Worried about my holding tank coming loose

Apr 16, 2021
13
Hunter 340 New Bern
I am a new liveaboard owner of a 2000 Hunter 340. The holding tank and the diesel tank are secured by flimsy straps. It's not like the tanks are in deep recesses. Has anyone had one come completely loose? Should I do something preemptive?
holding tank.jpg
 
Feb 14, 2014
5,716
Hunter 430 Waveland, MS
Plastic tanks need to flex and expand. Careful how you strap them down.
Jim...

PS: Mine are fixed in place, and metal
 
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Nov 8, 2007
1,397
Hunter 27_75-84 Sandusky Harbor Marina, Ohio
Yeah. I’m with if it’s not broken too bad, don’t fix it too much. If I were planning a blue water cruise, I might go ahead and put a second restraint on it. If the strap looks good, I’d leave it as is for coastal cruising.
 
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RoyS

.
Jun 3, 2012
1,218
Hunter 33 Steamboat Wharf, Hull, MA
It looks like it is sitting in a wood frame, and the strap keeps it in the frame...been sitting there for 21 years...

leave it alone.
Agree with Tally Ho, mostly. I would take a close look at the wooden frame to be certain that it is solid and fastened well. Otherwise your installation looks normal.
 
Oct 22, 2014
16,145
CAL 35 Cruiser moored EVERETT WA
Welcome Mike to SBO.
Living aboard in harbor, or along the coast is most often gentle on our boats.
Your Hunter was not intended to go out on the open ocean in Force 10 storms, climbing 30ft breaking waves where strapping the holding tank down would be a serious concern, behind many more.
In most cases when faced with the possibility of a severe storm condition, the skipper would pump a full holding tank overboard to lighten the load on his boat. After, of course, having emptied his own tank.
In your case, living off the grid aboard your boat your likely going to be ok.

On your new to you 20 something old boat, I would be focusing on the rigging, through hulls, motor, sails, and hull. Those are the critical issues that keep the water out and the boat moving.
 
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Dec 2, 1997
8,130
- - LIttle Rock
Plastic tanks need to flex and expand. Careful how you strap them down.
I disagree, Jim. Flexing and expanding leads to cracks. Water and waste weigh 8.333 lbs/gal. The best tanks have walls thick enough to support that much weight, but most off-the-shelf tanks sold in marine catalogs and stores have walls that are barely 1/4" thick. Tank mfrs strongly recommend that the tank walls be supported on all sides to PREVENT flexing.

--Peggie
 
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Feb 14, 2014
5,716
Hunter 430 Waveland, MS
Tank mfrs strongly recommend that the tank walls be supported on all sides to PREVENT flexing.
Thus, you made my point on this owner's tank.;)

If his Hold Tank is 50% full, in the Aft part of his boat near his Rudder Tube [white column on right side of picture]
Then the forces applied to the tank wall are MORE than just simple Weight/Mass of the contents.

In moderately High Seas, the tank walls will experience additional forces, MASS x Velocity of falling fluids inside.
This is called Momentum.

Thus, the reason most Tank mfrs want their Tanks supported, as you said.

His is not!
Jim...

PS:
Water and waste weigh 8.333 lbs/gal.
Not true if using Salt water flushes + poop + Toilet Paper.
 
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Apr 16, 2021
13
Hunter 340 New Bern
Anyway, thanks for the discussion. I have bought rolled-up yoga mats ($10 each from TJ Maxx) and inserted two on top. Same for the diesel tank. They apply light, distributed pressure down on the tank. I'll check if they're in place after a couple of sails. This is kind of a peace of mind thing. I tried.
Clipboard01.jpg
 
Feb 14, 2014
5,716
Hunter 430 Waveland, MS
Great idea with those mats!

You can even use your Yoga Mat, weather Deck side, for Sun Tanning.:pimp:

Sail with confidence...
Jim...
 
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Aug 15, 2011
31
Hunter 45 Legend Holland
My 1987 31' had both tanks supported the same way and it never came loose. The boat was raced on and across lake Michigan and never had any problems. probably in conditions it should not have been in like pounding into 50 knots of wind and 10 - 12 foot waves. I would be more concerned on things like the standing gear and Rudder. We broke 2 of them in the middle of lake Michigan electrolysis plays heck on steel especially if in salt water.