So, how much does a dink full of water weigh?

Well, that’s it.  Yesterday evening Pandora was hauled for the winter.  It’s over and we won’t be sailing again until next Summer.  It’s the first winter in her decade of service that she has been on the hard for winter and I am not happy about it.

With boats it always seems that “it’s always something” and the last week or so hasn’t disappointed.  In the aftermath of the huge hurricane, Florence, that slammed into the Carolinas, the much weakened storm headed up through our area and dumped a remarkable amount of rain as it passed through CT.

As is my custom, I had left our dink up in the davits on Pandora but on this occasion I neglected to pull the drain plug.  That turned out to be very bad oversight as the nearly 7″ of rain that fell overnight filled the dink, which, as you recall, was hung up in the davits, nearly to the point of overflowing.  Between the rain that landed directly into the dink, along with the rain that ran off from the big solar panel above it, there was hundreds of pounds of water sloshing around when I returned to Pandora the next morning.

The dink and motor alone weigh in at around 175lbs and add to that perhaps another 500lbs of water at 8.3lbs per gallon, and you can see how quickly the weight added up.   Our davits are pretty strong but that massive weight proved to be too much for them to bear and the starboard leg of the davits, the outboard motor side, bent down 3-4″.   Oh boy, was I sad when I saw that.

I knew from past inquiries, that there isn’t a mobile stainless guy anywhere so this repair was going to have to me done by MOI.  I thought about this for several days and finally settled on a plan.

A few years ago I had hired a yard in Ft Pierce FL to straighten the bow pulpit and having watched that process, I realized that it was going to take a tremendous amount of pressure to bend two 1.5″ stainless tubes several inches.

The bow pulpit process took a remarkable amount of pressure too and it was only 1″ tube.  I wrote about the process in this post.  So, back to my sagging davit.  I knew that it was going to take a lot of pressure, hundreds of pounds at least, to push the sagging stainless, 1 1/2″ tubing and a brace of the same diameter back into place.  And to get it to settle at a level point again would mean that I’d have to push it up way beyond level so that it would end up where it belonged when I released the pressure.

In addition, this would put a huge amount of upward pressure on the aft deck fitting and I was fearful that it would rip the arch right out of the deck or at least crack the deck as the base of the main davits was only about 2″ square, not counting pretty hefty below deck backup plates.   That’s not a lot of surface are to spread perhaps a thousand of pounds of upward pressure.

I thought about this for several days, and some sleepless moments at night I’ll admit, and settled on a plan.  I needed to offset the upward pressure on the davits I’d be applying by lashing a 50 gallon drum to the side of the radar arch and filling it with water, 50 gallons at 8.3lbs per gallon, over 400 pounds of downward pressure.   The theory was that while I was going to push up on the bent davit with many hundreds of pounds of pressure, this upward force would be somewhat offset by the pounds of water hanging on the side of the radar arch in the barrel.

I also ran a line from the top of the drum through a snatch block on the arch and down to a winch so I could release it when I was done.   As it slowly filled the line running to the arch made some alarming squeaking sounds.  Interestingly, even with all that weight the starboard stern only settled about an inch.

I also needed to protect my shiny new paint job from being scratched by the drum so I put a soft moving blanket between it and the new paint.  Here’s the setup.   Additionally, I drilled two small holes in the base of the barrel and attached a messenger line to a cleat on the dock so that after I was done the water would slowly drain out and I’d be able to turn the barrel over and drain it.  My fear was that the barrel would be too heavy to deal with and I wouldn’t be able to retrieve it.

I also prepared a 4×4″ post that was cut to the right height and attached plywood shims on the top of the post to ensure that it would not slip off of the stainless tube that I would be pushing against.   If the post was to slip off of the tube, it would ram right through the solar panel and put a big hole in it.   That would really have made me sad.

I used a car jack, rated at 6,000 lbs and put that on some heavy timbers so that it wouldn’t be able to move as I pumped up the pressure.  The jack has wheels and I was afraid that it would slip out as I jacked it up so I chose a timber that would rest securely between the back wheels. The moment of truth.  I pumped the jack up and up, wincing with every pull on the lever, expecting to hear the cracking of the deck or perhaps a weld breaking.  I didn’t.  I should note that I removed the bolts holding the aft end of the solar panel in place out of fear that the movement would put too much stress on the aft end of the panel and break the bolts or, worse,  the panel. After several rounds of applying pressure with the jack and then releasing it, I the stepped back and viewed the davits from several vantage points to see if it was level again.   I took a spirit level to the swim platform and compared that to the davits.

I looked at the rig from on Pandora’s deck, from a nearby dock and every which way I could think of and was pretty convinced that it was level again.   As nothing is level on a floating boat, it was hard to be sure but it seemed to be about right.

Frankly, I still can’t believe that it worked but I guess it did.  Whew!  No, make that double whew.

Amazing, actually.

So, for the third time in so many months, Pandora is back on the hard again.  Big boat, big projects await.  My mother says I’m big.  Perhaps she’d feel differently if she saw Pandora. so how much does a dink full of water weigh?   A LOT….

And now I won’t worry so much when I climb into the dink when it’s strung up in the davits.  Now I know that it takes at least 40o lbs to bend the davits and as the photos above shows, compared to Pandora I’m a long way south of that figure.

And, speaking of south, Pandora will be a long way north of south for the winter.

Say it isn’t so.

5 responses to “So, how much does a dink full of water weigh?

  1. Therefore, you will not be in Antigua this April when we complete our circumnavigation – so sad to miss you. We are in Port Mathurin, Rodrigues, Indian Ocean.

  2. George R. Hallenbeck

    Interesting engineering feet. Hope you can
    explain the large weight concept sometime.
    Pictures were a big help.

    • The idea behind the weight is to have it pull down on the arch with several hundred pounds of pressure to partially offset the upward pressure of the jack. I now see that i was unclear. I’ll re-edit the post to make it clearer.

  3. For goodness sake, this sucks! I am so sorry all this has happened! You’re such an innovator and so creative, so at least there’s that. Hang in there, 2019 will be Pandora’s year to shine!

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