Amateur Boat Builders and Marine Electrical Wiring


As a designer and builder as well as a marine electronics/electrical technician I have seen boats become in some instances large collections of electrical ‘things’ along with large battery banks to feed these electrical goodies. If you are building your own boat and it will have electrical equipment on board beyond the engine starter and maybe navigation lights, read on.
Depending on the size of the boat and what ‘things’ you want or need, having a professional help you or do the planning and installation might be a good idea BUT in my opinion there is a level of complexity an amateur can take on with the right knowledge and information that does not require going to school. What is this level of complexity? First keep your systems to a minimum. You will probably need navigation lights, maybe some cabin or utility lights. You may want a fishfinder or depth sounder, possibly a VHF radio, maybe a small chartplotter/GPS. You will need or should have at least one bilge pump, a horn, maybe a sound system. This is a reasonable list though not complete that could be handled by an amateur builder. What you don’t want to tackle for your first major project, dual 12/24 volt battery systems, lithium batteries and you might want to think seriously about having AC power stuff on board utilizing shorepower. AC power requires a lot of care. The advantage of doing the work yourself is twofold. First you save labor money and secondly and more importantly, you understand your electrical system and will be able to add to your system and repair your system, particularly if you are on the water.  I will be posting a procedure for planning your electrical project along with postings to develope the knowledge needed to be successful at doing your own project. After you build your boat, planning and installing your own electrical system is a real feather in your cap.


Overhauling A Jon Boat Part 2

As mentioned in the post on November 25th, we were getting ready to tackle repairing the after section of the jon boat because of severe pitting corrosion that ate through the hull bottom due to florists foam put in place of regular flotation foam during a previous repair.


Port side. Holes with rivets are in the black circles.


Starboard side. Holes with rivets are in the black circles

What we did first was to clean up the aluminum in the areas of the pitting with a wire brush and determined where the pitting created holes in the hull and where it only did mild surface damage. We identified holes on both sides of the hull and also determined the holes were the only serious damage. Some of the other surface damaged by pitting were shallow. We then applied Rustoleum Self Etching primer for the undercoat  then painted the surfaces with a Rustoleum camouflage color. After drying we drilled out the pits with 1/8″ drill. Luckily none of the pits themselves  were larger than 1/8″. We then applied a 2-3mm coating of 3M 5200 all over the areas. (in the photos it is the orange color, the camera flash distorted the actual color) using a plastic spreader. This layer of 5200 smoothed the hull surface by filling in the eroded areas.  We then inserted rivets in all of the holes while the 5200 was still wet. The 5200 seals the rivets, making sure the rivet will not leak over time. If the pitting areas were deeper or more holes found we might have placed an aluminum plate over the area using the 5200 as an adhesive. As it was we feel the rivet solution was the best for this repair.

The next repair is the transom. The plywood stiffener was rotted and needed to be replaced. Stay tuned.

The Browns Ferry Vessel

After we moved to Georgetown, South Carolina, I joined the South Carolina Maritime Museum. The first project I got involved in was to develop model plans for a two masted freighter that was recovered from the Black River in Browns Ferry, South Carolina. This boat has been dated by nautical archaeologists, to have been built in the early 1700’s. The first research model was built in the mid 1970’s by Richard Steffey.



Steffey’s Model. Built at 1/10th scale


This Browns Ferry Vessel was found in 1971 by divers exploring the Black River and at that time was the oldest boat of its kind found in the United States.  A nautical archaeology professor, Richard Steffey from Texas A&M University was the first Nautical archaeologist to examine the recovered vessel.  At this point it was called the “Browns Ferry Vessel” because that is the location where it was found. Subsequent research could not find any record or history of the vessel so the name stuck. It is deceiving because it makes you think it was a ferry boat, which were plentiful in the area back in the 1700’s. But the Browns Ferry vessel was a freighter and as a matter of fact when it was found it still had its cargo of 10,000 building brick. Brick making was a side product of many Southern plantations and the Browns Ferry Vessel (BFV  as it is also referred as) was carrying a load of bricks when it sank sometime in the mid 1700’s, sinking dated by artifacts found on the vessel. The vessel is 50 feet long and 14 feet wide with a draft of 3 feet.



