Adding a larger grey tank to a 78 Tradewind

[johnhh]

I have a 1978 25 ft. TradeWind with the infamously small grey tank (like 12 gal. - rediculous!). I have recently dropped the belly pans because I had a split brake line that needed repair,,, and now I have removed the side wraps so I can wire brush and POR15 the frame as long as I am there..... And, since I am there, how about installing a bigger grey tank????? Madness.... just madness....

So, what's the easiest approach to adding more grey tank capacity?

I can add a second tank closer to the axles, but there are some drain pipe height issues to work out and, the existing grey tank will have to be replaced since I can't cut into it and I can't merge into it's discharge line.

Oh yeah, I also want to install a macerator semi-permanently.... there is just enough room for it, I think....

Does anyone out there have the drain pipe plumbing diagram from the service manual for a mid-to-late 80's, or 90's, 25 ft. TradeWind with the rear Shower Bath configuration? I am looking for ideas....

And, do I really need the foam pad under the tank? I am not winter camping (not using water when I do) and I will support the tanks independent of the bottom cover.

Thanks.

John H

[Aage]

Wow, you have a 12 gallon grey tank? That's luxury to me; ours is ten gallons!

It's my belief that you will need top access to change the tanks fabout, or just add a second grey tank because of the way the tanks are suspended on the frame rails. By that I mean remove lots of interior (oh NOO!)

But check with an expert: Member Colin H will know...

[johnhh]

I was being generous at 12 gal., you are probably right at 10 gallon. It's a damn small tank...

Top access is not what I want to hear. but no, no, no. The bottom is off, I don't want to be tearing out the inside...

John H

[heslinhotel]

John H,
I think you want to keep the foam pad. It will keep tank from shifting and chaffing, which will eventually lead to tank failure.