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Wish I had done this! (ballast blowout)

Posted: Mon Jul 07, 2025 10:29 am
by LordElsinore
Yesterday morning I discovered that my beached :macm: was sitting with its rear end down in some mud. Could be the reservoir drained quite a bit in the less-than-24-hours it was anchored near the shore, or maybe I was too generous with my anchor scope.

Either way, it was a beast to push out. A couple strangers helped me push it when they saw my struggling with it alone (thank you!). I knew the ballast tank was full, but didn't think opening it would help since the valve was technically still underwater.

Found myself wishing I had done what OverEasy posted here:

https://macgregorsailors.com/mods/index ... em&id=2217

It's now on my list. A Mac with a full water ballast is heavy!

Re: Wish I had done this! (ballast blowout)

Posted: Mon Jul 07, 2025 12:17 pm
by Russ
I wonder how effective this is. Probably need to open the gate valve just a little so water is forced out.

Re: Wish I had done this! (ballast blowout)

Posted: Mon Jul 07, 2025 7:57 pm
by FittsFly
I like that set up. I would maybe want to add an air gauge to the set up (you can get a 0-15 lb gauge at most real plumbing supply houses) just to know what kind of pressure Im sending into the ballast. Could also verify tank isnt leaking when your back on dry land. Hopefully 2 or 3 lbs of pressure would be enough to push the water out.

Re: Wish I had done this! (ballast blowout)

Posted: Tue Jul 08, 2025 12:21 pm
by kurz
I use a 10.-- blower for summer gadgets in the water.
I can squeeze the pump directly into the whole from the vent whole.

Pumps out all the ballast water.

Re: Wish I had done this! (ballast blowout)

Posted: Thu Jul 10, 2025 5:55 pm
by OverEasy
Hi LordElsinore!

Thank you for the complement! :) :)
High praise indeed coming from a guy who has accomplished so much in this forum! :) :)
Glad you found it useful! :) :)

It works like a CHAMP at pretty much emptying the ballast when afloat on a level keel and the ballast gate valve cracked open a bit. Just a 1/4 inch gate opening seems to work nicely.
I found that standing by the stern to tilt the boat down at the stern while the air pump is running helps get the most water out of the ballast tank.
Once I see bubbles I gradually close the gate valve then go fwd to turn off/unplug the power. Disconnecting the hose equalizes any residual pressure that might have built up, but given the small displacement of the air pump there isn’t sufficient time between closing the gate valve and getting the pump turned off to be concerned about.

Eventually, if I use it regularly I’ll consider installing it permanently and routing a switch to the pedestal.
Meanwhile I made a 12 VDC extension cord that runs from the pump located under the foot of the V berth back to the cockpit pedestal where I already have installed two ‘cigarette’ plugs for the Chartplotters. That should be sufficient for our current needs for the time being
This is where I’m at anyway to open close the ballast tank gate valve anyway and monitor the progress.

While the gate valve is open the ballast tank only experiences the pressure of only a few inches of water column which is well within its normal designed use capability. If I were to make this a permanent fixture, rather than an as needed use capability, I’d be adding a simple weighted plug low pressure relief valve to preclude any potential concern of pressurizing the ballast tank. (I’d probably end up rigging it up to a set of electrical switches if I let myself get carried away… one rigged to the ballast gate valve so it has to be open for the air pump to turn on…and another to turn power off when the preset relief valve burps.)

It’s nice to be able to empty the water ballast statically while still in the water.
While I’ve only used for convenience I’ve not had to use it as a necessity (as yet :o :? :wink: )……..

As far as power draw we have a dual isolation battery set up so that we generally only run one battery at a time and either single battery is more than sufficient to start the engine alone. When we have used the air pump we have to statically empty the full ballast the battery in use was still sufficient to start a cold engine so it doesn’t draw much power to be an issue.

I’d not ever recommend trying to pressurize the ballast tank…it (the ballast tank) was never designed to be pressurized. The inflator pump we have works just fine at displacing the water from the tank. A pressure valve isn’t a bad idea but it would have to be a low pressure one calibrated one to be of use/interest.

Best Regards,
Over Easy 8) 8)

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Re: Wish I had done this! (ballast blowout)

Posted: Sat Jul 12, 2025 4:32 am
by FittsFly
I am looking at anchoring in a shallow water spot on a nearby lake and see your ability to pressure the water out of ballast intriguing . Question , has anyone ever measured their 26x ‘s depth difference between ballast being full vs empty? When I first got her I did try to compare the difference measuring from water line to the black lower stripe that our x’s have and didn’t see much difference with ballast full or empty.

Re: Wish I had done this! (ballast blowout)

Posted: Sat Jul 12, 2025 6:21 am
by Russ
FittsFly wrote: Sat Jul 12, 2025 4:32 am Question , has anyone ever measured their 26x ‘s depth difference between ballast being full vs empty?
I have a 26M and when ballast is full, the boat is about 2-3" lower, especially in the bow.

Re: Wish I had done this! (ballast blowout)

Posted: Sat Jul 12, 2025 9:26 pm
by OverEasy
Hi FittsFly

Ditto on Russ’ comment… about 3 inches or there about… maybe a bit more

I figure that being able to blow ballast is something in the right direction if/when aground. Enough to break free is all I figure is needed. If it’s stuck aground with ballast full then that’s 1500 lbs more stuck and the friction it will generate. Floating free by 3+ inches is frictionless….

The other aspect is if for some obscene reason Over Easy were ever to get a hull hole being able to gain an additional 1500 lbs of lift floatation could be of benefit…. :o :| :wink: :) :D

I like having options when the stinky stuff hits the fan… :D :D :D :D :D

Best Regards
Over Easy 8) 8)

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Re: Wish I had done this! (ballast blowout)

Posted: Sun Jul 13, 2025 9:20 am
by Be Free
FittsFly wrote: Sat Jul 12, 2025 4:32 am I am looking at anchoring in a shallow water spot on a nearby lake and see your ability to pressure the water out of ballast intriguing . Question , has anyone ever measured their 26x ‘s depth difference between ballast being full vs empty? When I first got her I did try to compare the difference measuring from water line to the black lower stripe that our x’s have and didn’t see much difference with ballast full or empty.
The official number is 643.48 pounds per inch of immersion. 1400 pounds of ballast should lower the boat a bit over 2 inches.