Cleaning a Freash Water Tank on a 1977 Morgan 41

[Davieboy]

Hello everyone,
Can anyone help me with a piece of advise ... I'm about to buy a 1977 Morgan 41' and among the things on the "to do" list, I would need to clean the fresh water aluminum tank. Is it the same way you do it on an RV? Pour some bleach in there, then water, then flush out? Any helping advise is appreciated - thanks.

[Steadman Uhlich]

See this thread for the typical mix of opinions and tips.

Mould in water tank vent pipe - Cruisers & Sailing Forums

If buying an old boat, or any used boat, I would thoroughly clean the tanks and pipes and vent prior to drinking from an old tank. I have seen a lot of scum and bio growth and dead insects in water tanks.

Good luck!

[Cheechako]

Put some bleach in to shock it. You dont need much really, maybe 1/4-1/2 cup for 50-100 gallons. (dont drink a mix that high) Full tank so the top inside the tank gets doused also. Go motoring or sailing for a few hours letting it work and slosh around. Drain it , flush and drain again. Not sure bleach is too good for aluminum but like I said, you dont need a lot for it to kill things. and a couple hours wont hurt anything.

[Pete7]

If you have the time, how about opening an inspection hatch or if you don't have one then fit one. You might be shocked or pleasantly surprised. Either way at least you will know what's inside a 1977 tank.

Access Panels|tank|hatch|boat|water|TCL4

[Terra Nova]

Originally Posted by Pete7

If you have the time, how about opening an inspection hatch or if you don't have one then fit one. You might be shocked or pleasantly surprised. Either way at least you will know what's inside a 1977 tank.

Access Panels|tank|hatch|boat|water|TCL4

This. You need to physically scrub and mop out the tank, not just pour stuff in and hope.

[SuW]

Originally Posted by Pete7

If you have the time, how about opening an inspection hatch or if you don't have one then fit one. You might be shocked or pleasantly surprised. Either way at least you will know what's inside a 1977 tank.

I too agree with this. Unfortunately many production boats of this vintage don't have easily accessible tanks. I know someone who has basically abandoned a water tank because of this. The cabinetry is too nice and they have other issues to deal with...

[Terra Nova]

"It's too hard" is not an excuse.

[mcgann454]

Originally Posted by Davieboy

Hello everyone,
Can anyone help me with a piece of advise ... I'm about to buy a 1977 Morgan 41' and among the things on the "to do" list, I would need to clean the fresh water aluminum tank. Is it the same way you do it on an RV? Pour some bleach in there, then water, then flush out? Any helping advise is appreciated - thanks.

I can't remember where I got this, but I have done this every spring and my water has been tremendous. I do use a three stage house filter system to fill the tank as well as the recommissioning process.
My boat is in Michigan and sits on the hard for 6-7 months.
To sanitize the fresh water system and kill bacteria that may be present do the following:

• Fill the fresh water tank half way with fresh water.
• Prepare a chlorine solution:
  1. In a container with a gallon of fresh water mix 1/4 cup of household bleach, (5% sodium hypochlorite solution) such as Clorox or Purex, for every 15 gallons of tank capacity.
  2. Pour this mixture into the water tank.
  3. Complete filling of tank with fresh water.

CAUTION: Notify all persons aboard that the fresh water system is being sanitized. Do not allow anyone to drink from the fresh water system during the sanitizing process.

• Go for a drive to mix the solution.
• Turn on the fresh water pump.
• Pump water through each faucet so that the feed lines are filled with the water and bleach mixture from the tank.
• Run a quart of water out each faucet. You should be able to smell chlorine strongly at each faucet.
• The hot-water tank also holds water. Run the hot water faucets until the capacity of the hot water tank has passed through the system to insure that the old water has been purged from the hot-water tank, and it is now filled with the water and bleach solution from the water tank.
• Allow the water and bleach solution to stand in the system for three hours
• Drain the entire system, hot water tank included, and then flushes the system with new fresh water.
• To remove any excessive chlorine taste or odor that might remain, prepare a solution of one-quart vinegar to five gallons water.
• Pump the vinegar solution through the water system and allow this solution to remain overnight.
• Drain the system again and flush with fresh water.

[SuW]

...also, a 40-year old boat will probably need to have everything replacing...your purchase price should reflect that, if it hasn't already been done in the recent past...
Don't ask me how I know...

[Cheechako]

Originally Posted by Pete7

If you have the time, how about opening an inspection hatch or if you don't have one then fit one. You might be shocked or pleasantly surprised. Either way at least you will know what's inside a 1977 tank.

