05-07-2016, 03:01 AM
If you are working with shipping containers one of the most difficult things for people to accept is DON'T PAINT THE EXTERIOR.
Weathering steel or corten steel as its sometimes called is a special alloy where the rusty-appearing patina itself is what keeps the steel from rusting. If you try to paint over it or remove the patina and then paint over it, you are altering the chemical state of the steel and it will quickly oxidize (rust) all the way through. The only paint that should be on the container is the original manufacturers paint. The only exception would be if the container has been repaired, the welded areas may not have the same weathering resistance as the original steel.
If you have a container that has already been re-painted and its already flaking off you'll want to remove the paint as quickly as possible because water will get under the paint and eventually the container will start leaking. If the container has been damaged in this manner the only real fix is to put a roof over it. If you need to paint the container for whatever reason you'll need to keep an eye on it and maintain (repaint) the container frequently because now you're relying on the paint (instead of the steel) to keep the water out. We sold a 35 year old shipping container that had never been repainted and it was solid, our neighbor had a 10 year old container that had been re-painted and where water got under the paint on the roof the steel got ate through in just a few years and everything inside got wet and moldy.
I contacted the company who makes Snow Roof and inquired if it was safe to put on the roof of the container and they advised against it unless I had a way to ensure that water couldn't gather.
ETA: The neighbor's painted container had been painted by a container resale company who claimed they knew what they were doing, it wasn't a "home job".
Weathering steel or corten steel as its sometimes called is a special alloy where the rusty-appearing patina itself is what keeps the steel from rusting. If you try to paint over it or remove the patina and then paint over it, you are altering the chemical state of the steel and it will quickly oxidize (rust) all the way through. The only paint that should be on the container is the original manufacturers paint. The only exception would be if the container has been repaired, the welded areas may not have the same weathering resistance as the original steel.
If you have a container that has already been re-painted and its already flaking off you'll want to remove the paint as quickly as possible because water will get under the paint and eventually the container will start leaking. If the container has been damaged in this manner the only real fix is to put a roof over it. If you need to paint the container for whatever reason you'll need to keep an eye on it and maintain (repaint) the container frequently because now you're relying on the paint (instead of the steel) to keep the water out. We sold a 35 year old shipping container that had never been repainted and it was solid, our neighbor had a 10 year old container that had been re-painted and where water got under the paint on the roof the steel got ate through in just a few years and everything inside got wet and moldy.
I contacted the company who makes Snow Roof and inquired if it was safe to put on the roof of the container and they advised against it unless I had a way to ensure that water couldn't gather.
ETA: The neighbor's painted container had been painted by a container resale company who claimed they knew what they were doing, it wasn't a "home job".