Saturday, December 27, 2014

Deck Light Improvement

Just in case you aren't yet sick of hearing stories about my deck light, I have one more for you.  This time it is an improvement to the existing system.

After finally getting the deck light working, I just couldn't leave well enough alone.  The deck light is a pretty standard 12 volt, 30 watt, PAR 36 incandescent bulb.  What that means is that it takes approximately 2.5 amps of current to run the light when it is on.  While that is fine if you have an infinite supply of energy, on a sailboat under sail that is a lot of power being drained from the house battery bank.  And being an incandescent bulb, most of that energy goes to producing heat and not light.

Since I have been replacing the most used incandescent lights on the boat with LED bulbs, I decided to look around and see if I could find a reasonable cost replacement for this relatively power hungry bulb.  Consulting the oracle, I found a number of LED 12 volt PAR36 bulbs.  Unfortunately a lot of the bulbs I found were for indoor use only.  Since my deck light is held up by a simple, and not weather tight, plastic frame, I definitely need an outdoor bulb.  I found a few relatively expensive bulbs (in the $60 U.S. price range) and then came across a more reasonable option on Amazon.

The bulb I found consisted of the standard PAR 36 glass bulb housing.  Inside, instead of an incandescent filament, is a circuit board with a bunch of LED's mounted on it (and I assume some other circuitry that you can't see).  The result is an LED bulb with the same physical characteristics and weather protection as the bulb I am trying to replace.  And at $26, it is only twice the price of a replacement incandescent bulb.  So, I ordered one.

LED Par36 Bulb

I ordered it through Amazon and the order was fulfilled via EverSale.  To my amazement, having ordered it just before Christmas, it arrived the day after Christmas...probably the fastest "standard" shipping I have ever had.

So, today I went up the mast to the deck light again.  I swapped out the incandescent bulb for this new LED one, making sure I applied some dielectric grease to the connectors when I installed the new one (I hold out hope that this one will last a while and I won't have to go back up there again anytime soon).  I test the light and it lights up and seems brighter than the original bulb, but during the daytime it is hard to tell.

Another issue I had with the original bulb is that, while it is technically a flood light, it acted more like a spot light. The light produced by the bulb created a well lit 4 foot diameter circle on the forward bridge deck and then quickly faded the further out you went from that circle.  Given that my catamaran is just over 21 foot wide, a better light spread would be nice.

Finally, after it got dark, I went out to see how well this new LED replacement works...

To say that I'm happy with the result is an understatement. The light is certainly brighter than the original bulb.  At 9 watts (.75 amps), it consumes less than a third of the power of the original.  And a nice side effect is that the light produced by the bulb is much more even across the entire deck of the boat (as you can see in the picture above). I'm sure that this will make working on the deck at night a much safer experience.

So far I have to give this bulb a thumbs up.


  1. The best place we've found to buy LEDs is at Cheap, great selection, excellent service.

    S/V Kintala

    1. Hey Deb,

      You had recommended them before so I looked there, but didn't find a weatherproof PAR 36 bulb when I searched their site.

      Definitely need a weatherproof bulb for a deck light.