Changing Ballast Water

[Steve A.]

I was reading in the archives where Ken posted something about changing the water in the H260 ballast tanks while in the water. There were numerous replies about adding fresh water through the vent hose, adding Clorox, and using a pump to empty. Has anybody tried using a compressor to slowly add air through the vent hose with the bottom valve open?

 

[Rick Macdonald]

That was also suggested but rejected

I think Crazy Dave went crazy at that suggestion. The concensus was don't do it - the ballast tank was not designed to be under pressure....RickM...

 

[Ron M]

Hotly debated

The idea of using compressed air to blow out your ballast has been hotly debated here. Some feel that it can overstress the ballast tank and cause a failure. Sounds reasonable, because even a few psi over a large area equals a lot of force. On the other hand, some argue that since the ballast tank valve is open, pressure is limitted because it can't build up.I imagine this can all be calculated if you know the difference between how deep the boat sits ballasted vs. empty. For example, if the boat settles 6" when full, it would take a 6" head of water pressure to push the water out. To convert from inches of water to PSI you multiply by .03613 :6in of water x .03613 = .217psiMy method may be flawed, so please feel free to jump in with a correction. I'll leave it up to the individual to decide if that pressure is a problem or not.Ron Mehringerh26 Hydro-Therapy

 

[Rick Webb]

There is someone Who is Doing Just That

I am not sure it is on a Hunter. So long as the valve is open and you are not using some sort of high pressure, high volume pump I do not see where the inherent risk is. Anyone who thinks the tank will not stand and increased pressure in the ballast tank just needs to pull the vent plug one summer afternoon. The whoosh you feel and hear is more than just one or two pounds per square inch. My thought was to use a small shop vac they put out a larger volume at a smaller pressure than does a compressor.

 

[LKYusnret]

As a retired Sub sailor

with a H260, I had thought about it and asked Crazy Dave he said that it wasn't a good idea. That's good enough for me, I won't do it. Baums Rush

 

[Mark]

Why empty it?

Just change the water if you really feel there is a need.I figure that to freshen the water in your ballast tank all you would need to do is:1) Undo the thumb screw so that the drain plate is hanging beneath her.2)Take out the inspection plug-cork.3)Get a garden hose and shove it in the inspection hole and turn on the water.4)In no time at all the water within the tank will either be, watered down and refreshed or to a fair degree replaced.For the old water will slowly exit or mix with the new water.How about that for an idea from downunder??Oh by the way just make sure you hang around while you do it for a water hose could fill a 260 in no time if it came out of the vent hole!!

 

[Tex22678]

Second to Mark's Idea

I have done the same as Mark. Open the valve and turn a water hose on medium to low. Drink a beer and hang around for a little while. Shut off the hose and shut the valve. Presto.

 

[Mark]

Hey Thanks Tex

I like the idea of a beer.In fact I might just mosey on down there right bloody now and crack a tinnie and refresh my water.

 

[ROADBOAT]

PRESSURE'

I WONDER JUST HOW HIGH YHE PRESSURE GETS TO DO THAT, I WOULD DO BLEACH IF IT DOESN'T HURT FIBERGLASS.I HEAR ON THIS SITE AT TIMES ABOUT PEOPLE LOOKING FOR LEAK ALLREADY.

 

[Mark]

You do not need and do not want lots

of pressure.Simply filling the tank with fresh water from above will dilute and to some extent replace the water that is in the tank.

 

[Tom2909]

Have blown water out....

When I had my Mac26 (1990 SAILBOAT), on a couple of occasions the water level in the lake had dropped and I had to unload ballast to float higher on the water get to the ramp.In order to do so, I used a low pressure, high volume foot pump (used to blow up air beds, inflatable boat, etc.) to blow air into the vent at the top of the ballast tank WITH THE BALLAST VALVE OPEN. This worked just fine (and I got a lot of exercise). I now keep one on the boat when launching/hauling, just in case. I haven't used in on the H260 (1999 model).Seveylor does make a 12 volt HIGH VOLUME, LOW PRESSURE pump that could be used, too. BUT I would be very careful. With the foot pump you provide the air in small puffs followed by delay while the pump is refilling on the upstroke. An electric pump provides a constant stream of air. I imagine that if you hold the pump output nozzle to the vent hole and remove it every few seconds, you will do just fine.The ballast tank is under pressure when filled. the pressure of the water trying to fill the tank is evident by the fairly forceful stream of air exiting the vent hole. The ballast tank certainly stands up to that OK, and should be able to take a little extra force to reverse the flow of water in.The air pressure of a filling ballast tank is calculated at 2/33 * 14.7 = .9 PSI.2 ft is depth of ballast fill hole33 ft is depth at one atmosphere1 atmosphere = 14.7 PSISo just 1.5 to 2 PSI should be enough to reverse, but you are also increasing the force on the ballast tank by 1.5 to 2 times, too.To put in perspective, an inflatable is rated for 3 PSI (about the output of a foot pump), the high pressure inflatable boat floors inflate to 11 PSI.Fair winds,Tom

