Intercept Material Salt-Fog Test
January 2002

Background:

·        Salt-fog testing based on ASTM B117 was performed for 308 hours (12 days, 20 hours).  The test involves exposing the specimens to a moist salt atmosphere containing 5wt.% salt content.  The chamber temperature is 95F.

·        The testing compared steel rods in bags of different materials, namely:

Ø      Intercept
Ø      Poly (clear)
Ø      VCI (blue tint)

Test Notes

·        The large VCI sample had noticeable liquid inside the bag and corrosion on the sample after 24 hours of testing.  This effect appeared to be greater than on the smaller VCI sample, possibly indicating that the larger sample bag was not sealed completely, though no indication of incomplete seal was obviously seen nor detected.

·        For future tests, it is suggested that each bag be sealed in the same manner (ie. Heat seal) if possible to ensure that all bagging materials are evaluated equally.  The two VCI samples were wrapped and taped for this test. 

·        Post-test, a small cut in the bottom of the Intercept bag was noticed.  For future tests, a thorough pre-test inspection of all bags is warranted to ensure that no openings exist for moisture penetration.

·        Pre-test signs of corrosion on most sample rods appeared to be fingerprints.  In the future, it is suggested that the samples be washed and handled with gloves prior to testing.

·        Follow-up concluded that the Intercept materials tested here were thinner than other available product, and thus was not ideally suited to a salt-fog exposure of this duration.

Conclusion:

The Intercept rod did show signs of corrosion after the testing exposure; however, its performance significantly surpassed those of the other bag materials.  This test is normally truncated after 7 days exposure, the test length was extended at the request of the customer in order to better determine end point.  The corrosion present on the Intercept sample indicated that corrosion possibly began after or during day 11.

Severe corrosion was initiated on the rods stored within the VCI bag during day 1 of testing.  Corrosion began on the sample in the plain polyethylene bag after day 2 of the testing protocol, approximately 48 hours.

Same sample, opposite sides
Intercept post-test: "Streak" of corrosion evident	Intercept post-test: "spot" of corrosion evident (may be associated with pre-test bare hand handling)

Parts arranged in salt-fog chamber.

Exposed VCI sample after 24 hours of testing.

available - how thick the coatings are. The thicker the coating, the longer the protection, on any substrate.