NeilPayne
New Member
Can anyone tell me the ideal location for a waste holding tank on a 1997 Bavaria 38, 3 cabin 2 heads option?
Bavaria 38 Holding Tank
- Thread starter NeilPayne
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Tranona
Well-Known Member
The original would probably have been a tank under the saloon berth with a pumped system as on my 2001 37. Not sure of your loo compartment layout, but i did not have the standard one fitted - thought of 5m of sewage filled pipe running across the boat is not nice, so fitted a gravity tank in the locker behind the vanity unit.
A gravity tank is the simplest system, but you need to have bulkhead space above the waterline to fit one. Otherwise you will have to find space in an underbunk locker in an adjacent cabin and plumb in a pumped system. You need to find space for about 50l+ to make it worthwhile. You will find good schematics of different systems on the Tek Tanks website. Be aware this is not a trivial undertaking, either work involved or cost. A budget of around £1k for a custom tank , fittings, valves, pump new piping etc. will not be overgenerous.
A gravity tank is the simplest system, but you need to have bulkhead space above the waterline to fit one. Otherwise you will have to find space in an underbunk locker in an adjacent cabin and plumb in a pumped system. You need to find space for about 50l+ to make it worthwhile. You will find good schematics of different systems on the Tek Tanks website. Be aware this is not a trivial undertaking, either work involved or cost. A budget of around £1k for a custom tank , fittings, valves, pump new piping etc. will not be overgenerous.
nigelmercier
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Are you intending to use it with both heads?
NeilPayne
New Member
Using it with both heads would be the ideal solution. If only one head I would like it to be the aft heads - off the saloon.
Tranona
Well-Known Member
You may have difficulty in finding a good location for the tank from the aft loo as there is unlikely to be room in the aft cabin because all the space is taken up by the water tank. My 37 has a very similar aft loo, but there is space in the locker behind the vanity unit where the water pump and valves are. These have to be moved, but there is room for a good size gravity tank there - mine is 65 litres.
As I said, the factory fit tank was under the saloon settee just behind the forward bulkhead, which is OK for a forward loo, but means you have to run a 38mm pipe all the way across the boat for the aft loo. An alternative might be under the forecabin berths, but that is difficult if you have the second water tank there as the only space left has the transducers in it and you need access to those.
Quite normal to only have holding tank on one loo because of the complexity of pipework and space limitations to fit a tank capable of servicing two loos. In the latest boats (not just Bavarias) loo compartments have been redesigned to create space for a gravity tank, usually under the sidedeck or in a bulkhead locker, but clearly not possible on an existing boat.
As I said, the factory fit tank was under the saloon settee just behind the forward bulkhead, which is OK for a forward loo, but means you have to run a 38mm pipe all the way across the boat for the aft loo. An alternative might be under the forecabin berths, but that is difficult if you have the second water tank there as the only space left has the transducers in it and you need access to those.
Quite normal to only have holding tank on one loo because of the complexity of pipework and space limitations to fit a tank capable of servicing two loos. In the latest boats (not just Bavarias) loo compartments have been redesigned to create space for a gravity tank, usually under the sidedeck or in a bulkhead locker, but clearly not possible on an existing boat.
NeilPayne
New Member
Tranona,
Thanks for info. I think your 37 heads layout must be different to my 38. Certainly not enough room behind the vanity unit for a tank of any size. So far the best options I can see are;
1) To use the hanging locker space in the port side aft cabin for a gravity tank serving the aft heads
2) Under the forward end of the saloon seating for a pumped tank serving the forward heads.
Using the aft hanging locker would not be a problem as we normally sail with only 2 on board and at most 4.
Might be able to get something under the vainty unit in the aft heads if I re-jig all of the pipework.
Tranona
Well-Known Member
Yes, I think my loo is a different layout as it has an extension into the aft cabin, reducing the size of the clothes locker there.
If you are prepared to sacrifice that clothes locker it would be a good solution as it would be easy to run the pipe from the loo outlet to the bottom of the tank with an internal stack pipe, then an outlet back to the existing through hull and valve. A pump out fitting would be easy to arrange on the side deck. Make sure you design the top of the tank such that you have the inspection hatch immediately above the outlet so that you can rod it easily if you get a blockage.
You would have essentially the same arrangement as mine, but the tank in the aft cabin rather than in the locker in the loo. Don't think you will get a standard shape tank in there - Vetus do some, so have a look at them. A custom tank will allow you to maximise the capacity in the space available. Tek Tanks will help you design the best arrangement for the space.
65 litres is enough for 2 people for "normal" use. A tank for the forward loo is a much more complex job as you need additional valves, a pump and possibly a macerator plus an extra skin fitting. There was a good article in a recent PBO on fitting that sort of arrangement in a Moody which will help you understand what is involved.
If you are prepared to sacrifice that clothes locker it would be a good solution as it would be easy to run the pipe from the loo outlet to the bottom of the tank with an internal stack pipe, then an outlet back to the existing through hull and valve. A pump out fitting would be easy to arrange on the side deck. Make sure you design the top of the tank such that you have the inspection hatch immediately above the outlet so that you can rod it easily if you get a blockage.
You would have essentially the same arrangement as mine, but the tank in the aft cabin rather than in the locker in the loo. Don't think you will get a standard shape tank in there - Vetus do some, so have a look at them. A custom tank will allow you to maximise the capacity in the space available. Tek Tanks will help you design the best arrangement for the space.
65 litres is enough for 2 people for "normal" use. A tank for the forward loo is a much more complex job as you need additional valves, a pump and possibly a macerator plus an extra skin fitting. There was a good article in a recent PBO on fitting that sort of arrangement in a Moody which will help you understand what is involved.