, include rolled coatings, hard PVC and ABS plastics.
Perhaps most importantly, Aktivator 205 is the only Aktivator recommended one for use with Sika's Series 500 Hybrid Polyurethane Adhesive Sealants.
Areas of Application
Sika Aktivator 205 improves adhesion Sika polyurethane adhesive sealants and provides a more weather-resistant and longer lasting bond or seal on a variety of substrates. Particularly these are metals, many plastics, many types of paint and lacquer finishes.
It can be used by itself, or can be used prior to the application of an appropriate primer for even better adhesion and a longer service life.
Using Aktivators 100 or 205 typically leads to a more tenacious bond of your adhesive sealant — both initially and years later, after continued exposure to sun, moisture, and temperature variation.
With most substrates, scuffing the surface with an abrasive pad will yield even better results.
A Caution...
For critical applications and all glazing, Aktivator 100 or 205 should always be followed by the use of a substrate-appropriate primer before applying your adhesive sealant.
When applying adhesive sealants in critical applications, it is important to take into account the type of surface being bonded, as well as the surface being bonded to. You may decide to use one primer system for one, and a different primer system for the other.
For more specific information about bonding various materials and substrates, we urge you to refer to Sika's Primer & Pre-Treatment Charts for traditional 200 Series Polyurethane Adhesive Sealants, or for the newer 500 Series Hybrid Polyurethane Adhesive Sealants.
Especially, read over the notes for individual substrate types on page 4 of the chart.
In these Primer charts, following the recommendations in the more stringent Column 2 for critical applications will yield the most predictable results.
Within each substrate type, the first (higher up) recommendations are preferred.
Note that substrate PMMA/PC represents plastics such as acrylics and polycarbonates.
Some usage tips:
• Aktivators 100 or 205 are required as a pre-treatment in virtually all applications where any Sika Primer is used (wood is an exception)
• Do not use Aktivator 205 or the automotive industry Aktivator PRO as a substitute for Aktivator 100 in marine mineral glass applications; use only Aktivator 100 (with the orange cap) on mineral glass
• Do not use either Aktivator 100 or 205 on porous surfaces as they may not dry completely - preventing the adhesive or sealant from curing properly
• Aktivators 100 and 205 will not aid adhesion to UHMW, polyethylene, polypropylene, nylon, or other low surface energy (water beads up) surfaces
When applying Aktivators 100 or 205 —
• Substrate must be clean, dry, free of oil and grease and of sound quality. Thoroughly remove all loose particles and residues. Clean surface with a strong jet of oil-free compressed air or wash with acetone.
• Wipe on a thin layer of Aktivator using a lint-free cloth or wiper, then wipe it off with a lint-free dry towel and let it react for at least 10 minutes to allow adhesion promoters to work, then apply your primer or adhesive sealant
• Consumption will depend the nature of the substrate and your technique
• The open range to apply primer or adhesive sealant is 10 (>60°F) to 30 min (<60°F) with a maximum of 120 minutes; Aktivators 100 and 205 can be re-coated if you miss your application window
• Reseal container tightly immediately after use
• This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed to ensure adhesion and material compatibility
• Shelf life is 12 months in unopened container
Heavy on the technical side...
Sika Aktivators and Primers cure via exposure to moisture in the air (humidity).
Once opened, the cap should be replaced after each use. Do not leave the can open unless you are actually using it.
With frequent use i.e. opening and closing several times, Sika recommends disposing of the product one month after opening. With infrequent use, Sika recommends disposing of the product 2 months after opening.
If the Aktivator in the can turns cloudy or does not pour like water, it has been exposed to excessive moisture and should be replaced.
Sika Aktivators are manufactured in accordance with ISO 9001/14001 quality assurance system and the Responsible Care Program.
Click here for additional information and technical data about this product.