First, we want to explain a bit about how the Salt Spray Test works. Coated panels are placed in a chamber and a salt spray is applied until the requested amount of hours is reached. Failure is subjective based on the requirements of the user of the coating. This means that some people may consider a coating to fail when the first blister is formed. Some may not consider it a failure until the panel is completely rusted.
We contracted an independent lab to run the ASTM B117 Salt Spray Test with the scribe variation. This variation calls for a scratch/scribe to be placed on the panel before it is placed in the salt spray chamber. This measures how well the coating prevents rust from creeping under the edge. This is a realistic test since coated parts can have an edge where the coating stops or where the coating becomes damaged. We requested that the test be run until significant rust was visible. The lab stopped the test at 498 hours after we reviewed the photos seen below. Product #1 is DuraCoat® Matte Black, Product #2 is Cerakote™ H-Series in Graphite Black.
The results seem fairly clear to us. Our opinion is that DuraCoat® shows less rust and overall damage from the salt spray but we’ll leave that for you to decide.