So upon installing an access hole in my aluminum freshwater tank I discovered serious corrosion as you can see from the picture. The tank is glassed in under the v-berth so getting out would be hell. Can I cut a big hole in the top of the tank and put one of those plastic tanks right inside the old tank??
Corroded aluminum tank replacement
- Thread starter Stephentrapani
- Start date
Mine has the same thing and was leaking around the outlet spout. I took my anglegrinder/wire wheel cleaned it all out from the leaking area, wiped it down with acetone a couple times and filled in the seams with 5200. It has held for 2 + years now. I don't drink the water so no big deal.
When it ultimately fails I'm going to cut the top off the whole tank and install a bladder bag. I recommend the same.
When it ultimately fails I'm going to cut the top off the whole tank and install a bladder bag. I recommend the same.
Coatings and aluminum are difficult to get to work together. The problem is getting the surface of the aluminum clean so that the coating gets good adhesion. The second problem, specifically for potable water tanks, is finding a coating that does not leach out "bad stuff" into your drinking water.
If I had to do this, I think I'd look at liners rather than coatings.
dj
If I had to do this, I think I'd look at liners rather than coatings.
dj
Great solution! Both aluminum and plastic leach undesirables. Ours is p!astic. My project list contains an inline filter. Meantime we don't drink it either.
Not the first time for this problem to come up. Probably will not be the last...
My guess is that sometime in the late 70's the purchasing agent for Hunter was treated to multiple lobster lunches with copious liquor by the rep for an aggressive aluminum tank welding/fabricating company.
After good food and the 4th drink he forgot that aluminum was *totally* unsuitable for water or holding tanks and the price to supply ALL their tanks in this metal had become irresistible. (big sigh)
As noted by others, the metal is strong, but the problem becomes corrosion.
(in my youth I did grunt/labor work for a company that had several visiting manufacturers reps on a regular basis that were generous with their lunch accounts-- and had to be guarded against!)
Had your builder been a tad less driven by cost cutting, they would have refused to install aluminum tanks for anything other than diesel fuel.
OEM pricing being what it is, they could likely get a 'deal' any material that they chose, IMHO.
Water tanks= SS or plastic (rotomolded or welded). Holding tanks= rotomolded plastic.
They were not alone, either. Years ago when I replaced the original hot water tank in our boat (major brand) it discharged a small pile of aluminum oxide from a port when inverted on our dock after removal. Ick.
The replacement was/is all SS, and has remained taste and leak free for over 20 years.
BTW, removing a factory-installed tank can indeed be fricken tedious. But, once done and the replacement is properly installed it's 'good' forever. Jury-rigged solutions reduce the value of the boat and are a further hassle when you finally do decide to do it properly.
For drinking water you can use right out of the tap, easiest and thriftiest to source a new rotomolded plastic tank from Ronco. Great folks to work with, too.
My guess is that sometime in the late 70's the purchasing agent for Hunter was treated to multiple lobster lunches with copious liquor by the rep for an aggressive aluminum tank welding/fabricating company.
After good food and the 4th drink he forgot that aluminum was *totally* unsuitable for water or holding tanks and the price to supply ALL their tanks in this metal had become irresistible. (big sigh)
As noted by others, the metal is strong, but the problem becomes corrosion.
(in my youth I did grunt/labor work for a company that had several visiting manufacturers reps on a regular basis that were generous with their lunch accounts-- and had to be guarded against!)
Had your builder been a tad less driven by cost cutting, they would have refused to install aluminum tanks for anything other than diesel fuel.
OEM pricing being what it is, they could likely get a 'deal' any material that they chose, IMHO.
Water tanks= SS or plastic (rotomolded or welded). Holding tanks= rotomolded plastic.
They were not alone, either. Years ago when I replaced the original hot water tank in our boat (major brand) it discharged a small pile of aluminum oxide from a port when inverted on our dock after removal. Ick.
The replacement was/is all SS, and has remained taste and leak free for over 20 years.
BTW, removing a factory-installed tank can indeed be fricken tedious. But, once done and the replacement is properly installed it's 'good' forever. Jury-rigged solutions reduce the value of the boat and are a further hassle when you finally do decide to do it properly.
For drinking water you can use right out of the tap, easiest and thriftiest to source a new rotomolded plastic tank from Ronco. Great folks to work with, too.
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How much access do you have to the top? Nothing wrong-that I can think of-with putting a plastic tank inside the shell of your aluminum one. If you can't get a plastic tank in there, MikeHoncho's suggestion of a bladder bag sounds good.
Way too big for the opening. I can imagine cutting the tank up to get it out, including the extensive pain and torture that would involve, but how could you get a new plastic one in there? Is a liner the only realistic option?
Because it's under the berth cushion, I'd look at cutting the fiberglass top and lifting the tank out. There are many off-the-shelf plastic water tanks made to fit V-berth areas. One is likely to fit. Then glue/screw a wooden lip under the edge of the remaining fiberglass and drop the cutout piece on top. Fill the crack with putty and then paint. A great advantage of this route is that you CAN drink the water. I've banned bottled water on my boat - saves money, tastes as good or better as long as your run it through a filter, and helps the environment. Water / Waste Holding Tank - Ronco Plastics
