Installing New Holding Tank in GB 42

I have a leaking holding tank in my 30 yr old GB 42 and got great guidance from this forum on a replacement tank from Ronco plastics. For anyone who has done this project before, one question: the old steel tank is tightly fit in an opening between the engines that's just under 16" wide. the new plastic tank is only 13" wide so I'll need to use a material to support the tank's sides and fill the gap, approx 1 1/2" on ea side. First thought was using wood. Also thought of a foam fill. For anyone who has done this before, please advise.

I would use Starboard or PVC board.

No painting, no rotting.

Second on Starboard. Foam might crush the tank when expanding if there is no way for the excess to get out. If you do foam, go a little at a time.

Holding tank install question

thanks for material suggestions!

I used the Man-Made decking from Lowes. They have it in 2x4, for hand rails, and I just ripped it to the appropriate thickness and taper and use it in strips to both support the tank and lock it in place.

Marty....................

MartySchwartz said:

I used the Man-Made decking from Lowes. They have it in 2x4, for hand rails, and I just ripped it to the appropriate thickness and taper and use it in strips to both support the tank and lock it in place.

Marty....................

Click to expand...

That's another good idea.

Holding Tank Install

thanks for the man made decking suggestion. considering the thicknesses I need, makes more sense.

Spray in Foam, , If ever needed it can be removed by hand .