1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1988 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National Sta
4、ndardJ1969ISSUEDOCT88Issued 1988-10ELECTROCOAT COMPATIBILITIES OF AUTOMOTIVE SEALERSForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat.1. ScopeThis SAE Recommended Practice sets forth a method for determining the compatibility of automotivesea
5、lers with cathodic electrocoat primer.2. ReferencesThere are no referenced publications specified herein.3. Principal of MethodsThis practice sets forth two methods for evaluating what effect, if any, an automotivesealer has on an electrocoat primer bath or the resulting baked primer coating, or bot
6、h.Method #1 determines if a sealers passage through the bath will “leach out“ any material, from the sealer, thatwill then produce coating irregularities.Method #2 determines if a bath contaminated with sealer debris, 0.1% by weight, will have any effect on partsprocessed subsequent to the contamina
7、tion.4. Equipmenta. DC Power Source: 0600 V minimum and 010 Ab. One gallon plastic pails 155 mm (6 in) ID and 190 mm (7.5 in) highc. 7700 mm2 (12 in2) stainless steel Anoded. Laboratory Stirrer: 256 1200 rpme. Stirring Shaft: 460 x 13 mm (18 x 0.5 in) longf. Mixing Blades1. Dispersion: 75 mm (3 in)
8、standard stainless steel, high dispersion2. Agitation: standard stainless steel mixing propellerg. Sealant Applicator: opening in template is 25 x 1.5 mm (1 x 0.06 in)h. Oven: Gas fired or electric mechanical convection oven capable of obtaining 190 C (375 F) metaltemperature on CRS 0.81 mm (0.032 i
9、n) in 8 10 mini. Cathodic Electrocoat Primer: 2 gal, at least 24 h oldj. Steel Panels: 100 x 300 x 0.81 mm (4 x 12 x 0.032 in) zinc phosphatedk. Sealant to be testedSAE J1969 Issued OCT88-2-5. Sealant Panel Preparation5.1 Sealant should be conditioned for 24 h at 23 2C (73 4F) before use.5.2 Unless
10、freshly zinc phosphated, test panels should be dried at 120C (250F) for 6 min prior to sealantapplication to remove absorbed moisture.5.3 Using the sealant applicator template, apply a 100 x 25 x 1.5 mm (4 x 1 x 0.060 in) strip of the sealant to betested to the bottom half of one of the zinc phospha
11、ted panels. Start the bead 25 mm (1 in) from the bottom ofthe panel, see Figure 1.FIGURE 1SAE J1969 Issued OCT88-3-5.4 The sealant coated panel must be conditioned at 23 2C (73 4F) for no less than 4 h nor more than 24 hprior to being placed in the primer bath.5.5 Proceed to Section 6 while sealer p
12、anel is setting.6. Electrocoated Control Panel Preparation6.1 Fill a 1 gal plastic container, see Figure 2, within 2 in of the top with a sample of cathodic electrocoat primer.16.2 Condition a 100 x 300 x 0.81 mm (4 x 12 x 0.032 in) zinc phosphated panel as in 5.2.6.3 Electrocoat the panel at a prim
13、er thickness of 0.030 mm (0.0012 in) per the E-coat suppliers recommendationsor as defined in Appendix A.6.4 Bake the primed panel for 30 min at 182C (360F) or as specified.6.5 Examine the baked surface, on both sides, for surface irregularities and craters. Use the Crater Rating Systemlisted in App
14、endix B to grade the surface.6.6 If the surface of the primed panel is smooth and has a Crater Rating of 10, and only 102, label the panel as“A-1“ and retain as your standard for subsequent comparisons.7. Method I - Fresh Bath7.1 Place the sealer panel prepared in 5.3, after the designated condition
15、ing period, into the 10 rated primer from6.6. If the sealant is a die cut part, submerge the part in the bath, see Figure 2.7.2 Agitate the primer bath, with sealant submerged, for 16 20 hours.7.2.1 Agitate the primer bath with the propeller blade 25 mm (1 in) from the bottom with the mixer rpm cont
16、rolled toavoid foaming or spillage.7.3 Electrocoat the sealer panel at a minimum primer thickness of 0.030 mm (0.0012 in) per the E-coat suppliersrecommendations, or as defined in Appendix A.7.4 Bake the primed sealer panel for 30 min at 182C (360F) or as specified.7.4.1 Label the baked sealer panel
17、 as “A-2“.7.5 Electrocoat another zinc phosphated panel, as described and conditioned in 4.2, at a primer thickness of0.030mm (0.0012 in) as in 7.3.7.6 Bake the primed panel as in 7.4.7.6.1 Label the baked primed panel as “A-3“.1. Note - The primer should be at least 24 h old.2. Note - If the Crater
