Large Plastimo Flexible Water Tank

Published date: March 30, 2011
  • Boat Type: Boat Type

In our Macgregor, we plan multi day stays in remote coves in efforts to get away from the stresses of working society. With that in mind the Admiral does not want to leave the comforts of running hot water and showers behind, hence the need for a large water tank. Based on previous posts, it looks like others have used the Pastimo flexible water tanks. I like the idea of using every nook and cranny in the boat, and I've always found the space under the aft bunk to have little value, until now.

Plastimo makes several flexible water tanks of different sizes and shapes. One of their largest tanks is their 200L, rectangular tank which when fully expanded - 27.3" x 68.25" x 9.75" holds 52 gallons of water. The area between the water ballast tanks in the boat is wide enough to both accommodate the tank and also restrict the tank from going too far, however it is only about 6" tall at best. This means the 52 gallon tank will actually only hold about 30 gallons of water. Also due to the geometry of the area and tank design, I figure there is probably 2 gallons of unusable water that will not drain out of the tank when near empty.

Keep in mind, 30 gallons of water is going to increase the weight of the boat by about 250 pounds, not too much of a problem when sailing (if well secured) but you probably don't want to carry that around when trailering.

The 200L tank fits under the bunk area with just about 5 inches to spare. I was going to line the area with some old carpet, but after looking at the double lined construction of the tank - there is no probable reason for the tank to rupture as long as the area is free of debris. Also I felt that carpeting the area might make the tank slide easier and I want the high floor friction. I prepared the floor by sanding it and then washing it real good with virgin lacquer thinner.

I pre-fit the tank and marked the factory mounting locations. At each of the eight mounting points, I bonded a block of 2x4 wood to the floor using two part Jeffco 1307LV epoxy resin and cotton structural flox. The tank tabs are then screwed to the wooden blocks for a secure fit.


Published by: u12fly

Model Year: 2006
Photo Caption: Tank installed - looking aft from cabin

Close up of mounting block bonded in place

Tank secured in place


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