Customer Value Proposition:
Parker Chomerics CHO-SHIELD® 2000 Series electrically conductive coatings provide a corrosion resistant conductive surface coating on aluminum or composite substrates.
By reducing moisture penetration, CHO-SHIELD 2000 Series coatings offer corrosion protection for enclosure flanges which mate with particular EMI shielding gaskets.
These tough, urethane coatings offer a highly conductive interface which improves overall EMI shielding performance. When used as a coating on a composite or other non-conductive surface, they provide the conductivity necessary to achieve excellent shielding effectiveness while maintaining their electrical and mechanical stability in hostile environments.
CHO-SHIELD 2000-series coatings are three-part, copper- filled urethane coating systems which have been formulated with special additives and stabilizers to maintain their electrical stability even at elevated temperatures which prevent aluminum surfaces from corroding in high humidity and/or marine environments.
In addition, CHO-SHIELD 2001 and 2003 contain soluble chromates to minimize the effects of galvanic corrosion of the aluminum substrate, even in the event of a coating scratch.
Features and Benefits:
The CHO-SHIELD 2002 coating, mainly intended for composite substrates or as a 2001 repair coating, is chromate-free. CHO-SHIELD 2003 is a dark pigmented version of CHO- SHIELD 2001.
The CHO-SHIELD 2001 and 2003 coatings are designed to be used with CHO-SHIELD 1091 primer on chromate conversion coated (MIL-DTL-5541 Type I, Class 3) aluminum substrates. CHO-SHIELD 2002 is designed to be used with CHO-SHIELD 1091 primer on non-aluminum substrates such as MIL-P-18177 glass-filled epoxy composites and will typically deliver 0.1 ohm/square surface resistance when cured for 2 hours at room temperature 21°C (70°F) followed by 30 minutes at 121°C (250°F).
Three component urethane system
Corrosion resistant copper filler
Exceptional mechanical properties -65°C to 85°C
(-85°F to 185°F) including abrasion and scratch resistance.
Excellent chemical resistance, including jet fuel (JP8), hydraulic fluids and motor oil.
Pre-measured kit allows easy mixing of components in one container.
Significantly more cost effective than silver filled epoxies.
Protects aluminum and graphite composite airframes from corrosion.
No degradation of shielding effectiveness after 500 hours of salt fog.
CORROSION PROOF FLANGE DESIGN WITH CHO-SEAL® 1298 CONDUCTIVE ELASTOMER, EMI SHIELDING GASKETS
The combination of the CHO-SHIELD 2000 series of conductive flange coatings and CHOSEAL 1298 conductive elastomer gaskets can form a virtual corrosion proof EMI sealing system for aluminum enclosures. CHO-SEAL 1298 is a fluorosilicone elastomer filled with passivated silver-plated aluminum filler. Figure 1 shows this application for an aluminum enclosure. First, the aluminum flange is typically treated with a MIL-DTL-5541, Type I, Class 3, hexavalent chromate treatment, or alternatively with Type II, Class 3, trivalent, chromate corrosion treatment. Mask the middle area of the aluminum flange ( approximately half the gasket diameter width) where the CHO-SEAL 1298 conductive gasket will be attached. Apply CHO-SHIELD 1091 primer over the treated aluminum to ensure proper adhesion of the CHO-SHIELD 2000 Series coatings. After allowing the CHO-SHIELD 1091 to dry properly, apply the CHO-SHIELD 2000 series coating according to the instructions contained below in this document. The CHO-SHIELD 2000 coating is then masked while the non-conductive topcoat is applied to the aluminum enclosure. However, note that the topcoat must be overlapped onto the CHO-SHIELD coating as shown in Figure 1 to ensure that the CHO-SHIELD coating and aluminum interface is not exposed to moisture that could intrude under the coating. Note also in that when choosing a topcoat, that that the maximum temperature for the CHO-SHIELD 2000 coatings is 85ºC. Application Surface preparation has a significant impact on the corrosion resistance offered by the CHO-SHIELD 2000-series of coatings. CHOSHIELD 1091 primer should be used to ensure good adhesion of CHO-SHIELD 2000-series coatings on all substrates. CHO-SHIELD 1091 primer is a one-component, air-drying system, which cures at ambient temperatures.
Three Part Urethane
Stabilized Copper Soluble Chromate Salts
Surface Resistance (ohms/square)
0.1 ohm/sq. (Cure 1)
0.1 ohm/sq. (Cure 2)
0.3 ohm/sq. (Cure 3)
Shielding Effectiveness (dB)
Continuous Operating Temperature
-65°C to + 85°C ( -85°F to 185°F)