Sika 206 G+P Primer for Glass Windows

Sika® Primers contain chemicals which improve the surface adhesion and long-term bonding between Sika polyurethane adhesive sealants and various substrates (glass, metals, fiberglass, etc.).
Highly recommended for all but the simplest bedding tasks.
Despite their seemingly high initial cost, use of primers can save you money in the long run by extending the life of an adhesive bond by many years.

Primer-206 G+P is a black, fast drying liquid primer specifically formulated for the treatment of bond faces in direct (frameless) glazing of mineral glass windows prior to the application of Sika polyurethane direct glazing adhesives such as Sika 296.

Sika's most widely used primer, 206 G+P will also provide maximum long-term adhesion to a wide range of substrate types for general purpose bonding with 1-part polyurethane adhesive sealants. See below for more details.

NOTE: You must first pre-treat bonding surfaces with Sika Aktivator 100, prior to using Primer 206 G+P. See Related Products, below.

Comparing Sika's two general purpose primers: 206 G+ P and Primer 210T —
Primer 206 G+P is faster drying and has improved adhesion compared to Sika Primer-210T, however...
Primer 210T is clear in color, which may have some aesthetic advantages if the finished bond line is visible, or if your application technique is messy.

Applying Primer 206 G+P
• Scuff non-glass surfaces, apply Sika Aktivator 100 following directions, and then brush on Primer-206 G+P
• Primer 206 G+P cures in only 10 minutes (allow additional drying time at cooler temperatures, or for porous substrates); test painted surfaces and plastics first
• Coverage varies with substrate, but typically is 6.7 ft²/fl oz (56 ft² per 250 ml can)
• Working temperature range 41°F - 110°F
• Shelf life 9 months from date of manufacture, in unopened can @ 50-75°F
• For critical applications it is best to pre-test for adhesion*

For more specific information about bonding specific substrates, 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.


Heavy on the technical side...
Testing with actual substrates and conditions is the best way to ensure adhesion, and material compatibility.

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.

Primer-206 G+P can be used to touchup pinchweld scratches, and also act as a corrosion inhibitor on metals.
It may also be used when a frit band is not available on the perimeter of the glass part to provide partial UV protection to the polyurethane adhesive used.

Primer 206 G+P is also used as a general purpose primer to promote adhesion between polyurethane adhesives and the following substrates:
• Primary recommended substrates:
- Plain Steel (use after Sika Aktivator 100)
- Bare Fiberglass (unsaturated polyester) (use after Sika Aktivator 100; scuffing may be necessary)
- ABS plastic

• Secondary recommended substrates (finely scuff surfaces first):
- Aluminum (plain) (Use after Sika Aktivator 100 or Aktivator 205)
- Aluminum (anodized) (Use after Sika Aktivator 100)
- Stainless Steel (Use after Sika Aktivator 100 or Aktivator 205)
- Galvanized Steel (Use after Sika Aktivator 100)
- 2-Part Paints (Use after Sika Aktivator 100; no scuffing necessary); test first
- Powder and E-Coats (Use after Sika Aktivator 100; no scuffing necessary); test first
- Fiberglass Gelcoat (Use after Sika Aktivator 100 (no scuffing required) or Aktivator 205)
- PMMA/PC (Use after Sika Aktivator 100; coarse scuff first)
- Glass (Use after Sika Aktivator 100; no scuffing required)
- Ceramic screen print (Use after Sika Aktivator 100; no scuffing required)

* A Simple Adhesion Suitability Test
For critical applications you must test the actual materials under actual application conditions to check for satisfactory adhesion.
The suitability of any product for any application ultimately rests with the user (you).
(Note that the following test does not take into account long-term environmental exposure effects that can cause bonds to eventually fail.)

From previous experience, or using Sika's Application Charts, select your best choice of aktivator, primer, and adhesive/sealant for the material you are bonding.

Prepare the surface, apply aktivator and primer, then apply a 1/4" bead of sealant to the substrate.
Let dry for 7 days.
Take a needle nosed pliers and try to pull the bead of adhesive off.
If you "unzip" it — your test has failed.
If you pull off chunks of sealant or destroy the substrate, your test has passed.

Refer to the linked documents for additional information and technical data about this product.