37 year old poop tank- Oh boy

[Marco Flamingo]

Why is that the only location for it?

Not the only, just the best. Forward of that is the front bilge area where the present tank is. The area is long, skinny and dark with the forward end up a few inches, so I lose a gallon or two in capacity because of a slant. Moving it under the engine room floor, I could sit it down lower in the bilge and double the capacity. As I noted, then I can repair the bulkhead (and soundproofing) that was mangled when the PO decided to stick a skinny tank forward under the V berth floor.

Just thought of another benefit for that location. I can easily look at it and see how full it is. I know that they make fancy sensor-gauge-light-alarms for this purpose. Probably with Bluetooth WiFi connections that call my cell phone with hourly updates on how full, what percentage of #2, etc. I'd be happy with just being able to easily look at the fill line.

It is a small boat. The picture to the left is almost life size.

 

[Flatswing]

Since you were able to get the tank out, replace it with a good quality poly. Metal holding tanks are a leak waiting to happen - again and again...

 

[ScottC]

Seven years ago, I decided that I'd had enough of trying to live with a single, 17 gal. black water tank (which is what came standard on my boat). I wanted to at least double that capacity. My choice was to strap in a 15 gal off-the-shelf plastic tank in the bilge and totally destroy access to everything and eliminate any possibility of storage in the vicinity...or to go custom. I ended up going the custom route, which cost me about double what off-the-shelf would have cost. I added 20 gal. capacity, preserved access to everything and, actually, enhanced usable storage space to a certain extent.

If you can find a way to afford it, I would recommend going the custom plastic tank route. While it's not nearly as cheap as using off-the-shelf tanks, the "payback" in my experience is many years of: 1) enjoying the extra capacity enabled by custom, 2) avoiding the potential waste of valuable storage space that can be experienced when choosing off-the-shelf shapes/sizes over custom, 3) enjoying years of patting yourself on the back for investing in the optimal solution vs. a "make-do" solution.

 

[Osprey69]

I will send you a PM. I just did this job on my boat. A few tips will make your life much easier.

 

[Marco Flamingo]

I found my holding tank file. Here are a couple of off-the-shelf tanks that I thought would fit my Tung Hwa 30. 31 gallon ($375 plus shipping) and a 50 gallon ($470 plus shipping). Both would fit between the stringers and below the engine room floor boards on my Tung Hwa, although the 50 gallon is so long that it would have to extend forward out of the engine room. Fixing my forward ER bulkhead and restoring the soundproofing is part of the project, so I'd likely go with the smaller tank and just double my present capacity. Maybe more than double. Who knows what might be cemented in the bottom of my 40 year old tank.

I haven't checked locally to see if a tank dealer in Seattle might have something in stock. I also haven't looked to see what shipping adds to the tank price.

 

[rslifkin]

I found my holding tank file. Here are a couple of off-the-shelf tanks that I thought would fit my Tung Hwa 30. 31 gallon ($375 plus shipping) and a 50 gallon ($470 plus shipping). Both would fit between the stringers and below the engine room floor boards on my Tung Hwa, although the 50 gallon is so long that it would have to extend forward out of the engine room. Fixing my forward ER bulkhead and restoring the soundproofing is part of the project, so I'd likely go with the smaller tank and just double my present capacity. Maybe more than double. Who knows what might be cemented in the bottom of my 40 year old tank.

I haven't checked locally to see if a tank dealer in Seattle might have something in stock. I also haven't looked to see what shipping adds to the tank price.

Both of those are good tanks. When I re-did mine, I bought a 70 gallon from Trionic. Although I bought a blank tank and installed my own fittings, as I wanted a dip tube for pumpout and all fittings on top.

 

[OldDan1943]

If you are replacing your tank, how do you dispose of the used tank?

 

[rslifkin]

If you are replacing your tank, how do you dispose of the used tank?

If it's metal you could clean it out and scrap what's left. When I replaced my old one, I flushed it out before removal and then capped off the ports and tossed it in the marina dumpster.

 

[HeadMistress]

Here are a couple of off-the-shelf tanks that I thought would fit my Tung Hwa 30...

Most off-the-shelf tank walls are only 1/4"...the prices you quoted are a good indication that's what those tanks have. That's not thick enough to support the 8.333 lbs/gallon water and waste weigh so the walls would have to be supported on all sides to prevent bulging and flexing that inevitably results in a cracked tank. Most likely you'd also have to accept pre-installed fittings in "standard" sizes (1.5" inlet and discharge, 5/8" vent) and locations (all at one end) or pay a hefty upcharge for "custom" fittings.

I've recommended Ronco Plastics tanks because their wall thickness start at 3/8" and the first three fittings in the sizes and locations specified by the customer when they make the tank are included in the price. Discharge fitting on the top of the tank with a diptube adds a very reasonable amount to the total cost as do any additional fittings. And finally, they sell direct for a lot less than you'll find their tanks or any comparable tanks at any retailer. With 400+ shapes and sizes in their catalog, you're almost guaranteed to find one that'll fit your space. And they're great to work with! Btw...they're in Tustin California...shipping to Seattle would be very reasonable.

I have NO "axe to grind" by recommending Ronco, btw. My opinions are my own based on my own experience (I was a distributor for 10 years) that of boat owners over the years.

--Peggie

 

[rslifkin]

At least in the larger sizes, Trionic uses 3/8 wall. That's what my tank measured at when I drilled for fittings.

Personally, between the 2 brands, I'd use whichever has a better size available. Some resellers will let you order a Ronco tank with custom fittings. I've only seen that available in larger quantities for Trionic tanks. So that may also be a deciding factor.