• Mobile App For Android Now Online!

    Download it here. The app is searchable in the Google Play Store under Sailboat Owners.

    Sorry iPhone/iPad users, we are still waiting on Apple. :(

    Click the X in the upper right corner to make this go away

Aluminum Tanks

jviss

.
Feb 5, 2004
4,615
Tartan 3800 Westport, MA
As far as I know right now, all of the original tanks in the T3800 are aluminum. Mine's a 1996 model. Should I be concerned?

80 gallon fresh water;
25 gallon holding;
38 gallon fuel.

The good news is that the fuel and water are easy to inspect, and installed high and dry, under the starboard and port settees, respectively. I don't yet know the location of the holding tank.

There's also a big, trapezoidal, water tank under the v-berth. A fresh water, anchor wash-down was added last years, so maybe this is dedicated to that purpose? I'll find out.

Anyway, thoughts on aluminum tank lifespan, inspection, evaluation, etc, much appreciated.
 
Dec 14, 2011
316
Navicula 430 Hunter Toronto
if you start leaking on the holding tank and the water tank, you can cut a window in the top and use the west system to coat it and they will hold up good.....I did mine 6 years ago, and all is good
 

jviss

.
Feb 5, 2004
4,615
Tartan 3800 Westport, MA
Wow! Any idea as to what caused the corrosion? Is there any way to prevent it, like the way we put a zinc on the prop shaft?
 
May 20, 2016
2,989
Catalina 36 MK1 94 Everett, WA
Urine is hard on Aluminum. Very acidic. Zincs won't help and would you really want to go in there regularly to change them.

Les
 
Dec 2, 1997
8,073
- - LIttle Rock
The average life of an aluminum water tank is about 20 years due to the cumulative effect of carrying chlorinated water...shortened by adding bleach to each fill.

The OEM holding tanks on almost all boats were aluminum in the '80s when it first became necessary for builders to add them...but by the early 90s they'd begun switching to plastic because it had become obvious that metal is a bad choice for waste holding. Urine is so corrosive that an aluminum holding tank typically starts to leak at at weld--seam or fitting--within about 5 years and turns into a colander within about 10 years. An epoxy coating the inside can buy some extra time, but due to expansion and contraction as temperatures change with the seasons, coatings eventually peel and crack, allowing direct contact with the aluminum. The time to replace is when you see--or more likely start to smell--the first leak, 'cuz the first leak in a holding tank is always JUST the FIRST leak. You think that JB Weld patch on it has saved the tank, when in fact the bottom of the tank is developing pin holes that are getting bigger. The last thing you ever want is bottom of a tank that crumbles when you lift it out or discharge fitting that falls apart when you try to pump out--something that just happened to another poster to this site.

An average lifespan of 20 years makes aluminum ok for water holding, but no metal--not even 316 stainless--is recommended for waste holding...seamless thick walled (at least 3/8') rotomolded polyethylene is the recommended material.
Ronco Plastics Ronco Plastics marine Tanks (no relation to the VegoMatic Ronco) is your best source for a tank. They make TOP quality thick-walled water and waste tanks for a very reasonable price and has more than 400 shapes and sizes, over 100 of which are non-rectangular , and they install fittings in the sizes and locations specified by the customer when they make the tank.

Navicula, I hope you used food grade epoxy in your water tank. And after 6 years, I'd start keeping a very close eye--or nose--on your holding tank if I were you.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein
 

WayneH

.
Jan 22, 2008
856
Tartan 37 Pensacola Shipyard, FL
On my 1980 Tartan, the water tanks and the holding tank are plastic. The holding tank was replaced two years ago due to cracking of a spin-welded fitting.

The fuel tank is original to the boat with a 7-79 date stamped into its build plate. Still whole and holding.
 

jviss

.
Feb 5, 2004
4,615
Tartan 3800 Westport, MA
I've been scouring the web, found some stuff on magnesium anodes to protect aluminum water tanks.
 

jviss

.
Feb 5, 2004
4,615
Tartan 3800 Westport, MA
Urine is hard on Aluminum. Very acidic. Zincs won't help and would you really want to go in there regularly to change them.

Les
You would screw the anode holder in from the top of the tank. I've read a magnesium anode can protect an aluminum water tank, don't know about waste. Then, I'm not sure the boat's waste tank is aluminum yet.
 

jviss

.
Feb 5, 2004
4,615
Tartan 3800 Westport, MA
On my 1980 Tartan, the water tanks and the holding tank are plastic. The holding tank was replaced two years ago due to cracking of a spin-welded fitting.

The fuel tank is original to the boat with a 7-79 date stamped into its build plate. Still whole and holding.
Aluminum fuel tank?
 

WayneH

.
Jan 22, 2008
856
Tartan 37 Pensacola Shipyard, FL
Sorry. Yes, it's aluminum. And offhand, I can't remember the manufacturers name. Trident, maybe?
 
  • Like
Likes: jviss