Steve's Last Chance Marina
|This page discusses electrical modifications and repairs
that have improved the safety, reliability and performance of the EWE BOAT.
Items marked in green text are cross referenced
with their respective sources at the bottom of the page. This month's features
- Get down to basics
- Up your voltage?
- A transistorized ignition for 6, 8 and 12 volt systems
- A shocking topic - spark plug cables!
- Fuses - gotta have 'em. Know where to put 'em?
- On the water you still need ground
- A scary story with a happy ending
|Basics - Electricity is measured in volts, watts and amps. Voltage represents the intensity of current in a circuit. Amperage is the amount of current in a circuit. Wattage is the rate at which current is used in a circuit. Resistance in a wire carrying current to an appliance reduces the voltage being delivered to an appliance. The longer the wire and the smaller its gauge, the greater the voltage drop. Excessive drop can reduce performance of electrical appliances. A 10% drop in current to lights is usually acceptable however, for electronic equipment, the drop should not exceed 3%. The wire size charts at the left give the recommended wire-gauge sizes for 12 volt DC, two wire systems for both 10% voltage drop and 3% voltage drops. Wire - You know that cheap wire you found at "All for a Buck" or "zip" speaker wire left over from your teenager's stereo system? DON'T USE IT IN YOUR BOAT. The best wire to use is tinned stranded wire made for marine environments. Boat US and many other marine supply houses carry this wire. Connectors - Crimp type connectors are fine for marine use as long as you recognize that many of these connectors have 2 crimp points, one at the wire/connector and the other at the connector colored insulator. The crimp at the connector colored insulator point provides strain relief . The best approach which is also the most time consuming, is to solder the wire to the connector. Note that if you are going for show, the crimp type of connector may get you docked a point.
|Up your voltage? - EWE BOAT has been a wonderful traveling companion but in years past after sustained running she would refuse to start until the engine cooled down. Bummer! This problem was solved by replacing the 6 volt battery with an 8 volt battery. An 8 volt battery is readily available from Exide or NAPA and is available in a variety of sizes. My engine starts on the first attempt every time and my lights are brighter. If you go to 8 volts be sure to adjust the charging rate on your generator for a max of 15 amps. Now the $ 64 question, how do you charge an 8 volt battery? With an 8 volt battery charger! This one is called the "Super Smart" Battery Tender. It is manufactured by a company called Deltran. I purchased it from Halon Marketing in Pennsylvania. Deltran also makes a 6 and 12 volt model.
|A transistorized ignition for 6, 8 and 12 volt systems - THIS THING IS GREAT! We found this kit in Belgium. It is basically a transistorized set of points that unloads your points and saturates your ignition coil. You get to keep your existing distributor, points and plugs. The end results are no more point maintenance and you get a nice hot spark at the plug. I did a rough measurement and found that the voltage at the plug went from about 12,000 to 30,000 volts. You can build it yourself or Last Chance Marina will build one for you. Installation takes about 5 minutes. (The coin in the picture is an American Quarter ....)
|A shocking topic - spark plug cables! - I was using a digital VOM to check the charging voltage of the generator when I discovered that the EMF radiation was so great from my solid core spark plug cables that it rendered the VOM useless when the engine was running. I went to the local auto supply and bought a set of Accel Spiral Wound spark plug cables. Low loss, low noise and now my VOM works.
|Fuses - gotta have 'em. Know where to put 'em? -
|On the water you still need ground -
|A scary story with a happy ending - This article was printed in the Fall 1997 issue of the Fourth Watch, the quarterly publication of the Adirondack Chapter of the Antique and Classic Boat Society. This article has been reprinted here with permission from the author, Scott Dorrer. Read it and heed!
|Stuff & Sources
|8 Volt DC Battery
|Exide or NAPA
All Contents © Copyright 1998
Last Chance Marina