GMNA - 9985345
Sealant Compound, Anaerobic, Cup Plug
|Publication Date:||1 July 2017|
Material Description. A blue anaerobic dimethylacrylate polyester resin base liquid compound that solidifies by polymerization (not by solvent evaporation) into a tough plastic when confined between closely fitted metal surfaces. This material may be used on slightly oiled cadmium and zinc plated, black oxide, and phosphate and oil coated parts and still obtain satisfactory properties. For maximum properties, parts must be cleaned.
Symbols. Not applicable.
Applicability. This high viscosity, thixotropic material is intended for sealing cup plugs against engine coolant or oil. Material shall be capable of obtaining full retaining and/or locking strength with gap thickness to 0.10 mm diametral and seal with gap thicknesses to 0.25 mm using the ASTM D4562 or ISO 10123 static shear strength pin and collar tests. The material curing time may be substantially reduced with accelerators or heat.
Temperature Use Range. It is best suited for application where temperatures range from -54 °C to 150 °C. Low temperature performance is based on maintaining 50% or more of the original minimum static shear strength after 2 h exposure (measure in 30 s or less). The low temperature test is not required for this standard. The upper temperature limit is based on Table 3 aging requirements.
Remarks. The words must, shall or will as used in this document mean a mandatory requirement.
Application of the product outside its use category (retaining) as defined by GMW16800, 18.104.22.168 is strictly prohibited.
Preferential bonding to one surface (adhesive failure) can be an indicator of surface contamination or inactivity if the metal is different.
Use of automated application dispensing system equipment designed for this product provides a measured uniform liquid coating. Contact the product manufacturer for equipment recommendations.
Test Result Perspective. Steel pin and collar forms are used to establish and compare diametral gap limit, cure speed and strength between retaining compounds. Test this product on end use surfaces as the metal reactivity (see 1.4.2) and production surface cleanliness affecting cure speed and strength to gap may be different from the values in this specification.
Container Size. No anaerobic container is more than 1 L because pressure on the product in the container can cause curing. Do not transfer anaerobic into an unauthorized or contaminated container.
Dispensed Product Location on Detail Drawings. Cup plugs are generally a press fit, you need just enough to fill in the surface imperfections which is generally much less than most dispense systems or a manual system would apply. If there is a slip fit, then sufficient product must be dispensed to allow filling the gap. Prints must show the product placement bandwidth. The applied anaerobic bead should be properly placed to minimize the insertion length. The dispensed product must not be pushed or plowed more than 3 mm to 4 mm to reach the fully installed position. The heat from the interference will help to accelerate the curing of the product and a "pre-cure" situation could occur. Continuing to press forward/inward could cause shearing or galling which could lead to leakage. Normally the sealant is applied to the bore or inside diameter of the parts.
Reactive Surfaces. Anaerobics bond with active metal ions and cure in the absence of air. The following are very reactive; brass, copper, manganese, followed by active; aluminum, bronze, iron, nickel and steel. Inactive metals are annodized aluminum, cadmium, chrome finishes, Inconel, magnesium, plated parts, galvanized steel, stainless steel, titanium and zinc. Small percentages of copper or other active metals are added to inactive compositions to promote anaerobic curing.
Parts Washer System Residue. Borate and nitrate cleaning residues will retard bonding and cure. 1.4.8 Design Resource Information. For those with access to Global Document Management (GDM), see the Assembly, Sealing and Fastening Bill of Material (BOM) Level II, select Best Practices (standard parts and features), and open the Commonly Used Parts folder where the Cup Plug BOM is located. Make sure your cup plug and bore fits the intended material and design direction. Regarding best practices, the supplier shall work with the GM Design Responsible Engineer to comprehend this requirement.