Re: Survey found corrosion in mast
I know this post is old but just for the information: This type of corrosion is whats called filiform corrosion which is basically when water gets between the paint and the metal due to a scratch or ding in the paint. The aluminum starts to corrode because it cant re-passivate itself since its still under the paint and just corrodes from there. If the owner had seen the paint "bubbling" early, and stripped the paint the hole in the mast could have been prevented.
Also, this didnt happen from the mast having sitting water in it but water between the paint and the mast, probably due to a poor application of the paint or the preparation of the mast for paint. That being said, only the part of the mast that had the "bubbles" under the paint would need to be removed and assuming this hasn't happened anywhere else, the mast would be structurally fine. But a thorough inspection of the mast would need to be done since it was painted/prepped all at the same time.