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Messages - dlincoln

#1
Isn't Magic Eraser pretty much like a very fine grit sandpaper?  It does a great job cleaning, but you might be removing gel coat every time you use it.  I recently used one to remove permanent marker from a table top, and i noticed that it removed the finish in places and left swirl marks where I had used it.  My opinion, save it for the occasional tough stuff but don't use it as an everyday cleaner.

Don
#2
Main Message Board / Re: New Mainsail Management
July 16, 2009, 07:16:17 PM
You obviously are a whiz with the sewing machine.  This looks VERY nice!!  Well done! :clap
#3
Main Message Board / Re: Lighting upgrade - LEDs
May 31, 2009, 12:13:31 PM
Sorry I'm a little late to the discussion, but I am a new member here.  I work in the LED industry - my company designs and manufactures LED street lights (but not marine lamps, so I have no recommendation of a good vs. a bad brand).  I would like to caution everyone out there considering replacement projects to be very careful about what they buy. 

There is a LOT of junk available right now, and it is currently very difficult to tell the good from the bad when it comes to LED fixtures or replacement kits just by reading the packaging.  Heat management is the key to the performance of these new high-output LED products like what we're discussing here.  Most companies do not do a good job of extracting the heat from the LEDs properly, and the result is reduced brightness and reduced life of the product.  A good thermal bond between the base of the LED and the heat sink is critical to how well it works, but unfortunately there is no way of telling how good this bond is when you purchase a product, even if you tear it apart.  Most LED products will be equally as bright when you first turn them on, however after two hours or so of operation, products that have poor heat management will begin to dim noticeably as the LEDs start to lose more of their energy to heat.  If the LED assembly has good thermal design, then there will be no noticeable loss of light output.  We have done extensive testing on several consumer products (again, not marine products, but many commercial and some residential products), and I have not seen ANY replacement products for screw-in or bayonet-style bulbs that exhibit good thermal design - most of the ones I have evaluated dim to about 50% of their initial output after running for a couple of hours (they return to full brightness after turning off and allowing to cool).  This also means that the LED is cooking itself, and this will affect the life of the product.  This dimming is annoying when lighting your cabin, but may be downright dangerous for an anchor or running light (white LEDs are most affected - reds are less difficult to manage).

Much of this problem stems from the consumer's expectations of lighting.  We are all used to the fixture being the more expensive part and the associated bulb being the cheap commodity.  So companies are all trying to develop screw-in replacements because that's what people are used to.  With LEDs, the LEDs themselves are the really expensive part, and ideally should be integral to a fixture or housing in order to properly design heat extraction.  By being fixated on having replaceable LEDs "bulbs", it limits the potential options for good thermal management.  A decent LED fixture design should give you 30,000 - 50,000 hours of use (LED lifetime is defined as a 30% reduction in total initial lumen output, instead of a burn-out condition like with traditional bulbs).  And if you do the math, this is a significant amount of time in the world of boating, and may represent the lifetime of the boat for certain lights, like the anchor light. 

There are some new and some forthcoming standards from the Dept. of Energy/EnergyStar that will finally start to weed out the garbage from the good LED products available, so in the near future look for the EnergyStar label when shopping for new LED products.

So after all of this rambling, here are a couple of guidelines when considering LEDs right now:

1. Unfortunately, a generalization at this point in time is that you get what you pay for.  There are some $100 LED solutions out there and some $20 LED solutions.  Beware the $20 product. 
2.  Do not believe manufacturer claims of performance/life of their products.  The DOE has consistently documented that most of the claims are untrue, and the industry is in a "rogue" phase right now until some solid standards are put in place.  If you really want to replace your lights with LED products, buy one, install it, and let it run for 2 hours or longer and see if significant dimming has taken place (helps to have a light meter for this, but keep in mind that most light meters are not calibrated for LED light, so this will just be an A to B comparison). 

Hope some of this makes sense.

Don