Once the container was welded in place we went right at the rust. Although our container was classified as “wind and water tight” when we bought it, it had dents and rust. There turned out to be a tiny hole in the roof; it was barely big enough to see light through but a tiny wet spot appeared on the floor after the first rain. A couple of generous sprays of Flex-Seal solved the problem easily.
The dents were fine by us, especially given the pandemic-related price increases for containers—a single-trip container would have been prohibitively expensive—but rust will get worse over time.
Before going about any grinding, we had to identify what to use to paint over the spots we ground down. After all, in muggy Mississippi the rust would sneak back in immediately if the steel weren’t treated right away. As with so many elements of construction using shipping containers, there are countless opinions as to the best approach. Online, we saw some people using phenomenally expensive marine-grade coatings and others using standard Rustoleum.
A consultation with our friend Jason, who owns City Paint & Glass in McComb, Miss., led us to PPG 4160 DevGuard Multiprime primer. At around $53 per gallon, it seemed a reasonable middle ground among all the products available. We bought it in white; since the whole house will be painted much later, there was no point in bothering to tint the primer now.
There were many spots to grind, especially on the raised edges next to small dents, so the grinding was a tedious task if not especially difficult. Sometimes a grinding disk made sense, sometimes we used a wire cup brush attachment on the grinder.