The BFV coming out of the PEG tank.


The vessel was fully recovered in the late 1970’s and sunk in a preservation tank for 9 years. The tank was filled with polyethylene glycol  (PEG),a wood preservative which soaks in the wood and replaces all traces of water with PEG. The wood can now stay in the air without rotting. The BFV was removed from the PEG tank in the late 1980’s and eventually wound up in a museum in Georgetown, South Carolina. The museum that holds the BFV now, is named the “Rice Museum”. It was the only museum in Georgetown at the time that could host the BFV. The roof of the Rice museum was removed and the BFV was lowered into the top floor and the roof then replaced. The boat and the first model are still in the Rice museum.

My involvement in the BFV through the South Carolina Maritime Museum was to build a model of the BFV for our museum. When I researched all of the literature on the vessel to design the plans, I come across the the debate about the stern of the BFV. Steffey and others felt that the BFV was a “double ender” meaning the bow and stern were pointed. Others disagreed, they thought the transom was flat. As Steffey was the lead investigator, his model was built as a double ender in the mid 1970’s. When the BFV came out of the PEG tank another Nautical archaeologist (Dr. Frederick Hocker, a former student of Steffey’s) thoroughly examined the vessel and did determine from planking runs that the vessel had  a flat transom. Hocker shared his findings with Steffey who agreed with Hocker that the BFV did indeed have a flat transom.  A few research models were built by Hocker to check the plausibility of the planking and flat transom. None of these were ever finished to a complete display model until I designed the plans for the South Carolina Maritime Museums  model. In consultation with Dr. Hocker I developed the plan set for a display model with the flat transom. The following photos are the final result.





As I am not a well experienced model builder,  the model was constructed by another museum member, Bill Brady who has been building model ships for over 30 years. I generated 30 drawings of the BFV and all of its structures based on literature research as well as having the remains down the street at my disposal. I modeled this vessel using Rhino 3D, a 3 dimensional design program that I use in Yacht design. The drawings I created could be used to build a full scale replica of the BFV if some one wanted to and had the money. The drawings were scaled down to the model size and between Bill and I, the model was built and is now on display at the South Carolina Maritime Museum in Georgetown, South Carolina.  You can see that the two models do not look much alike. This is due to the fact that Steffey had very little time to examine the BFV because of the need to get it in the PEG tank. Hocker was able to spend plenty of time examining the remains and could study the BFV in fine detail. So based on his research the vessel is a little different in structure than what Steffey originally thought.This model is 1/10th scale like the original. At this scale, the model is 5 feet long, 16 inches wide, and 4 1/2 feet tall. This was a very satisfying project and I am looking forward to a couple of similar projects in the near future. Stay tuned.

The finished model on display


Part 2 – Sizing Marine Wire For Your Boat Project

If you read the article mentioned in the post on “Marine Wire” you are ready to read the next article. This article is on sizing the wire for your boat project. Determining the right wire size is CRITICAL to your boats safety in terms of fire safety. Overloaded wire will almost certainly cause a fire on your boat, a situation none of us want. In addition to fire safety, the proper wire size  does affect the operation of most of your electrical equipment on board your boat. Read the article to find out more  by clicking this link.

Sizing Marine Wire

Designing a Boat Part 1 Initial Considerations

The first step in designing a boat is to have some idea as to what you are intending to do with the boat. This applies to many  other situations including buying a boat, building your own boat or buying a kit boat. It pays to write down your answers to these questions to help you stay focused on  what you want because you may forget why you chose a characteristic and seeing it in print will help you keep track of your thought process.

