Custom Watertank

Marshall Wright · Post by **Marshall Wright** » Mon Jan 28, 2008 5:09 pm

Greetings,

BTW, I've searched and all I found were discussions about fuel tanks.

Has anyone ordered or have any useful advice re ordering a custom watertank? I've decided that poly is what I need. Any good leads on a company that will make me up what I need? Unfortunately, a stock tank won't work. I've got to lower my tank to allow room for some x-stringers to resupport my sole that I tore out. Want to take advantage of every cu. in I have left!

Thanks in advance,
Marshall

Capn_Tom · Post by **Capn_Tom** » Mon Jan 28, 2008 5:47 pm

Maybe not custom but these folks do offer a bit of variety http://www.ronco-plastics.net/

bcooke · Post by **bcooke** » Mon Jan 28, 2008 11:20 pm

For a custom, one of a kind water tank you might want to consider stainless steel. Most any welding shop can make one for you.

It won't be cheap. But then neither will a custom poly tank either.

-Britton

Post by **Tim** » Tue Jan 29, 2008 7:05 am

This particular business probably isn't convenient to you, but represents one of the many custom plastic fabricators that exist out there. You might check in your area for a similar company.

http://www.sullivanplastic.com/

Hirilondë · Post by **Hirilondë** » Tue Jan 29, 2008 7:51 am

For custom water and holding tanks we use a company that fabricates poly tanks much like the one Tim links. They are definitely cheaper than stainless and in my opinion better. Many people argue that plastic tanks add a flavor to water. I have found this to be minimal. Factor in that most boatyard water is city water that doesn't taste very good to begin with. If you want delicious water you will have to filter it or carry bottled anyway.

Ceasar Choppy · Post by **Ceasar Choppy** » Tue Jan 29, 2008 3:48 pm

I have found these folks to be great with custom plastic tanks.

http://www.triplemplastics.com

The important difference between polypropylene tanks that can be welded and the polyethylene tanks that are rotomolded is that the welded tanks allow for baffles.

bcooke · Post by **bcooke** » Tue Jan 29, 2008 6:21 pm

Definitely consider baffles...

Marshall Wright · Post by **Marshall Wright** » Sat Feb 02, 2008 12:08 pm

Thanks for the advice.

I've received a quote of $500, less shipping, from a very reputable RI firm in "marine-grade" aluminum that meets all CG safety standards. Includes baffles, in/out/vent/monitor connections.

I'm waiting for TripleM and another company to get back to me in poly.

Questions. Does aluminum impart any taste to water? I'm assuming that the poly tank will be somewhat less and probably has the same lifespan? Why would I go for the aluminum? Any other advantages?

Marshall

Hirilondë · Post by **Hirilondë** » Sat Feb 02, 2008 8:28 pm

Marshall Wright wrote:I'm assuming that the poly tank will be somewhat less and probably has the same lifespan?

I would bet poly has a greater lifespan, but as both should last quite a long time I don't know that it should be a big consideration. The Coast Guard has a standard for water tanks? I know that for fuel, aluminum is all they approve (consider they are dealing with commercial and for hire boats).

feetup · Post by **feetup** » Wed Feb 13, 2008 11:30 am

The heat-extrusion welds used to assemble HDPE are not as strong as the material itself, but this is a problem with aluminum as well. For a welded Poly tank it is important to spend effort on a well supported installation, since poly will settle and deform under any load in time. They are after all made of plastic, and the definition of "plastic is the ability to yield to strain over time. Hang a heavy coat on a plastic coat hanger and wait a few months. Aluminum on the other hand is very stiff, and if the mountings flex, the tank may crack in time. It is frightening how much dynamic loading can be applied to the walls of a container holding a liquid in a good sea. Baffles help this a lot but consideration should be given to both pitching and rolling. The taste of the water won't be of much importance if it is all in the bilge because a seam split.
If it comes to a choice between electrically inert HDPE and Aluminum, which sits almost on the bottom of the metals nobility scale don't let anything but dissimilar metals and common sense hold you back.
That being said, I was involved in the development of some ore haulers for a mine in the arctic that had welded HDPE liners. We had a lot of failures in testing but the end product held up very well.

I think that a tank in a peasure boat is one of the GOOD things we can do with oil, way better than burning it.

Feetup

bcooke · Post by **bcooke** » Wed Feb 13, 2008 11:43 am

With aluminum you are going to get a small amount of aluminum oxide in your water. I really have no idea what the safe amounts are.

My stainless steel 28 gallon custom made, no-square-side-anywhere water tank, with all the fittings cost me about $500. If I were to chose between aluminumn and stainless I would go stainless. If I were to choose between metal and plastic... that is a whole other story. I never did enough research to offer any advice on that.

As for taste; I have to wonder if the tank is adding taste to the water how healthy can it be? Probably fine but I really don't know. Clearly, dockside water doesn't taste good to begin with but it is what is added by the tank that had me wondering. I too will definitely be adding a robust filtration system to my fresh water system. I have seen dockside drinking water come in many different colors.

-Britton

Tony · Post by **Tony** » Fri Feb 15, 2008 2:19 pm

I have seen dockside drinking water come in many different colors.

Oh, come now, Britton, thats just a feature. :-)