Bow water tank - Round two

My E38 has a 60 gallon stainless steel water tank in the bow, under the v-berth. I took it out in 2005 while checking for the source of fresh water pooling in the bow. I removed the tank, inspected it, cleaned it and filled it with water and it didn't leak. It went back in and has been in service since then. The past three years have been tough on the water system because we haven't used the boat since the fall of 2015 due to engine problems and other projects, not to mention the non-boating stuff you have to deal with.

In our limited use of the water system this spring I noticed some brown color sometimes in the water from the taps. So about a week ago I opened up the berth and took that first picture through the inspection port. Most of that sediment is probably rust and some of it sticks to a magnet. There is a very ugly spot on that weld on the left that makes me think there is some internal breakdown going on. The tank has been at least a third full also, for three years, just water sitting in there.

Second picture is to show that you can get it out of there. I had to straddle the opening in order to lift it out of the hole. I might add handles, or fittings on top where I can attach ropes, for lifting purposes. The tank is awkward, obviously, but not that heavy. It goes out of the companionway easily and doesn't threaten my dodger, which is a little lower than many of them out there.

The last picture is some telltale streaks from the welds. The 2005 inspection had identical streaks in a couple spots but they didn't leak. So I'm not sure what I'll find. I'm going to tap all the welds with a sharp instrument and clean the suspicious spots with a wire wheel. I am also thinking about adding two more inspection ports to the top so I can clean the outer areas that are blocked by the vertical baffles. I do want to look at that ugly weld and look for more along the side welds on the inside.

I am hoping to re-install the tank and use it provided it is not just worn out. At least for this season so I can plan a proper replacement over the winter. I'm also thinking about a piece of Dri-Deck under the tank to reduce the moisture trapped between the sloped bottom of the tank and the plywood floor.

Leak tests and access ports

The tank has been home for several days and I initially set it up on the ground, supported by a few sticks of wood. Half-filled with water, it leaked some, but not convincingly. I drained it and then used a brass wire wheel to clean up the welds and a few other spots that looked suspicious. I used a sanding wheel in a few places also, to take sharp edges of the welds down a little. Outboard of the baffles I cut the pair of 3" ports in the top with a Dremel cutting disc and then pressure washed the inside surfaces and especially the welds.

It is now set up on a pair of saw horses to provide better views of the drips. Filled with water to about 90% it literally rains water out of the bottom. Plus, each of the welds along the sides and front and back are seeping a little in places and there are a few pinhole leaks near the higher welds. The wire wheel treatment showed that there is some serious pitting on the bottom surface which is about 16 x 16 inches and sits on a piece plywood. Perfect trap for moisture. The pitted spots don't seem to be leaking, however. The steel is 18 gauge or 0.050" thick.

I have contacted a welder with stainless steel experience and I think the next step is to take it to him for an assessment, before I invest in any steel sheet.

Forward water tank

I had similar issues took it to a welder. It was a seam issue, took it to a welder a,d he wanted 300 to reeled but no guarantee. I have commissioned him to build a new tank $1200.00. Have now done all tanks on the boat over the last eight year.

Anybody get a quote for a custom plastic tank?

Should be a good use of polyethylene. Any reason why not?

Christian Williams said:

Anybody get a quote for a custom plastic tank?

Should be a good use of polyethylene. Any reason why not?

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How about Ronco Plastics?

http://ronco-plastics.com/

Pretty sure they did the holding tanks on our boats, at least some of them. And I know they can add fittings, adjust position etc. to whatever design you want.

Plastic tanks.

David, YOu're right, Ronco was the Ericson OEM supplier and are still alive and well. Glyn

fscott007 said:

I had similar issues took it to a welder. It was a seam issue, took it to a welder a,d he wanted 300 to reeled but no guarantee. I have commissioned him to build a new tank $1200.00. Have now done all tanks on the boat over the last eight year.

