Holding Tank for LM30

[Argyller]

I'm now planning for a holding tank on my recently acquired challenge.

From some cardboard modelling, I reckon I might just about get a 50 litre tank under the fore cabin.

Has anyone got a tank located elsewhere? For example, under the wheelhouse. anything larger and higher, concerns me regarding stability.
Opinions and experiences please with flexible waste tanks?

Thanks,

Ron Dunbar

[Charles]

We fitted an RM69 buffer tank. It's only 25 litres, but it's enough to cope with swinging at anchor overnight in an estuary, and it can be pumped out at sea. Suggest you take a look at the thread LM27 Holding Tank on page 11 of the Advice Sought section of this web site.
Charles

[Brian & Glenda]

According to the sales brochure posted elsewhere on this site, a 75 litre black water tank was an option for the LM30, and standard equipment on the LM32.

Our 1983 LM32's black water tank, is located below a large triangular wooden floor panel at the entrance to the fore cabin. Below that wooden floor panel, is the securely screwed down fiberglass lid for the waste tank.

Just forward of that, and below the V berth mattress is another wooden lid that opens into a storage compartment. A Y valve is located in that forward compartment that allows either the Henderson Mark 5 electric diaphragm pump that is mounted within to discharge the contents out the through-hull (which is located about five inches below the water line and about two feet aft of the prow), or with the Y valve in the alternate position, the contents can be sucked directly from the tank and up a discharge outlet which used to be located in the anchor locker. I subsequently moved this fitting to be flush fit on the fore deck.

The Henderson pump is mounted within this forward compartment, on the backside of the bulkhead between these two compartments. I have noted in some images of other persons boats, that some LM32s have a manual pump mounted through this bulkhead, instead of an electric pump within. I sometimes think a manual pump would be a better solution. (No battery draw, and you can 'feel' when the tank is empty.)

By peering into the forward compartment, one can see the forward wall of the black water tank. The tanks inlet, outlet, and vent enter the tank through at this point.

My boat did not have, but I did subsequently added when I replaced all of my black water piping, an anti-siphon valve on the path to the through hull discharge. This will prevent any siphoning and filling of the waste tank if I ever left the through hull valve open.

The tank vent was also in a very odd spot ... just above the water line, but within the bow wave! It's 5/8" line now comes up the bow, through the bottom of the upper level of the anchor locker, and exits the side of the hull a few inches below the deck level.

As I never knew what the level was of the waste in this tank, I also mounted a SCAD tank monitor with a separate capacitive level sensor through the fiberglass lid of my holding tank, and this has proved to be quite useful. www.scadtech.com/tank_monitors (no affiliation - just happy customer.)

Hope that helps! I can send some photos if you like. Just let me know if you want any.

Brian.