Gibson 50' Cabin Yacht tank removal and replacement.

[50Gibsondriver]

Hi. New to the site. I bought a 1990 Gibson Cabin Yacht about a year and a half ago. The freshwater tank let loose due to corrosion (aluminum tanks), and I'm replacing it (have it out of the boat already), but am afraid the blackwater tank will let loose soon enough, so want to replace it too, along with he lines to it. It is not clear to me as to how to remove the blackwater tank at first or even second glance. Anyone have any experience they could pass on to me?

I've also had two marine mechanics looks at it, and they don't know either.

The boat is on Lake Norfork, in NC Arkansas.

Thanks,
Kevin

[BananaTom]

I replaced a black water tank in Gibson 36, mine was located under the dining table which converted to bed. We removed the table, cut the floor, and removed the tank so I could measure it. The ordered a plastic tank, and once it arrived, installed it, which included cutting holes is the plastic replacement tank at the appropriate locations.

[50Gibsondriver]

BananaTom,

Thanks for the response. It looks like my blackwater tank is located directly under the stairs from the galley to the salon extending to under the refrigerator. I presently have no idea how I'm going to get it out without absolutely tearing up a lot of boat. Still working on it. Still no marine mechanics want to touch it, so looks like I'm gonna be on my own on this job.

[desimulacra]

I personally would just replace it as you plan but wanted to mention you can borrow or rent a good D-Meter and check the thickness of your tank. If you do establish the correct thickness from an area that doesn't have corrosion and then measure the tank in many different areas. If there is a greater than say a 25% variance, trash it. (Some might say up to 50% but that's pushing it as the corners cannot be checked.)

[50Gibsondriver]

Yes, planning to ditch the old tank and replace with new.

[50Gibsondriver]

I replaced a black water tank in Gibson 36, mine was located under the dining table which converted to bed. We removed the table, cut the floor, and removed the tank so I could measure it. The ordered a plastic tank, and once it arrived, installed it, which included cutting holes is the plastic replacement tank at the appropriate locations.

Who did you order your replacement black-water tank from?