Questions to consider are:

  1.  What kind of waters are you going to use your boat on. Examples, ocean, lake, river, protected bays. When considering these waters you must know what kind of water surface, rough, smooth, fast currents. While ocean water will have all of the above characteristics, lakes can get rough, rivers can look smooth but have fast moving currents, bays can be rough and have days of being calm depending on the tides. Depth of waters you will work in is also an important consideration. Shallow waters mean a flat bottom or others hallow draft type of boat that does not set deep in the water. The bottom line: KNOW YOUR WATERS. This will primarily determine your hull shape under the water as well as topsides. A designer can help or one of the many Forums on the internet.
  2. Powering. Sail, power, oar or other? Obvious, but this must be thought of in unison with the waters you are using the proposed boat on, and do you want a relaxing ride or want to move like a rocket.
  3. How big a boat do you want? Things to consider here are: number of people you are going to take out, your experience level at handling certain size boats, what kind of creature comforts you desire (day boat, or overnighter with some protected sleeping space), actual use of the boat (fishing, cruising, etc.) , and the biggy, HOW MUCH ARE YOU ABLE TO SPEND. Also  bear in mind that boats over 30 feet usually can’t be hauled on a simple trailer, they need to be professionally hauled so you have to plan on getting marina or mooring space and plan on hauling twice a year. If this does not appeal then a trailerable boat is the answer. This will keep the maximum length at 30 to 32 feet.                            This question is loaded and requires much thought because the success of your experience with this boat is all in the answers to this question. There will be plenty of compromises to be made unless you can go over 100 feet in hull size. A serious thought, just because you have the money don’t go after a boat that is bigger than you can safely handle, an error made to often. You will be dangerous and may not use your boat. That translates into a waste of time and money. One must always walk before running in the boat world. Your life and other’s may be at stake.
  4. What building material do you want? Now we are getting a little technical. If you are building a boat yourself, plywood would be the logical choice. Many kits and plans are out there for plywood boats. Plywood  using today’s techniques works out real well, it is rugged and easy to work with and almost as easy to maintain as fiberglass. If you know how to weld and can work with steel, then steel might be a way to go. Steel is rugged but it (in my opinion) keeps you away from boats in the under 30 foot category due to weight of hull. Also coating the steel to control corrosion is a must and ongoing process until the end of the boats life. Aluminum is a great material for boats. It is light weight, strong and practically corrosion resistant. But you will need a builder who builds in aluminum unless you can weld aluminum. Rivets can be used but eventually they can develop leaks. The last choice is fiberglass (FRP or GRP).  FRP is okay if someone else is going to build your boat. Building a single hull in fiberglass is expensive and time consuming. There are no kits out there to my knowledge so you will be buying plans or having plans designed for you. If you want to do it yourself then be prepared to learn a lot about fiberglass chemistry and technique. There are other wood options out there such as conventional wood planking and a technique using wood strips called COLD-MOLDING. These are professional techniques. I will discuss these further in a future post. Of course a professional designer knows all of this and may be your best starting place.  You need some of this knowledge even if you are going to buy a kit or attempt a simple design yourself.

There may be other questions to consider, but these are the major ones you have to ask yourself.  As you consider these questions you need to be aware that there will be compromises that will have to be made, particularly if money is a major consideration. While writing these answers down think of other things that may pop into your mind. Write them down and think hard about them.

For this example boat, these are the answers to the questions above:

  1. The waters are bay and salt marshes. Which means the waters are protected… no real rough water, no river currents. Water could be real shallow.
  2. Propulsion will be power using a small outboard with a  trolling motor.
  3. Boat will be used for fishing, duck hunting and casual cruising the local bays and marshes. No more than four people on board. This will be a day boat with a small cuddy cabin. The length will be around 18 to 19 feet.
  4. The boat will be plywood as it is a home build project. The plans will be designed for plywood ( such surfaces are called developed surfaces) so there are no  curved surfaces that plywood can’t conform to.

With these questions answered we can start thinking about the hullform and other major structures to match your needs. Once the design begins you may have to visit your requirements repeatedly to help refine the ultimate hullform and structure of your boat. As mentioned earlier the more thoroughly you think about these questions and possibly come up with others to think about, the more successful your boat project will be as well as your experience using your boat.

Part 2 of this series will cover the initial design of the hull.