What's in your fresh water tank???? What's the best way to fix this?

[yachtman]

I am putting in a new teak wood floor in my Avanti 3450 and realized once I do that I can no longer work on the fresh water tank because it's under the cabin floor all sealed off.

I decided I needed to inspect it so I put a bore scope in it and this is what I found.


one of the areas looks like a possible leak. Pretty disgusting though. The black hose is the fresh water tank vent hose. It's supposed to be clear. You can also see the cork on the tank sender is pretty much rotten.

Any ideas on what's the best way to repair this? It's a 50 gallon tank. Aluminum. I guess I coukd have a new aluminum tank made. Probably cost about $700 to$1000.

I'm kind cleaning toward a bladder tank as there is one that will fit the space.

should I seal the floor back up or make it so I can access it.

[yachtman]

This is the sending unit and the floor where the tank is below. The measuring tape represents about where the tank ends.

the pic of the wood floor is maybe what I could do to create access to the tank. Maybe I'm over thinking it. Maybe I shoukd just replace the tank and seal it up.

a 55 gallon bladder I can get for about $120 a plastic tank in the $500 range and an aluminum probably around $700+

what do you think will be the best way to repair this?

[Sunbird]

I would go with a plastic tank. However remember that hoses, water level sending unit ,etc do not last forever. For those reasons I would do the extra work to make it accessible.
The example floor looks fantastic and has access.

[Jeffw]

I would go with a plastic tank. However remember that hoses, water level sending unit ,etc do not last forever. For those reasons I would do the extra work to make it accessible.
The example floor looks fantastic and has access.

Ditto.

[boatworkfl]

Plastic tanks, I will be building 2 fiberglass tanks to replace my tank on my 3870, there were more holes on the top of the tank than the bottom.
Aluminum water tanks are no longer allowed on new boats.

[yachtman]

Plastic tanks, I will be building 2 fiberglass tanks to replace my tank on my 3870, there were more holes on the top of the tank than the bottom.
Aluminum water tanks are no longer allowed on new boats.

My searay had a plastic tank and I used to drink the water from that system. My bayliners have all had aluminum tanks. No way do I drink that water. I bring lots of bottled water for that. After seeing the inside of this tank even less now would I drink from an aluminum tank.

[builderdude]

I vote cut out that discussing tank and replace with plastic or a bladder and definitely create an access hatch for future tinkering.

[yachtman]

I would like to replace it with a plastic tank however there aren't a lot of options size wise that will fit. I did find one that we 75 gallons a 25 gallon upgrade if i have length space. It seems to have a odd highth to width measurment. Too tall too wide or narrow and so on.

the bladder fits the space and is 5 gallons more. I'm going to try and cut it out later today and see what's going on.

[boatworkfl]

If buying a bladder be sure it has baffles.

[yachtman]

I guess it's later today already. . Here is the offending tank. 72×27×6 tag says 51 gallons I think I might even be able to go 3 inches deeper. I guess at least I'll have access to it now. Too bad it's all tabbed in. Probably impossible to get out without damaging it if that even matters at this point.

I'm actually glad I cut the floor out. The top of the tank was disguting full mouse crap and dog hair piles of dog hair..

[O1dSoldier]

I feel like there was a thread on here that mentioned a company that would make a plastic tank to whatever dimensions needed for what seemed like a decent price. I also recall a thread where someone replaced their aluminum tank with two smaller plastic ones and connected them at one of the lower corners. Too bad the pics didn't come through the site upgrade which seems like a customer support issue. But I digress.

[diveguy]

I have a 200 litre bladder and it works fine. You won't require a vent line but you can't connect a sender either. You'll need easy access to check the water level.

[diveguy]

If buying a bladder be sure it has baffles.

Once it has water in it, it doesn't move. The flexible bladder absorbs the motion of the water inside.

[yachtman]

I've thought about the no gauge thing on a bladder. This is what I've been thinking a in line water meter it can be reset when you fill so you know how much you have used providing you remember to reset at refill. It only costs about 25-30$

[diveguy]

I've thought about the no gauge thing on a bladder. This is what I've been thinking a in line water meter it can be reset when you fill so you know how much you have used providing you remember to reset at refill. It only costs about 25-30$

Perfect! I was looking for a solution to that problem. I ended up cutting an access hatch to check the water level.