Access Panels|tank|hatch|boat|water|TCL4

[thomm225]

Originally Posted by SuW

I too agree with this. Unfortunately many production boats of this vintage don't have easily accessible tanks. I know someone who has basically abandoned a water tank because of this. The cabinetry is too nice and they have other issues to deal with...

My boat is a 1974 Bristol 27, and it's forward 22 gallon water tank does have the standard bronze screw on inspection hatch in the V Berth

It's about 6" in diameter

[SuW]

Originally Posted by thomm225

My boat is a 1974 Bristol 27, and it's 22 gallon water tank does have the standard screw on inspection hatch.

It's about 6" in diameter.

When we bought our boat it had a holding tank and fresh water tank under the V-berth. The holding tank had failed and the DPO* had used the adjacent, only, water tank as his new holding tank...
Fortunately we live in an area where we could wait until it was -15 Celcius before cutting them out...we now have a composting head, and a new water tank, with an inspection port...and we clean it out every winter.

The bonus is that instead of the original holding tank we now have a lovely, big chain locker in the bow.

My point is, with a boat of that age, it is likely that every piece of gear will need to be replaced or renovated, from portlights to seacocks. If something is built into the cabinetry, think about how you can get at it. It may look hard but it can probably be done.

*Damned previous owner...don't be one of these...

[thomm225]

Originally Posted by SuW

When we bought our boat it had a holding tank and fresh water tank under the V-berth. The holding tank had failed and the DPO* had used the adjacent, only, water tank as his new holding tank...
Fortunately we live in an area where we could wait until it was -15 Celcius before cutting them out...we now have a composting head, and a new water tank, with an inspection port...and we clean it out every winter.

The bonus is that instead of the original holding tank we now have a lovely, big chain locker in the bow.

My point is, with a boat of that age, it is likely that every piece of gear will need to be replaced or renovated, from portlights to seacocks. If something is built into the cabinetry, think about how you can get at it. It may look hard but it can probably be done.

*Damned previous owner...don't be one of these...

I see your point but some of us try and make our low priced Good Old Boats last as long as possible before we start replacing stuff.

So far, I've replaced the diesel (with a 5 hp outboard), mainsail, and cable lifelines (with polyester/dyneema line) I have also removed or capped off all the bad/worn hoses on the plastic Thetford Head (glorified porta potty) so it wouldn't smell anymore

I still haven't replaced the rigging, thruhulls/seacocks, portlights, the old electronics, or the wiring yet.

I'm still trying to see if this is the boat for me before replacing too much.

I bought it in 2011 and was sailing it a month or so after that.

It had been on the hard unattended for 5 years, and it's 44 years old

[SuW]

Originally Posted by thomm225

I see your point but some of us try and make our low priced Good Old Boats last as long as possible before we start replacing stuff...

I'm still trying to see if this is the boat for me before replacing too much.
I bought it in 2011 and was sailing it a month or so after that.
It had been on the hard unattended for 5 years, and it's 44 years old

Good for you! I definitely approve of keeping a Good Old Boat going (we even got the T-shirt "Will work for boat parts!") I see so many boats reduced to landfill by neglect, it's a crying shame.

Our boat had been flooded with meltwater and then frozen, so much of the interior needed removing and refinishing...mildew and water damage...including (thank goodness) the fine parquet flooring that some handy fellow had glued haphazardly to the cabin sole!

We removed and revarnished every single piece of interior teak...painted the bulkheads and inside the lockers and relaminated the horizontal surfaces. A lot of work, but not much expense and there's not much else to do up here in the winter

Also thank goodness, the engine was OK and the sails were good.

We've just finished making new upholstery and canvas, it's taken several years and the final piece (bimini) looks so much better than the first piece (dodger) that I might be obliged to do it again...you do build skills doing this stuff.

It's amazing how good she looks at the end of the process, it's been nearly 10 years...now, perhaps, we can get her in the water "early" for once!

Look us up if you're ever in the 1000 Islands!

[Dougtiff]

If the tank does not have a inspection port, one should be installed, you can purchase these, they are designed for retro fitting and come in different sizes. When i purchased my current boat, the faucet's did not output the proper volume, especially the hot side, upon opening the inspection port, i discovered about a 1/4 inch of silt on the bottom, this is on a boat that is only 10 year's old, talking to a plumber, i was told the city water has silt in it, after cleaning the tank's and replacing the hot water tank, i installed a water filter at the dock, what was happening, was the silt was clogging the small port's in the faucet, i would tear down the unit and clean and it would be O.K. for awhile, then clog up again, so a filter is a good idea.