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Thanks for the info. How many gallons is your $1200 tank? I hope it is only $300 to $400 to repair this tank by welding a new bottom and cleaning up other welds and maybe patching some cracks or pinholes that are near welds. That assumes he lets me help without charging more for my participation. If I can get through a couple more seasons that would be worth it since there is a bit of a time crunch if we are going to get out for a month.

Emerald said:

How about Ronco Plastics?

http://ronco-plastics.com/

Pretty sure they did the holding tanks on our boats, at least some of them. And I know they can add fittings, adjust position etc. to whatever design you want.

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Thanks for the link to Ronco. I have visited their site in the past, but looking for holding tanks. I see their water tank business is bigger than ever. I have nothing against plastic for fresh water. I'm going to make some measurements and get an estimate and delivery date. Not holding my breath thinking I can get one in time for this summer.

footrope said:

Thanks for the link to Ronco.

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Welcome. Interested to see where this lands. So far I've been lucky, but I may have to replace mine at some point too.

Ronco tank making.

Craig,

I've had two tanks made for me by Ronco, one delivered to my home and the other I picked up at their plant here in SoCal. Once you have been clear with them as to just what you want and where you want the proper sized holes, they can bang a tank out in a matter of minutes, literally. Plates are attached to one another and then the hot, liquid polyethylene is poured into the spinning mold. I watched mine being made, a very slick process and timed it at 9 minutes. They allowed it a bit of time to cool and then took it elsewhere to spin the fittings in, another very cool process and thing to watch. If I had to guess, from the time Arrived until I had my new tank in the back of my wagon, I couldn't have been there more than an hour including time spent in the front office paying for the thing. In your case, getting it to Gig Harbor will be the most time consuming. Don't cancel summer plans on the boat just yet, order that tank tomorrow. in the case of having the one tank delivered to me, I faxed them an isometric drawing of just where I wanted the fittings, it was that simple. Take a look at a sliver of my holding tank made by them attached here. Go for it, Glyn Judson, E31 hull #55, Marina del Rey CA

Thanks for the encouragement, Glyn. That is a nice looking tank. I guess coming to an understanding about the shape and fittings/ports is probably the most time consuming, depending on how they cut the plates. I just got back inside after making the measurements and a set of four sketches. So, I'll be getting in touch with them tomorrow.

I'll post the cleaned up sketches and the results of my talks with Ronco in the next few days. I also have new batteries to install, etc. and the to-do list goes on from there in declining priority.

Amazing, Glyn.

In poring over Ronco's site I was reminded that water weighs 8.3 pounds per gallon. (Informed, actually, since I always thought it was 6 pounds).

I concluded, by the way, that the interior creaking on my boat to windward, which was very loud en route Hawaii last summer, is a direct result of the 40-gallon water tank that fills the starboard settee.

That water tank gives the boat its characteristic 3-degree list, when full.

When full, it also puts more than 320 pounds of weight up against the furniture/floorboards joinery, so that on starboard tck the boat driving to windward through seas squeals like a tortured cat.

It is good to know that the creaking disappears as the tank is emptied, and that any downwind course also relieves the pressure on the furniture.

For casual sailing, I now make sure the main water tank is less than half full.

Also:

"RONCO MARINE TANKS should always be stored out of direct sunlight and protected from freezing."

As to freezing--even an empty tank? That might be worth asking about for some climates.

another vote for Ronco

I haven't received my tanks yet but I've been working with Ronco this past week on the next system challenge on my boat...the head and plumbing. Rich at Ronco has been very helpful and has guided me to the right tanks that fit my space. No need for custom sizes. Long story short, I've taken the step to solo sailing since all the crew that said they'd love to sail with me have turned out to be mostly unavailable. When out for my first solo over night, I heard the auto bilge go off that caused a mild panic. But I couldn't see any water coming in from through hulls. So went back to sleep. Turned out that the holding tank was leaking. Gross.

