[Gem930]

I can’t be the only person you have ever had to deal with this, but I’m having a hard time finding anything using the search function.  What started out as a poor water pressure problem from BOTH pumps has quickly advanced to a complete wet bay rebuild!  I’ll circle back around to the pressure problems in another post after I get the floor replaced. 
Is there some kind of “approved fix”?  At this point my plan is to cut out a new floor from 14 or 16 gauge, weld it back in, paint and the maybe add a hardy backer type material, red guard , and tile it up to look nice and custom.  Any thoughts on this (aside from added weight?

[Richard]

It is not uncommon for bay floors to rust out.

I have replaced sections with 14G sheet metal. Be aware of underlying structure when cutting out with sawzall, grinder, or plasma.

I like POR 15 for the paint. Also check out a foam beak for using spray foam from the big box store to recoat the underside. https://foambeak.com/ A regular tip on the can will not spray upside down. I use a piece of 1/4 hose so I can hold the can upside down and the foam beak up against the horizontal surface.

[Gem930]

That foam beak looks like just the ticket. I was wondering how I was going to accomplish getting the foam in place. I already cut the floor out as you can see in the last picture using my hand plasma. I will use my CNC plasma to cut the replacement floor out , I’m just trying to figure out what the best way to finish the top will be. Thanks for the info.

[Latitude 28]

Gregg,
Here is a "Closed Cell" spray foam product that has more of a spray pattern for underside applications...https://krakenbond.net/collections/spray-foam-insulation.  Closed Cell would not absorb moisture.

[Jack Houpe]

I like Avantech flooring it's what used it our slide rebuild and also in the bay where the basement air unit were and a good choice for areas that could see water. Por 15 or Eastwoods rust blocker.
https://www.eastwood.com/eastwood-rust-e...oogle&wv=4

I like the way you jumped in and tackled the issue you will do well here keep us up to date.

[bestgenman]

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.

[Richard]

Building on Gordon’s theme, when I rebuilt the bay floors under the AC units, I added a fiberglass bathtub floor. I used fiberglass cloth and epoxy to make a protective cover for the steel floor. I spent some time in the composites industry and this is the same technique that would be used to waterproof a wooden strip canoe. If you go this way, a 3 wide paint roller handle, no roller, is a fantastic tool for spreading the resin and smoothing the cloth.

[folivier]

Can you tell the condition of the floor under the tanks?

[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.

[Gem930]

Can you tell the condition of the floor under the tanks?

It appears to be fine,  I have the fiberglass wedged up and have shop air blowing on it to dry it out.  Certainly surface rust in that area, but nowhere near the corrosion as under all the valves and filters that have likely vern leaking on and off for years.  There really was no good way to drain water out of there from leaks or even filter changes.