Judging by the articles on the MoA website and the Web, it appears generally acknowledged that the Ardic heater which as installed by Nimbus, is less than effective at heating the cabins.  We had the heater unit serviced last winter by the local agent and whilst resolved the sooty deposits on the stern, the heating was no better.  It appears that in pre heating the engine, heat the fresh water and the cabin is beyond the capabilities of the system unless also running the engine.  The basic problem is that the system initially heats the cast iron mass of the engine which I believe takes 3kW, therefore the temperature of the air to the cabin is cool to say the least.  The pipework diagram in the manual suggests that this should not be the case, but on a cold day working on the engine with the heating on, the engine was starting heating up but the cabin was not.

After trawling the internet for a solution that did not involve replacing the entire system to no avail, we decided to make a major modification to the pipework.  We did however have the revised pipework scheme reviewed by the local agent, who helpfully gave me a contact number for an engineer that was employed by Ardic and now with Eberspacher UK.

The engineer when approached made an interesting if somewhat alarming statement in a mail, I quote as follows:

We would recommend removing your Ardic heater from the engine circuit totally. If the heater is switched on and the engine is not started then not only is the engine acting as a big heat sink (approx 3kW) but if the engine heats up and cools without running condensation, builds up within the engine, if the engine is not run for some time the oil can run away from the top end causing excess wear when the engine is eventually re started.

The other issues are opening your engines cooling circuit to the entire heating circuit adds many more leak possibilities, removing too much heat from an engine will cause it to run inefficiently, if the water returning from the heating system is too cool it can create excess cylinder bore wear and deformation on the first cylinder.

Generally the engine header tank is also lower than the highest component in the heating system leaving half the system full of air and running inefficiently also making it very awkward to bleed and keep bled.

Removing the engine and fitting a remote header tank will stop all of the above issues. Our marine dealer on the south coast has done in excess of 60 Maxi and Nimbus conversions to alleviate this problem.

Based on the above comments we decided to modify the system pipework so that the engine still heats the fresh water in the calorifier and nothing else.  This option only partially resolves the problem of cooler water returning to the engine by reducing the pipework and eliminating the heater unit.  However we took the view that the calorifier  being heated by the engine was well worth keeping and normal on boats.  A header tank was fitted to the heater circuit so that the heater only heated the air for the cabins, before and after pipework system diagrams are as follows:

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The header tank can be  sourced from a local agent for automotive/marine heating with 2 inlet/outlets and a pressure release cap and should be located above and as close to the heater as possible with access for top up of the 50:50 water/antifreeze mix.  The aft inboard end of the cockpit locker bulkhead above the floor boards cover is suitable.

Since the modification, the calorifier heats up as before, although we do not have the facility of heating domestic water with the heater.  We have also lost the facility of warming the cabin with air heated by the engine.  However the cabin heater vents now give out warm air which is acceptable, although still not as effective as a warm air heater system such as Mikuni or Eberspacher.  We judge the modification a success and have avoided the worst of the potential dangers as outlined by the engineer.

Jim & Eric Sey of Second Rebellion

Maxi 1100 “Second Rebellion”

Navigation electronics, a cost effective option to having GPS plotters at both the navigation table and at the helm

The 2001 yacht was purchased in August 2008 and it came with a Raymarine RC530 colour plotter at the chart table, a Raytheon RL70 at the helm and a Seatalk interface which integrated the radar.  Unfortunately the helm plotter was not readable in daylight, so something had to be done.

• As the yacht had the seatalk interface and all other instruments/radar were Raymarine, we only considered that manufacturer’s equipment.
• We established that the radar scanner would be compatible with the current Raymarine E80 range of plotters and we could also have AIS, however the E80 equipment would not interface with the RC530 existing plotter.
• The obvious but expensive option was to replace both plotters.  However, Raymarine in common with other manufacturers, do not market a repeater for the plotter, you just buy 2 of them at around £2k each.
• However with the help of a friendly engineer in the local agent, it was revealed that you did not need a second plotter.  An E80 (or E120) at the helm with a VGA cable to an inexpensive LCD computer screen (they are all 12volt), can be used to feed the screen at the chart table linked with a Raymarine keyboard, which they market for the huge screens on power boats.  This option is actually better than 2 E80’s, as the PC screen can be larger and as in ours in “letter format”, which is ideal for split screen plotter/data/radar viewing.  I believe that the latest “C” series plotters may also have the repeater facility.
• As it happened we had a spare PC screen so it cost us nothing, the screen swivel mount cost about £20 and the quite neat keyboard was £300 plus VAT, quite a saving on £2k and a better option all round.
• All E80 functions can be duplicated below using the keyboard and the PC screen can be swivelled to the saloon to entertain the grandchildren with DVD’s (from a player) with surround sound through the boat audio system.
• The only downside is that manipulating the data from the chart table, also changes the plotter screen at the helm.
• Both old plotters found a ready market on E-Bay, to help offset the cost of the new equipment.

The system has been extensively used for 3 seasons over 5knm without problems and a recent comment from the local agent for Raymarine was “I don’t know why more people don’t go this route”.  I do…they just do not know the option is available.

Jim & Eric Sey

Pics:

1. Nav. station, Mount, and Keyboard in use

1. Keyboard parked

Fuel tank sender for a maxi 1000

My fuel tank sender had become increasing erratic so a replacement was required.  The stainless steel tank on the Maxi 1000 has a large cut out for the tank sender used as original equipment – quite unlike the senders regularly available.  After months of trying through Maxi to get in touch with the original Swedish supplier, my son Nick (works at Force 4 Lymington) came up with a simple solution from Wema.  They produce a kit that fits in the hole and allows use of their regular Wema senders.  Part numbers are FL-2 163010 and FLS-U 54MM 163303 for the adapter kit and then S3-E250 for the tank sender.

Thanks to Julian Trimming for this information June 2011

Boat PC on our Maxi 1000 – Navigation, AIS, Weather, emails and TV

I like to keep things simple on the boat as everybody can operate simple things and they tend not to fail in the wrong moment but over the years the laptop started to become a constant companion on longer trips. Initially just to be able to get a weather forcast from the Internet but later I added a NASA AIS receiver for safer Channel crossings and soon things started to get complicated. Not because of the technical solution but there was no safe place for the laptop to be kept while sailing, hence it was not much use with the AIS in more than very light winds.

The dilema I got into was that I was not prepared to spend all the money on a chart plotter and electronics charts if I would still use paper for everyday navigation and that I liked the additonal benefits a laptop/PC has over a plotter, like Internet, iTunes, DVDs for the kids etc. The solution seemed to find a home for the laptop that would be safe, the screen being viewable while the keyboard is protected - who want's to go down in his oilies and flood the laptop.

Soon I found myself scanning the internet on Car PC options and TFT screens as I couldn't come up with a good solution for the laptop that would not involve a separate screen and I learned that laptops are quite power hungry. I did also look at those boat PC packages that are on offer but found these too expensive and not surprisingly the components used look exactly like those on the Car PC websites.