Electrical and hardware updates for Sunset Chaser

My five-metre runabout Sunset Chaser has been undergoing an assortment of repairs this winter. Here's a brief overview of the wiring and hardware updates I've been doing on this boat, in the hopes of keeping her going for another decade or so.

Sunset Chaser is now starting her 11th season. She's logged just short of a thousand nautical miles on the water in that time, plus at least five times that distance being vibrated around on her trailer. A thousand miles is small potatoes to an ocean cruiser, which might knock off that much in a week, but it's quite a lot of hard use for a trailer-borne runabout on inland rivers and lakes. It's also worth noting that when I originally built and launched her, I was just starting high school and knew little to nothing about "proper" techniques for woodworking and fibreglassing. So it should come as no surprise that a 10-year refit would be in order.

Up first is the wiring. It's darn near impossible to put a reliable wiring system in a completely open boat, no matter how closely you follow ABYC guidelines. Water is going to get into places you don't want it to go. Once water gets into the switches and fuses and such, things start to corrode. Pretty soon, you have switches that don't quite make contact and circuits that randomly cut out every few seconds.

One approach is to keep everything dry, spend a fortune on the most corrosion-resistant marine grade parts available, zip-tie it all in place and hope it lasts 20 years. That's great for a boat that has dry places. But on an open runabout, even the best marine-grade switches and terminals will get wet and corrode. Since they'll have to be replaced in another 10 years anyway, I'm taking a slightly different approach here: Use cheaper parts where possible, but design for easy repair and replacement down the road.

Sunset Chaser's new switch panel

There's not much on the panel yet, but I've left room to add a remote tachometer, GPS mount and additional controls as needed. The underside of the panel is protected but easily accessible. Note the "drip loops" bent into the wires as they approach each terminal; this helps to keep any water that does get in from lingering where it would cause corrosion. You can also see the hefty brass negative bus bar, behind all the wiring- it's actually quite easy to reach, the perspective of this photo notwithstanding.

Underside of switch panel

I've used an automotive-style ATC fuse block here, instead of breakers, to keep costs down. It's just as safe and only marginally less convenient than fancy breakers, at one-fifth the cost; how often does a 5-metre runabout blow a fuse, anyway? (This one hasn't had a short or a blown fuse in ten years.)

I'm not a huge fan of the spade terminals you see above. They work, but it's possible for them to weaken their grip and vibrate loose over time. But that's what all the parts came with, so I can live with it- we'll just have to periodically check that no wires have worked loose. Just like we would with any other kind of terminal.

The battery ends of the main DC cables are shown below; the battery posts are different sizes and the terminals must fit accordingly. Note the heat shrink tubing protecting the crimps from water ingress. Given the choice between insulated terminals and non-insulated terminals supplemented with heat shrink, I'll choose the latter (even stripping the plastic sleeve off the normal ones, if necessary): you get a more secure crimp, the connection takes up less space, and it's better protected. This is adhesive-lined, double-wall 3:1 heat shrink, which costs about double what the usual 2:1 stuff goes for; the difference is that this is sturdy and water resistant, while the cheap stuff is just to stop you from getting zapped.

Battery terminal crimp fittings

I've also been fixing up some hardware. When Sunset Chaser got her Johnson 30 engine, we fabricated a steel bracket to help spread the load and reduce fatigue on the wood transom. That worked well, but water got in places where it shouldn't be. So I've bored out all the mounting holes and lined them with thickened epoxy to keep the water at bay, and to help reduce the stress concentrations at the eight 3/8" bolts. (It's still pretty filthy-looking, thanks to engine grease and a lot of deteriorating silicone-acrylic bedding compound that's about to be replaced with 3M 4200.)

Steel transom reinforcement

Epoxy reinforcement around motor mount bolt hole

The same epoxy reinforcement has been done at the bow eye, along with the addition of a hefty machined steel backing plate to replace the old stamped one (which had been bending too much under load, leading to stress concentrations and damaging the laminated stem.)

Bow eye backing plate

Finally, there was some hull damage to repair. A "permanent" dock turned out to be not so permanent after all; it shifted overnight during a storm, exposing a nasty deadhead underneath. Sunset Chaser pounded on that deadhead all night, and it wore through the outer protective layers and damaged the fibreglass skin. This exposed the plywood hull to water, so it had to be dried out before it could be repaired. Thickened epoxy, fibreglass and a wax paper cover to smooth it out produced an ugly, but strong and workable repair; with a bit of paint it'll be indistinguishable from the surrounding hull. I never bothered to fair her to a mirror finish in the first place; it doesn't make a shred of difference in performance (this area is out of the water at any speed above five knots) and at the time I was eager to get out on the water!

Repaired damage to fibreglass skin over plywood hull




Something I have been doing

Something I have been doing over the years, that you might find helpful: When making a splice or adding a fitting on the end, I will apply a layer of silicone sealant to the soldered or crimped connection before sliding the heat shrink tubing over and shrinking it. If the silicone squeezes out a little at the ends, that is just fine. In the end, I have an electrically sound, permanently sealed / very water tight connection.

Also, could those blade connections benefit from a layer of dielectric grease to keep them corrosion free or do you think it would wash off too fast to really do any good.?

Add new comment