18、 Rating is less than 10, a new gallon of primer must be tested.SAE J1969 Issued OCT88-4-FIGURE 2SAE J1969 Issued OCT88-5-7.7 Examine both sides of panels “A-2“ and “A-3“ using panel “A-1“ as a standard.7.7.1 Note any film irregularities7.7.2 Count the total number of craters on both sides of each pa
19、nel and record the values.7.7.3 Assign the Crater Rating3 per Appendix B.8. Method II - Contaminated Bath8.1 Evaluate the quality of a second gallon of cathodic electrocoat primer as in steps 6.1 through 6.5.8.2 If the surface of the primed panel is smooth and has a Crater Rating of 10, and only 104
20、, label the panel as“B-1“ and retain as your standard for subsequent comparisons.8.3 Transfer the gallon of the 10 rated primer to a clean 1 gal container.8.4 Add three grams of the sealant to be tested to the primer bath. If the sealant is a die cut part, submerge thepart in the bath.8.5 Agitate th
21、e contaminated bath at high rpm with the dispersion blade for 1 h making sure the blade is 25 mm(1in) from the bottom of the container.8.6 Return the contaminated primer bath to the test container.8.7 Agitate the contaminated primer bath for 16 20 hours.8.7.1 Agitate the contaminated primer bath wit
22、h the propeller blade 25 mm (1 in) from the bottom with the mixerrpm controlled to avoid foaming or spillage.8.8 Electrocoat a 100 x 300 mm (4 x 12 in) zinc phosphated panel in the contaminated bath as described inAppendix A.8.9 Bake the primed panel for 30 min at 182C (360F) or as specified.8.9.1 L
23、abel this panel as “B-2“.8.10 Examine both sides of panel “B-2“ using panel “B-1“ as a standard.8.10.1 Note any film irregularities.8.10.2 Count the total number of craters on both sides of panel “B-2“ and record the value.8.10.3 Assign the Crater Rating5 per Appendix B.PREPARED BY THE SAE BODY SEAL
24、ER TASK FORCE OF THESAE ADHESIVES AND BODY SEALERS COMMITTEE3. Note - A Crater Rating of eight or higher is usually an acceptable value.4. Note - If the Crater Rating is less than 10, a new gallon of primer must be tested.5. Note - A Crater Rating of eight or higher is usually an acceptable value.SA
25、E J1969 Issued OCT88-6-APPENDIX ACOATING PROCEDUREA.1 Add cathodic electrocoat primer, aged at least 24 h before use, to within 2 in of the top of the 1 gal coating tank.A.2 Agitate the primer bath by means of the propeller stirrer.A.2.1 Speed of agitation should be limited to that necessary to caus
26、e moderate surface movement without creating avortex, which could cause foaming.A.3 Temperature of the bath should be maintained at 28C (82F) or as specified by the primer manufacturer.A.4 Attach panel to be primed to the cathode of the coating tank.A.5 Reduce agitation during the coating process to
27、 prevent the panel from moving while in the bath.A.6 Coat panel for 2 min at the voltage recommended by the primer supplier needed to achieve the desired filmthickness.A.6.1 Raise voltage from 0 to the recommended voltage over a 15 s period, ramp time.A.6.2 Maintain voltage, at the recommended volta
28、ge for 120 s and return to 0 V instantaneously.A.6.2.1 Decrease voltage if film builds are excessive.A.6.2.2 Increase bath temperature if film builds are insufficient.A.6.3 Wash coated panels with deionized water to remove undeposited paint.A.6.4 Air dry panels at ambient temperature or blow dry wit
29、h oil free air.A.6.5 Bake panels in an oven for 30 min at 182C (360F), or as recommended by the primer supplier.A.6.6 Evaluate the cured primer for surface imperfections.66. Note - While the bath is not in use, it should be kept covered to prevent evaporation and introduction of contaminants. A dirt
30、y oven may also affect finished film appearance.SAE J1969 Issued OCT88-7-APPENDIX BCRATER RATINGB.1 The following table sets forth a grading scale involving the total number of craters on both sides of a coatedpanel whose coating dimensions are 100 x 150 mm (4 x 6 in):TABLE B1Rating Numbers of Crate
31、rs10 None9 1 28 3 57 6 106 11 155 16 254 More3 than2 251SAE J1969 Issued OCT88RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Recommended Practice sets forth a method for determining the compatibility ofautomotive sealers with cathodic electrocoat primer.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Body Sealer Task ForceSponsored by the SAE Adhesives and Body Sealers Committee