 

[Tom2909]

Another perspective

Are you having ballast water problems?I've had a water ballast boat since 1990 in both fresh and salt water. Some years I have put chlorine in (about 1 or 2 quarts), other years I have forgot. My boat is in the water for 5 months (Live in New England), and I have never had a problem with foul water at the end of the season. It could be different for warmer water climates, longer periods in the water and the stuff that comes in with ballast water from your local waters.I have read that chlorine will pit stainless hardware, but have not noticed that it affected the ballast valve stem, so maybe the concentration is low enough. I don't think it is an environmental hazard to let chlorinated water back into the lake or sea at these minute levels, either.Fair winds,Tom

 

[Ron M]

Options

If all you want to do is keep the ballast tank odor free, then a little bleach is your easiest, and probably safest, route. Why bother with all the pumping when funneling in a little chemical is a proven method.However I can envision situations where you might need to blow out the ballast, like when the lake has dropped too much at the end of the season and you can't get the boat on the trailer. I used to keep my boat in a shallow part of the bay and would sometimes get hung up when backing away from the dock. Could have used a little ballast relief in those situations.IMHO, blowing out the ballast with a low pressure air source is a viable option. In the other thread on the subject someone mentioned that this is common practice among Catalina 250 owners. Time for me to do a little more research...Fair winds,Ron Mehringerh26 Hydro-Therapy

 

[CORKY16789]

BROWNIAN MOVEMENT

1. If you open the bottom by brownian movement, the spontaneous movement of molecules the water will be exchanged. If you are moving through the wter will happen faster. I just pour a little chlorine that is used in a hot tub into the tank and do not chang it all year in a Kansas lake. It never smells. I do the same for my fresh water holding tank.2. to remove wter at the end of the year I got a pump from a supply store and pump it out from above. I think pumping air in with enough psi to move water out the bottom is too risky. Why work against water pressure?ct

 

[Brigg]

Air Pressure vs Water Pressure

I don't have a problem with changing ballast water since I store my H260, "Wand'rin Star" on it's trailer, but I do have a problem with shallow launch ramps. I hate driving my 4Runner into the lake up to the tail pipe to retrieve the boat onto the trailer. (Yes I use the trailer tongue extension.) So think about this:If you launch your boat with an empty ballast tank and the bottom fill plug is open, so water and it's associated pressure can enter, without opening the top vent plug, you have the maximum pressure in the tank needed to keep or get the water out. The tank has to be built strong enough to hold that amount of pressure or we would be blowing holes in it everytime we fill the tank. If you can calculate what pressure is generated in the emply tank to hold the water out and increase that pressure by one pound, you will push out any water inside. You could get one of those guages used to measure engine cylinder pressure through the spark plug hole and fit it into the tank vent hole. Then if your compressor can be set for a maximum pressure of one PSI above the pressure mentioned above, you will not run any risk of blowout.Myself, I prefer just using an extra bilge pump I keep on hand as a spare. I also use it to pump out any water that gets under the floor in the cabin. Since it has an intake hose and output hose I pump the water out of the top of the ballast tank vent and into the sink. the boat floats higher and goes on the trailer much easier.Brigg

 

[bob fliegel]

Bilge Pump - The Way To Go!

I also, like Brig, use a small Rule 500 gallon per hour bilge pump. It empties the tank in about 30 minutes and works great. It cost about $19 and works off the 12 volt battery.I probably got a little carried away with the installation. I installed a deck access plate under the cabin step and mounted a clip on the bottom of the water tank to hold the pump in place.I left pictures on the photo forum.Everyone keeps talking about using preasure to empty the ballast tank but I can't see how anything can be any easier than a simple bilge pump.