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BR® 6747-1 corrosion inhibiting primer is a one part, chromate based, modified epoxy primer which contains no volatile organic components (VOC).

BR® 6747-1 is 100% water-based and does not rely on exempt solvents to achieve its zero VOC level rating. It exceeds all state and federal VOC emission regulations for structural adhesive bonding primers and offers mechanical properties and corrosion resistance equal to that of solvent-based primer systems. In addition, BR® 6747-1 also provides outstanding performance with most 250ºF - 350ºF (121ºC - 177ºC) curing adhesive systems.

BR® 6747-1 offers wide application/processing latitude, simple processing with High Volume Low Pressure (HVLP) or standard air atomizing spray equipment and is insensitive to spray booth conditions - temperature from 65ºF - 90ºF (18ºC - 32ºC) and relative humidity from 30% - 70%. For applications which do not allow the use of chromate corrosion inhibitors, please see the Technical Datasheet for BR® 6747-1 NC non-chromate-based corrosion inhibiting adhesive bonding primer.
Unit of Measure

Specifications

Service Temperature

 N/A -67 to 350 ºF-55 to 177 ºC

Color

 N/A Yellow

Characteristics for Physical Properties (Liquid Primer)

Maximum Shipping/Transport Temperature at 35 Degree Fahrenheit (ºF) to 90ºF (2 Degree Celsius (ºC) to 32 Degree Celsius (ºC))

 N/A 15 days

Shelf Life

 N/A 12 months at 40ºF to 55ºF (4ºC to 13ºC) from date of shipment
6 months at 56ºF to 75ºF (14ºC to 24ºC) from date of shipment
DO NOT FREEZE

Maximum Shop Life at (75 to 90 ºF) (Degree Farhenite)

 N/A 30 days

Density for 20 Percent (%) Solids Content

 N/A 8.78 lb/gal1.05 g/cm³

Density for 30 Percent (%) Solids Content

 N/A 9.10 lb/gal1.09 g/cm³

Inhibitor

 N/A 15% Chromate (Based on Resin Solids)

Characteristics for Product Availability

Available Solids Content

 N/A 20 %30 %

Test Method for Solids Content

 N/A American Society for Testing and Materials (ASTM D 2369)

Size

 N/A 1.00 gal5.00 gal

Processing

Primer Storage

 N/A BR® 6747-1 may be stored at temperatures from 40 ºF to 55 ºF (4 ºC to 13 ºC) for up to 12 months, from 56 ºF to 75 ºF (13 ºC to 24 ºC) for up to 6 months and from 75 ºF to 90 ºF (24 ºC to 32 ºC) for up to 30 days. Specific care should be taken to prevent BR® 6747-1 from freezing or from being exposed to temperature below 32 ºF (0 ºC) and above 90 ºF (32 ºC).

Mixing

 N/A It is not necessary to warm the container to room temperature before opening. Thoroughly mix BR® 6747-1 upon opening and agitate during application.

Note for Mixing

 N/A During transportation and storage conditions the primer may form a layer of soft settling solids at the bottom of the can. It will take more mechanical force to disperse the solids from the bottom if the settling is densely packed. To increase mixing efficiency, we recommend using mixing beads to aid agitation or using a mechanical propeller blade to disperse the settling solids before putting into a shaker or roller machine.

Surface Preparation

 N/A A clean, dry, grease-free surface is required for bonding. BR® 6747-1 is used with standard cleaning techniques involving a four step procedure of solvent degreasing, alkaline cleaning, chemical deoxidizing (etching) and phosphoric acid anodizing (Boeing patent 4,085,012 April 1978. Phosphoric acid anodizing is now being used by a large number of aircraft manufacturers due to the improved surface bond durability it provides.). General guidance for etching and phosphoric acid anodizing can be found in ASTM D 2651 and ASTM D 3933, respectively. Best results for aluminum feature priming after appropriate surface preparation.

Equipment

 N/A BR® 6747-1 may be sprayed using a variety of equipment including hand-held, automated, conventional air-atomizing, HVLP or electrostatic spray equipment. Parts may be racked for spray and cured in any position convenient for the process.

