[Gem930]

I’ve refurbished three other bays but not the tankage bay……yet!  My 2 cents worth would be por15 on all the metal, top and bottom, froth pack with a hose as Richard mentioned, then an epoxy resin water barrier.  Not sure how to work the resin along the tanks but it would provide much the same surface as original maintaining a watertight barrier.

Good job so far…

Check the integrity of the 12v water pump isolator, mine delaminated.  Replaced with rubber isolators. Another mod while in this bay would be to retrofit the waste tank valve with a pneumatic operator (matching the other valve) as it is really difficult to operate the manual gate at arms length.  It’s easy to add a spool valve since the air supply and 12v is already there.

Good idea on the pneumatic operator.  My wast was stick open, likely not closed in years.  Additionally both valves need the seals replaced.  Trying to source those today.