GMW GMW16292 PDF

This specification details the physical properties and performance requirements for weldable, preformed sealers that expand and cure in the Paint Shop Electrocoat (ELPO or E-Coat) oven.

These materials are intended to seal body joints from water, dust, and air intrusion. These materials shall be capable of being welded through.

Note: Due to new Electrocoat oven design, “2 step”, an additional lower temperature hold is required. Temperature and time could impact the performance of preformed body shop expandable sealers; therefore, in addition to the testing completed in this specification (specifically see 3.2.1), all preformed body shop sealers need to be tested at the target plant and in target locations of a vehicle to verify proper expansion and performance prior to launch.

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose/Material Description.

Weldable, preformed sealers are intended for use between two (2) pieces of oily metal that will be welded through. After application and welding, the material is processed through pretreatment and ELPO baths, and then baked in the ELPO oven. These materials are typically tacky throughout and may be referred to as “two-side tacky” or “T2.” A thin, dry film may be applied to one surface of the tacky, preformed sealer to improve the handling or weldability of the part, and the resulting composite sealer may be referred to as “one-side tacky” or “T1”.

The material has low-expansion capability, per Table 2, and cures upon heating in the Paint Shop Electrocoat (ELPO) oven.

The part may be applied in the Assembly Plant Body Shop, Metal Fabrication, or other sub-assembly sites. After application and welding, the assembled Body-in-White (BIW) is processed through the Paint Shop Pretreatment and ELPO baths, and then baked in the ELPO oven.

It shall not have a noxious or toxic odor in either the uncured or cured state.

In addition, the material shall not adversely affect the personnel handling it.

The material shall adhere to all GM globally approved metal substrates. The material shall be compatible with GM globally approved metal-forming lubricants and shall not cause defects in the phosphate, thin film, or E-Coat layers.

Symbols.

Not applicable.

Applicability.

Applicable to preform sealer materials that are formed into parts and installed prior to the assembly Plant Paint Shop, between two (2) layers of metal.

Remarks.

These materials are not intended to be fuel resistant and are not intended to be applied in the Paint Shop.

Submission Package.

A submission package shall be submitted for final approval of a material to this specification. The submission package shall contain a submission letter, product data sheet, panel preparation data, test data and results, bake charts. Test panel performance shall be photographically documented, able to be transferred electronically, and retained with the submission package.