Beneteau water tank inspection hatch removal tool

Skylark

Skylark

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Getting ready for launch, tried to fill my forward water tank today. According to the gauge on the panel it’s half full yet water is streaming out of the overflow. I’d like to check if filling, pushing a hose into the filler, is pressurising the tank due to poor ventilation or a blockage, pushing water into the overflow. The tank has an inspection hatch. A tool to open it would be X section. Each leg is about 90mm with 15mm width. It shouldn’t be a big problem to make a key out of wood but does anyone know if a proprietary product exists? Any thoughts as to why I’m seemingly only able to half fill the tank would be appreciated, too.
 
ithet said:
I think I used a strap wrench to undo the water tank inspection caps on my Beneteau.
Click to expand...

If it's like mine with an X on top you can't get a strap wrench on it - inset into polyethylene tank moulding. One of mine undoes easily, other one completely locked: can't get it off at all. Even with an improvised X-tool just bends the plastic - gave up before it was damaged.
 
jwilson said:
.................One of mine undoes easily, other one completely locked: can't get it off at all. Even with an improvised X-tool just bends the plastic - gave up before it was damaged.
Click to expand...

Oh dear, this isn't an inspiring comment! Sounds like I've made a wooden X-tool today and I'll probably go back to the boat (almost 200 mile round trip) over the weekend. My launch is next Friday.

The boat is 2013 and relatively lightly used, 210 hours on the engine. The gauge display is fully electronic, one screen with a toggle switch to show engine, domestic and bow thruster battery voltage, fuel and water. As is often the case and especially after unanimous feedback, I'm now doubting myself as to whether I can remember the gauge ever reading full. I bought the boat new so it must have done (surely?).

So what may cause an error in the gauge reading? How does the tank sender work......is it similar to a fuel gauge, a float moving across a wire resistor?

I appreciate the responses, many thanks
 
My gauges work with three terminals through the side of the plastic tanks, obviously water connecting them internally gives one two or three green lights, or a red light when near empty.
 
I drilled a hole into the top of our tanks (2 x 200l), bought the appropriate insert, blocked off with a threaded fitting - take threaded fitting out, use a dipstick, piece of dowel (and we have a simple sight tube for fuel).

Jonathan
 
I know three different types of water level gauge sender:
1) The most common is like the fuel tank sender in a car. A wire rod is pivoted and has a float on its outer end and moves a contact over a wire wound resistor.
2) The type that fits from the top of the tank and has its electrical parts in a sealed vertical tube. A float on the outside contains a magnet which I think just closes reed switches inside the tube to give a reading in a series of steps, with each level providing a different resistance.
3) The type where contact points are fitted a various heights inside the tank and and an electric current passes between them only when they are immersed. I have ones that have eleven contacts, giving me ten lights when the tank is full.

Type number three is the Kemo Water Level Indicator type, and Maplins are now selling them at a bargain £14.99 https://www.maplin.co.uk/p/kemo-water-level-indicator-n16dd (£25 on Amazon)
I wrote up how to fit these in PBO August 2016. They run on 3 volts but I powered mine from the boat's 12 volt system using a cheap buck converter. They make a simple and reliable water level system. I used a piece of plastic drain rod with the eleven thin wires terminated on equally spaced brass screws as an in-tank sender. If you want one, hurry because Maplins have very few left.
 
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My Benny came with a homemade hatch remover but it didn't work. I could, however, drift thechatch open with judicious use of a hammer and a piece of 2 x 1.
 
Norman_E said:
I know three different types of water level gauge sender:
1) The most common is like the fuel tank sender in a car. A wire rod is pivoted and has a float on its outer end and moves a contact over a wire wound resistor.
2) The type that fits from the top of the tank and has its electrical parts in a sealed vertical tube. A float on the outside contains a magnet which I think just closes reed switches inside the tube to give a reading in a series of steps, with each level providing a different resistance.
3) The type where contact points are fitted a various heights inside the tank and and an electric current passes between them only when they are immersed. I have ones that have eleven contacts, giving me ten lights when the tank is full.

Type number three is the Kemo Water Level Indicator type, and Maplins are now selling them at a bargain £14.99 https://www.maplin.co.uk/p/kemo-water-level-indicator-n16dd (£25 on Amazon)
I wrote up how to fit these in PBO August 2016. They run on 3 volts but I powered mine from the boat's 12 volt system using a cheap buck converter. They make a simple and reliable water level system. I used a piece of plastic drain rod with the eleven thin wires terminated on equally spaced brass screws as an in-tank sender. If you want one, hurry because Maplins have very few left.
Click to expand...

There are very few Maplins left.
 
Hello,

The tool I use to inspect the tanks is like the one in the picture. It never fails!

tank_tool[1].jpg

I have a Beneteau and the water tank level senders have taken a lot of effort from me to resolve their poor performance. I have a complete description of how they work in my forum (I assume you have the same type of VDO gauge). I made arduino senders last summer but I did not like their delayed response. So I made new analogue senders which I will test in 2 weeks from now when I arrive to Greece. If you read the following post you will understand what I am referring to:

https://www.vela-navega.com/index.php/tank-monitors

Regards, Luis
 
Many thanks to all who have taken the trouble to reply, much appreciated.

Boats never cease to amaze me with their quirky traits. I made a T section key using 15mm ply, drilled, screwed and glued to a 12 inch long handle. I succeeded in breaking it before the hatch lost its grip on the tank. Frustrating. So next, I removed the overflow pipe and put the hose pipe back in the filler, this time with a low flow rate. Sure enough, the gauge was correct and the tank was half full. I continued to fill, slowly, until water came out of the overflow. The gauge now reads full. I can only conclude that filling the tank with high flow from the hose pipe does indeed pressurise the tank and push water out of the overflow. Never noticed that before.

Here's a picture of the tank inspection hatch and the gauge sender connections.

IMG_0394.jpg


IMG_0398.jpg


I don't like the fact that I can't remove the inspection cover........but.......I'd like it less if I damaged it trying to undo it! Now pondering whether to make a more robust key, or leave well alone citing "if it ain't broke, don't fix it"

Luis - I've just spent a very pleasant hour reading your website.
 
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