Rust prevention on cast-iron fountain
This isn't a paint question per say, but I'm thinking paint experts may have the most knowledge on this subject.
A couple of months ago we bought a cast iron fountain for our patio. The odd thing is, our sprinkler system doesnÂt use water from our water softener but our garden hoses do and we filled the fountain with a hose, which (we believe) caused rust to develop in and on the fountain. Anyway, weÂve purchased some naval jelly to remove the rust but weÂre not sure how to keep the rust from coming back other than to fill the fountain with un-softened water in the future. We donÂt particularly want to paint the fountain because we like the old-world finish on it (i.e. fake rust Â ironic, huh?) and it appears rust inhibitors are all oily, which wouldnÂt work well in a fountain that attracts birds.
DH is wondering if we can use polyurethane to protect the fountain, however, the only ones we found at HD seem to be meant for wood and donÂt mention they can be used on metal. I found a lacquer made by Rustoleum but it isnÂt meant to be used outdoors.
Thanks for any advice you can offer,