On Board with Mark Corke

Sigma Lights

 

I'm a big fan of LED lights and they are now so sophisticated that I can't really fathom why anyone would want to continue to use regular bulbs of any sort aboard. LED's use about a fifth of the power of regular incandescent bulbs yet produce as much light. Regular light bulbs are very good at producing heat which accounts for something like 90% of the energy consumed while light is almost a by product. That heat can degrade head linings and the extra heat can be a real bear especially in the warmer weather which may require running the A/C unit to suck it out of the cabin.

Some time back I upgraded the lights on Mallard my Golant gaffer from incandescent to LED lights. At that time I used the Hatteras lights from Imtra which made a vast difference to the interior of the boat. Not only was I able to install a total of five lights which consumed less electricity that the two previously installed but the light output was constantly variable from off to wow. As I was installing the lights essentially from the word go I ran new cables to each of the fittings; four wires were required, two for the power and a second two for the dimming circuit making four in all. Of course in my installation where the cables were essentially surface mounted the extra couple of wires was not an issue but what if the wires are hidden behind a headliner, furniture or other obstacle as might well be the case in an older boat. Thankfully Imtra have addressed that and introduced the Sigma light. About the size of a small hockey puck the light can either be surface mounted or set flush into the over head panel. The best part about the light however is that it is compatible with many halogen digital dimmers and as such can be used with just two wires making retrofitting a very easy job. The light operates on any voltage from 12 to 40 volts DC and although not cheap with a starting price of $160 it is a quality product. Available in both warm and cool white color temperatures the lights have a useful lifespan of 50'000 hours so conceivably would outlast the average boat by a factor of 20.

 

The Sigma series is available in small, large and surface-mounted configurations. Sigma Small, with a 2-9/16” (65mm) cut-out, is sized to be a drop-in replacement for many of the popular 20 Watt halogen recessed spots that have been used in the industry for years. Sigma Large contains the same light engine as Sigma Small and is supplied with a larger diameter trim ring and special adapter plate that allows its placement in hole cut-outs from 2-9/16” (65mm) through 3-7/16” (87mm). Sigma Surface Mount is designed for surface-mount installations and is ideally suited for under cabinets or ceilings with restricted recess depth. The fixtures can be installed with included springs or screw-mounted.

 

Water heater Anode - part 2

A couple of posts back I wrote about replacing the anode in an on board hot water heater. I seem to have a struck a chord and as I thought many correspondents did not even know that they had an anode in their water heater. Interestingly many water heater manufacturers also keep fairly quiet about the need for replacement anodes on a fairly regular basis presumably because they can make more money selling water heaters than anodes. Unlike the anodes in engine heat exchangers, oil coolers and so forth the anodes in water heaters are magnesium not zinc. There is a lot of chatter on some of the internet forums where 'experts' are telling folks to use zinc which is incorrect. Every water heater that I have ever worked on has a aluminum as a common ingredient on there insides and zinc is too close to aluminum on the galvanic scale to do any good, magnesium is farther down the scale and is less noble than the aluminum which it protects.

 

Many boats are fitted with six gallon water heaters from the likes of Seaward (shown above) or Force Ten and so on. These compact oblong water heaters do sterling service but DO NOT come supplied with a sacrificial anode as standard so from the very moment that they are installed and filled with water they start to corrode from the insides out. The first thing to pack up is often the heating element and this is often the only indication that something amiss to the boat owner and a new water heater is soon required thereafter. Getting the heater out can be a real bear; often installed in the engine room there is frequently little space to spare. Thankfully there is an answer and that is that you can save yourself a big headache and a ton of cash by installing an anode. The six gallon heaters mentioned above have a drain valve which is great when the time comes to winterize the boat but this can be removed and an anode screwed in in it's place, literally a five minute job. The part number for this is 74556, a 4 inch anode which costs $20 or less from one of the many online retailers – far cheaper and a lot less hassle than having to change the entire water heater. The other benefit of this is that with the anode in place of the tap the anode has to be removed to drain the tank so you can see at a glance how much is eroded and replace it if it is more than 50% gone.

 

While on the subject of anode protection I changed the pencil anode in the engine heat exchanger last weekend and after 100 hours of running you it's not hard to tell the old from the new replacement. This anode cost me $16 from Boatzincs who offer a vast array of zincs to suit almost any application. Cheap insurance I'd say and if you thought I was whining on a bit about the cost of a replacement water heater I would hate to even contemplate the cost of replacement engine parts if replacing this anode were overlooked.