Primer Thickness

 N/A Spray a dry primer thickness of 0.0001 to 0.0003 inches (0.0025 to 0.0076 mm) for optimum mechanical properties. Spray technique consists of applying smooth and even coats. The primer should be applied using two to three thin box coats (4-6 cross coats) to obtain the final film thickness. Additional coats of primer may be sprayed and cured onto previously cured areas without loss of properties.

Spraying

 N/A For uniform coating, apply one thin coat of primer to cover the entire part and allow to dry completely (primed portion color will change to lighter yellow when dry). Then spray additional box coats on top to achieve the desired primer thickness. Allow 30 to 60 seconds drying between each box coat.

Spray Gun Cleaning

 N/A If using a gun in which a solvent-based material has been used, the spray gun must be rinsed and sprayed for at least 1 minute with deionized water prior to loading the gun with BR® 6747-1 primer.

Clean the gun immediately after use by rinsing and spraying with deionized water.

Dry Time

 N/A 15 to 60 minutes at 75ºF (24ºC) and less than 55% relative humidity is recommended.

Primer Cure Cycle

 N/A Dry primer coatings are recommended to be cured at 250ºF (121ºC) for 60 minutes to obtain a surface which is scratch and MEK wipe resistant. The primer may also be cured at temperatures up to 350ºF (177ºC) for 60 minutes to obtain similar properties. Assemblies primed with BR® 6747-1 and then cured can be stored for six months and longer without degradation of the final bond strength. Assemblies that have been primed and cured should be protected from dust and oil by wrapping in protective sheeting such as Kraft paper. Stored assemblies should be wiped with a suitable solvent prior to bonding.

Bonding Cycles

 N/A BR® 6747-1 may be used with most epoxy based thermoset adhesives that cure between 250ºF and 350ºF (121ºC and 177ºC). Primed details may be exposed to up to three 60 minute 250ºF (121ºC) cure cycles with no significant loss of primer properties.

Spray Gun Settings for Accuspray Spray Gun (HVLP) Series 10

Fan Adjustment (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 1 Counter-Clockwise Turn

Fluid Control (Needle Adjustment Screw) (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 2 Counter-Clockwise Turns

Needle Size (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 0.036 in0.091 cm

Air Cap Model (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A #11

Cup Pressure (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 4 psi0.02 Map

Atomization Pressure (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 6 psi0.04 Map

Spraying Distance (Nozzle to Panel) (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 14 to 16 in36 to 41 cm

Room Temperature (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 70 to 90 ºF21 to 32 ºC

Humidity (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A < 65 %

Minimum Air Supply Pressure (Accuspray Spray Gun (High Volume Low Pressure (HVLP)) Series 10)

 N/A 80 psi0.55 Map

Spray Gun Settings for Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531

Fan Adjustment (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 1 Counter-Clockwise Turn

Fluid Control (Needle Adjustment Screw) (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 1/2 - 3/4 Counter-Clockwise Turns

Needle Size (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 0.034 in0.086 cm

Air Cap Model (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 46 MP

Cup Pressure (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 4 psi0.02 Map

Atomization Pressure (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 38 psi0.26 Map

Spraying Distance (Nozzle to Panel) (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 14 to 16 in36 to 41 cm

Room Temperature (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 70 to 90 ºF21 to 32 ºC

Humidity (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A < 65 %

Minimum Air Supply Pressure (Devilbiss Spray Gun (High Volume Low Pressure (HVLP)) Model JGHV-531)

 N/A 80 psi0.55 Map

Features and Benefits

Features and Benefits

 N/A
  • Zero V.O.C., 100% water-based
  • MEK wipe resistant after 60 minute cure at 250ºF (121ºC)
  • Can be cured from 250ºF to 350ºF (121ºC to 177ºC)
  • Excellent corrosion resistance
  • Approved primer for AC-® 130 bonding prep process (Boeing's patented sol-gel technology)
  • Recommended use with FM® 73M, FM® 87-1K, FM® 300K, FM® 300-2M, or FM® 377S

Additional Information

Additional Information

 N/A Typical applications for BR® 6747-1 include bond primer for aluminum components where corrosion protection is critical, corrosion inhibiting paint primer for aluminum substrates, and effective adhesion promoter for other metals (stainless steel, titanium, and nickel).