Water tank issues

Solly said:

Looking at your pics again it seems you have support to the front, back, bottom and 1 side. If you could fab support on the 1 side ( inside ) left you could go with a flexible tank.
Maybe reconsider that now that you have the access and open space...

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I’ve got support on all sides. The only thing I’ve cut out is the top of original tank.The new tank will be around 40 gallons , 10 gallons less than original. I had to build it smaller because of the hatch I had to through and also a deck support I had to work around. The new mock up nest in the hull almost perfect.
I don’t know what it is about a bladder but I’ve never liked the idea. I’m sure they’re fine.

1/8 sounds much better than 16 gauge. 16g can be welded, but how will those welds hold up over time...

Regarding SS or other tank fabrication/installation, see this link I had found a few months ago, its written by a TF member you probably know, the sections in green deal with tank installations...

http://stevedmarineconsulting.com/wp-content/uploads/2014/03/WaterSystemsPt2-153-03.pdf

David

fractalphreak said:

1/8 sounds much better than 16 gauge. 16g can be welded, but how will those welds hold up over time...

Regarding SS or other tank fabrication/installation, see this link I had found a few months ago, its written by a TF member you probably know, the sections in green deal with tank installations...

http://stevedmarineconsulting.com/wp-content/uploads/2014/03/WatzzzerSystemsPt2-153-03.pdf

David

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Thanks for the link David , I’ve read about using 316L instead of 304.My davits were built from 304 about five years ago and so far no rust is showing up at the welds . I’m in fresh water so it will probably take longer for them to rust. But for the tank it looks like 316L is the way to go and 1/8” thick.

I’m afraid I’m going to wind up cutting the deck to drop in the tank because of weight, now it’s starting to get over my expertise. If I did cut the deck open I could build the tank to original size and just drop in then, but that means I would probably have the get the yard involved $$$$. I may be looking to a plastic tank fabricator. At least now with the latest mock up I have the size,shape and fit to the hull right. Sooner or later I’ve got to make up my mind and go for it.

Here is a picture of my davits that the welder I’m going to use for the tank made. I made him kind of a mock up for these first.

"Sooner or later I’ve got to make up my mind and go for it."

Go for the plastic already made tanks.

Safer than SS long term ,far cheaper, way less hassle and the slightly reduced volume might only be a hassle on rare occasions.


KISS

Custom well made pot water tanks available from Miller Plastics Burkettsville pa. 10 yr warranty. I reolaced both my old ss tanks made H less to get in door. Very nice. Great company to work will. See website.

I'm not sure why you would have such a problem with bladder tanks. Seems in this instance, with the full support of the original tank sides, a custom or even off-the-shelf bladder as previously linked dropped inside of the existing tank carcass would be easy-peasy.

In airplanes, we would retrofit "wet" wing tanks that eventually leaked (wet wing is using the actual wing skins as the tank) with bladder tanks instead of dealing with the nightmare of chasing wing tank leaks.

The ATL custom would be a no brainer. Probably wouldn't even need to worry about the stringer in the middle as they could probably custom that in.

http://www.atlinc.com/potable-drinking-water-bladder-tanks.html

Also... why not make mock-ups in heavy cardboard instead of luan ply...

Good luck!!

Thanks guys , all good suggestions. I’ve found a plastic tank that will work. I’ve just been dragging my feet a little.
Fly bull I use plywood because I’m a woodworker and it’s easier for me to work with and it will stay stiff like a hard plastic tank when I’m cramming it through the tight areas. I was afraid cardboard would bend and change shape when forced through tight areas.

Pack Mule said:

Thanks guys , all good suggestions. I’ve found a plastic tank that will work. I’ve just been dragging my feet a little.
Fly bull I use plywood because I’m a woodworker and it’s easier for me to work with and it will stay stiff like a hard plastic tank when I’m cramming it through the tight areas. I was afraid cardboard would bend and change shape when forced through tight areas.

Click to expand...

Roger that.

Hope all goes well with the new tank !!

As far as durability of a SS water tank, I have a 70 gallon tank of SS. A prior owner replaced the original 1970 monel tank decades ago. I am sure the tank is 25 or more yrs old. It is a continuous machine welded construction.
It is bent into a rectangle and the ends are welded on.
Fill and vent is on top edge, and outflow on bottom side. It is not .125" thick. I would guess it is .060 to .080" thick sheet metal. And the tank is perfect. It sits on wood stringers, not plywood and is open on the bottom exposed to the bilge. So it does not stay wet on the outside, only on the inside. It is boxed in with 3/4 plywood bulkheads. If I had to remove it, the gen would need to be lifted out of the aft lazarette. I did remove the one plywood side to inspect it yrs ago.

New tank came in today from Ronco. They were great to deal with. This tank should nest almost perfect to hull. If this works like I want it to on the port side , I’m planning on ordering another for the starboard side. This tank is only 20 gallons but it will get us by for now.

They do indeed make a nice tank.

Water tank is done. Not a project that I’m that proud of but it will get us through.

Excellent! I bet you are glad to see the end of that one.

Looking at the photo I see what looks like an old style accumulator.

These do work , but usually do not have a diaphragm , so the air gets absorbed by the water.

No big deal but you must drain the unit every month or so to allow air into the unit.

A larger unit that can be pressurized might extend the pump and switch life.