Again, the boat project cascade effect has come into play. Figured out that the holding tank fitting was leaking and decided complete extraction was the best option; also planned on doing the hose connection correctly with a lockable y valve. Then figured I'd take out the fresh water tank since it stunk of sulfur (this boat had been seriously neglected by the PO). When soaking the water tank to clean it out, it cracked from the weight (I guess). So now I'm getting two new tanks.

My original plan was to take out the holding tank and put in a c-head. But the need to get a water tank made me conclude that two new tanks is cheaper, and that matters.

Any E27 owners able to share bow they have securced their tanks under the v-berth?

Anyway, long winded way to say Ronco has been great.
Jay

Christian Williams said:

water weighs 8.3 pounds per gallon.

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Indeed! "a pint is a pound" is a useful rule of thumb, but a pint of water actually weighs slightly more than 1.04 pounds, so... yeah, ~8.3 pounds per gallon.

Another sometimes useful rule of thumb is that a cubic foot of water weighs (approximately) 64 pounds. Which means a cubic foot of tank holds (approximately) 8 gallons...

Bruce

Another good material, albeit heavier, is SS.
When I had a custom fresh water tank fabricated the tare weight was about 70#, and it holds 38 gallons. This tank has a baffle and two clean out ports.
This replaced the Ronco rotomolded stock starboard settee tank that held 23 gallons.

When full this eradicates the common O-34 list to plot, i.e. the boat floats level.
Considering Christian's experience with weight changes I am glad that I reinforced that area with a couple of layers of roving before installing that tank. Nothing moves or gives.

Heavy water, indeed.
:nerd:

“In poring over Ronco's site I was reminded that water weighs 8.3 pounds per gallon. (Informed, actually, since I always thought it was 6 pounds).”

Christian,
You are probably remembering the weight of 100LL avgas for weight and balance calculations when flying piston aircraft. I, too, always need to remember that water is heavier than gasoline... hence it always settles beneath the fuel.
Mike Jacker

Exactly correct

No baffles in Ronco plastic tanks

Ok, I measured the water tank and attached a PDF for those of you who are interested. I called Ronco and talked briefly to the person who answered and asked a couple questions about submitting custom designs, got an answer to the baffles question (no) and also got Rich Gray's e-mail address. I sent him a PowerPoint with some notes and didn't mention baffles.

Has anybody got experience with (large) non-baffled tanks and would you share with us if it makes a difference in heeling or other handling, pounding into waves, breaking tanks or setting them adrift if they break loose? I don't think pitching would be a problem since the slosh would be in the short direction. Violent rolling might create a problem if it was the right frequency (rate) for the amount of water, but that's a calculation I can't do, even if I knew how much a gallon weighs. This tank sits with all its weight on the small bottom panel and has been held in place with two 1 x 3 sticks wedged over the top. No support on the sides at all.

Anyway, this Ericson 38 has the 60 in the bow. Later examples have much less (~40 gallons) so maybe there were some options, standard equipment changes or customization of the water capacity available when these were built. Or maybe someone said "that's too much weight in the bow" one day and everything changed.

View attachment Bow tank in one slide.pdf

"Plastics" might not be the best answer

I would spec out a 6" clean out port size, nothing less.
Move that vent to the centerline, behind the clean out.

Lots of angles in that tank; it would be ideal to build out of SS. Any shop that does "brewery grade" tank work could do it. And thanks to the boom in micro brewing there are lots more of these shops than there used to be. 50" is a long way across for a wave to travel --- I would want a center baffle. Matter of fact the tank builder can just put a 6" cleanup plate on either side of that baffle, like he did for our SS 38 gallon water tank.

I do not see how paying for a new steel mold for plastic rotomolding would pencil out at all, for what is likely to be a one-off. Ronco used to charge $600. to build a mold in steel, and that was many many years ago. IIRC the client then owned the mold.

Further, their process precludes baffles, as they explained.

PDF snipped: