Solar Panel Install on Estrellita 5.10b

Livia and Carol have described the installation of their solar panels on s/v Estrellita 5.10b. Nice machining and a very professional job.  And I like how they planned ahead for the need to remove the panels quickly in an emergency.

Back when we installed our solar panels I had taken these photos so I could talk about the install. I had a pretty complicated time figuring out how to get everything to fit on top of the bimini. I'm not sure exactly why because in hindsight it seems so simple. Hopefully some of these visuals might help someone else work out their installation.

We mounted aluminum barstock on the back of the frame to give us more options for mounting and also to act as a stiffener/brace to the existing aluminum frame.


We fastened the aluminum barstock to the frame with spacers I cut from starboard and stainless u-bolts with wing nuts. The wing nuts and u-bolts are intended to simply the removal process in an emergency because they can be removed by hand without tools.


We used sealing ring terminals on the ends of the wire which were fit through the gasket provided by the manufacturers (2 Sharp 80W and 1 Kyocera 85W).


This is what the inside of the built in junction box looked like. We wired the panels in parallel and this panel has the wires from the preceding panel as well as wires going out to either the next panel or the MPPT controller.



The end wires come through the cockpit combing and down under our aft berth to our Blue Sky MPPT controller like this.


An overview of how the panels were working during this past summer is here.

And by the way, you can now find solar panels on eBay for less than $2/watt...

Dutching in

On a boat of any age, there will be places where the woodwork has been damaged.  In Eolian's cockpit, the coaming cover had holes drilled to accommodate pegs in the cushioned seat backs (to keep the seat backs in place).  Because of the design, it was easy to apply substantial leverage on the pegs and holes when lifting up the seat backs.  Not surprisingly then, there were places where the pegs broke out the edge of the teak cover board.

What to do?  We'll pick just one of the breaks in Eolian's coaming cap to follow - one in which the Previous Owner had sanded and finished the split-out surface in an attempt to disguise the damage:

Piece broken out, and then refinished!

We will be gluing in a new piece of wood, in a process called "dutching in".  Sorry, I don't know where this name came from.  In order to do this and have a thin glue seam, the contour of the area to be repaired must match the contour of the piece which will be ductched in.  This is easiest by far if we are matching two flat surfaces.  So, using whatever tools are appropriate for your repair (I used a hammer and a chisel here), clean up the surface of the area to be repaired, creating a place for the filler piece to nestle into.  Choose your filler piece carefully - it should have grain and color that are a good match for the area being repaired.

Next, using epoxy (I used 30-minute stuff here), and whatever clamps are required to hold things together until the epoxy goes off, glue in the filler piece:

Repair piece is epoxied into place

Once the epoxy has hardened, use whatever tools are required to trim away the extra wood.  In this example case, I again used a chisel, but a small saw could have worked too, or perhaps a Dremel tool.  Then sand the repair area.  You'll see that in the example, I did not pay too much attention to the actual peg hole because I was going to re-drill it anyway to take a bronze bushing:

Trimmed and sanded

Finished; bushing installed

It's really not hard to do. Just don't be in too big a hurry... spend the time to make the patch as invisible as possible.

Look closely at any classic wooden boat - you will undoubtedly find dutched in areas...  now that you know what you are looking for.

In praise of DIY

I have long been an adherent of the DIY philosophy - you might have guessed that, given the purpose of this blog.  Most boaters are DIY'ers by nature - thus the popularity of this site!   Aside from the obvious cost savings, when you successfully complete a project yourself, there is a wonderful feeling of satisfaction, of competence.

And in the boating world, DIY makes even more sense.  There are those who proclaim that "the only tool I need is a Visa card."  That certainly works, if your boat never leaves the dock.  But when you are at sea, that credit card is not very useful - except, perhaps, if you are in need of a thin plastic shim.

Over at Boat Bits, Robert has posted an essay on this subject that I encourage you to read.

Safety warning: Sealed lead-acid batteries

Scott over at DowneasterYachts.com has posted a graphic warning concerning sealed lead-acid batteries.  Because we feel that safety information should be broadcast as widely as possible, we will repeat it in full here on Small Boat Projects.  Please do not take this as a condemnation of this type of battery.  Instead, this is a reminder that there is no ideal type of battery - all choices are compromises.



Here's Scott:

David Gill, new owner of Tondelayo and new member here ran into an interesting situation that is relevant to us here.  As a matter of fact I have 6 AGM batterys on Valkyr.  I like them because you can’t spill acid out of them.  I have had bad problems on a prior boat with that.

However the description here and the photos David provided are very sobering.  I have had 3 AGM batteries in the past that have swollen in a very limited way and went bad.  We had them replaced.  I have had this happen to a couple of west marines SeaVolt AGM group 27 and 31 batteries as well as one of the optima blue top spiral AGM batteries just in the last month.  So this is a very reasonable heads up.  Thank you David for writing this up, and submitting it with the pictures.

Hi Scott.

Here’s a bit of information that may be relevant to anyone using Sealed 12v batteries.  I don’t use them on Tondelayo but anyone who does wouldn’t want this to happen while at sea.

At 0848 hrs on 12 July 2010, pumper 402 Nelson Bay attended a caravan park in Nelson Bay.  On arrival they found a 12V sealed caravan battery (also called Valve Regulated Lead Acid or VRLA battery) with its sides and top markedly bulging.



Park staff had removed the battery from inside a caravan to a grassed area.

The BA team was to cool the battery with spray from a line of 38 mm hose from behind substantial cover. However, the battery slowly continued to expand. Temperature readings taken with a TIC registered 49 ºC.

As it appeared the battery could explode, a hot zone of 30 m and a 50 m exclusion zone were established. A second pumper and hazmat were called to assist.

Accessing the internet from 260 Hazmat’s laptop, a VRLA battery distributor was contacted. They advised to cool with water for the next 24 hours and then disposed of at a regular council battery collection point.

Sustained cooling from substantial cover eventually reduced the battery’s temperature to 26 ºC. After being deemed safe, it was immersed in water and placed in an isolated area of the council waste disposal facility at Port Stephens. The battery’s condition was monitored by council staff and the NSWFB was contacted when the casing broke open two weeks later.

Concerned about the impact that a battery explosion would have in the confined living area of a caravan, SO Kwan submitted an observation to the Lessons Learned Centre. We found that:

• VRLA batteries are used in a variety of applications. Different types can deliver short duration – high energy output (for starting combustion engines) or release energy more slowly (as power supply backup for telecommunications equipment, etc).
• They do not need topping up with water. Oxygen evolved at the positive plates recombines with the hydrogen ready to evolve on the negative plates, creating water and preventing water loss.
• Several conditions can cause the battery to heat up, such as high ambient temperature, poor ventilation, incompatible charging equipment, charger malfunction and battery cell failure.
• Generally, gas is not produced during charging. However, if a battery is overcharged due to charger malfunction or battery failure, gas pressure can build within the battery. A pressure relief valve is designed to release the excess hydrogen and oxygen.

At the Nelson Bay caravan park, it appears that either the relief valve failed or the heat and gas generated during charging exceeded the valve's capacity. The plastic case softened with the increased temperature and the higher pressure inside caused it to expand. As it cooled, the plastic case became hard and brittle, and eventually broke.

Firefighters are asked to contact FIRU if they encounter expanded VRLA batteries. This will help to research the frequency of this and whether there is a problem with charging units or the batteries themselves.


Regards,

Dave Gill

Mobile: 0488 285 286

Email: davegill@southernphone.com.au




PDF Download

Sobering.  I wonder if our Australian readers can shed any additional light on this incident?

Shore power issues

If In Doubt, Change It Out

If your shore power inlet looks like this, you know you need to change it.  That pin got hot because of a poor connection, which could have been in one of three places:

1. Where the wire is connected to the pin, at the back of the inlet fitting.
2. Where the plug contact makes contact with the pin
3. A poor connection between the wire and the contact in the mating plug

In any case, now you must change out the shore power inlet fitting.  But you should also change out the plug which mates with it.  Here's why:  In order to ensure a good connection, the contacts inside the plug spring apart as the pin from the shore power inlet is inserted.  This spring action results from the shape of the contact, the material, and its temper.  If the pin has been overheated, its mating contact likely has too, and probably has lost its temper.  Therefore, if you only change out the shore power inlet, the connectors in the mating plug, now having lost their springiness, will make a poor connection with the pins in the shore power inlet (see #2, above).  The next time the boat draws a big load, it is likely that the plug will heat up, destroying both itself and the newly installed shore power inlet, and possibly even the entire boat.

Be a Loner - Get Isolated

There are three wires in that connector.  Traditionally, these are called the hot, the neutral (these two carry the power) and the ground.  Strictly speaking, the ground is unnecessary - it is there as a safety precaution.  If, for example, one of your appliances should develop an  internal short (say, the casing of the heating element in your water heater cracks, and water seeps in, connecting the actual heating element and the casing, and in turn the water, and the water heater tank, etc.), this ground lead, which is connected to the external parts of everything electrical on your boat, ensures that you are at the same potential as the cases, knobs, etc. and therefore do not receive a shock.  If substantial current flows thru the short, a breaker will trip - which is the desired action.

On shore, "ground" is established by driving a metal rod literally into the ground (your house ground will also be connected to your water supply, which is even more metal in the ground).  On the water, what gets used as "ground"?  This is not as easy to explain.  The obvious answer is: the water.  But on a boat, there is something else going on.  Much of the submerged external metal on your boat will be protected from galvanic corrosion by attached zincs which, being higher in the electromotive series, will corrode to protect that submerged metal.  But if we connect the boat AC ground to the water, then we are at great risk of electrolytically dissolving that external metal!  More on this in a moment.  Selfishly, look at it this way.  If your zinc-protected external metal is attached to your neighbor's external metal, then your zinc will be protecting both your submerged metal and his.  If both boats have their green ground wire connected directly to the boat ground, then your zinc will protect his metal.  But it is much worse than this...  your zinc will also be protecting all the marina's submerged metal as well, starting with your dock.  So how to provide the safety protection that a ground delivers to someone onboard, without truly sacrificing your zinc?

There are two ways.  First is the galvanic isolator.  This device gets inserted into your ground wire right after it comes aboard.  You just cut the wire, and attach the two ends to the two terminals you see there.  Thru electronic magic involving diodes, ground currents are carried but electrolytic leakage is barred.  This is the lower cost solution.

Unfortunately, the galvanic isolator is not a perfect solution.  Chief among its flaws is that it can silently fail.  That is, it can go open circuit, in which case your first notification would be when you got that shock we were talking about earlier.   A better but more costly answer is an isolation transformer.  This device literally isolates shore power from the boat, with the only connection being via a magnetic field.  Perfect.  But they are heavy, and expensive.  Like the man at the carnival says, "You pays your money, and you takes your chances."  But the only true losers at this game are those who do not play.  You need one of these devices.

Belt And Suspenders

Adding a second layer of protection, Ground Fault Interrupters are now, like in houses, required equipment on all circuits on a boat near water:  the galley and the heads.  But realistically speaking, any circuit on a boat is near water.  They should all be GFI protected.  This one is easy to do.  How many AC outlet circuits do you have on board?  One?  Two?  Three?  Well then you just need to go to Home Depot and buy one/two/three GFI outlets.  Locate the first outlet on each breaker (it'll probably be the closest one...), and replace the standard outlet with the GFI outlet.  All the downstream outlets on that circuit are now protected (they even include little stickers in the GFI packaging that you can affix to the downstream outlet covers to attest to this).  This would certainly qualify as a small boat project.

In Should Equal Out

When a large Krogan here on G Dock was hauled for a sales survey, an expensive problem became immediately apparent: the 3" thick full length stainless steel keel shoe was completely eaten away by electrolysis. Lawsuits flew. In the end, the marina staff checked each boat on the dock for leakage, by simply applying a clamp-on ammeter over the shore power cord. If the amount of current being supplied to the boat was the same as that returning down the neutral wire, the ammeter would read zero. Surprisingly several boats were found to be leaking tens of amps into the water. Remember that cracked water heater element casing from above? As long as the total current drawn did not exceed the breaker's trip rating, that extra current was leaking out from the boat, energizing everything in the vicinity.

Clamp on ammeters do not need to be expensive.  So here's another small boat project:  get one, and check your boat's electrical system from time to time.  Check your neighbor's too!  Heating elements in water heaters and coffee pots crack long before they fail completely, motor windings short to their casings thru conductive dust from the brushes, insulation on wires chafes.  An annual check is a good thing.

Final Words

Shore power is a wonderful boon to the boater, but it is not as simple as just plugging in the cord.  But then, nothing on a boat is.

Sticky question

Polyvinyl chloride (PVC) is a brittle plastic.  (In your mind's eye, take a vinyl record and smack it on the edge of a table - it shattered, didn't it?)

PVC can be made into an entirely different sort of material by blending it with an "inert" oil as it is molded - this gives you the flexible PVC you know for fenders, lifelines, and wire insulation.

Unfortunately, the oil doesn't stay put - in sunlight, it migrates to the surface of the PVC and then it oxidizes and polymerizes into a sticky mess.

So here's my question to all of you reading:

What method have you found best for ridding fenders and shore power cords of the sticky polymerized plasticizers in PVC?

Come on now, don't be shy - I know there are a lot of you reading this - tell us how you deal with this problem!

Bubble wrap

The under sides of Eolian's floorboards were apparently originally covered with some of that multi-layer sound-deadening material.  You know, the stuff with an aluminum backing layer, some foam, a thin lead sheet, and finally more foam.  This is pretty good stuff for absorbing sound, and putting it on the undersides of the floorboards would stop a lot of the engine noise from entering the cabin.

But.  Over time, foam disintegrates.  By the time we got her, Eolian's floorboards had only the aluminum backing material left almost everywhere.  And it was dull and kind of corroded.

So I covered the aluminum with aluminized bubble wrap (please ignore the plastic drop cloth behind the raised floorboard - that was a different project).  Because the metal is encapsulated in the plastic, it won't corrode.  Tho the bubble wrap does nothing for sound deadening, it sure looks a lot better!

Hardening the corner

On the under side of Eolian's bowsprit, where one fluke of our Bruce anchor rests when the anchor is hauled home, the corner had taken somewhat of a beating from contact with the fluke.  I spent an hour or so in the dinghy with a hammer and a chisel, relieving the area where the contact was being made, about 1/2" deep.  After painting the bare wood, I installed a 6" stainless rubstrake.

This worked well enough that when I constructed the new bowsprit, I copied the design.

How do you spot a *real* cruiser?

Mike, over at Zero to Cruising, tells us...

How can you tell a “real” cruiser from a recreational boater? You can’t tell by the fancy burgees (flags) in their boat’s rigging. Nor can you tell by the anchor on their bow (although a nice big one is a pretty good sign). We’ve determined that the best way to tell if someone is a (long distance) cruiser is by the fuel and water jerry cans carried on their deck. I remember hearing from someone that certain charter operations would actually tell their customers to find boats with jerry cans on deck and to anchor nearby them, assuming that they would know what they are doing!

Before anyone pipes up and says something (John!), yes, we do have a sailboat, but we have (sadly) learned that relying solely upon the wind for propulsion could make for some very long days. Yesterday would have been a great example of this! Our boat carries 27 gallons of gasoline in its main tank and burns approximately 1 gallon per hour when running on 1 engine. Although we won’t be making any huge runs until we get to the Mona Passage between the Dominican Republic and Puerto Rico, we are getting ourselves prepared.

The typical method for carrying jerry cans on deck is to string a board between two stanchions and lash the cans to it. There is only one really appropriate spot on our boat for this and the span between the stanchions there is about 6 feet. Because I think that is a fairly big span and I wanted something strong enough to support the weight of 3 cans, we decided to go with 2×6s, but what material to use? After debating for quite some time and counting our pennies, we decided to go with cedar. We purchased one 14 foot plank and had it cut in half, rounded the corners on each piece and sanded them smooth. I purchased some U-bolts from the hardware store to attach the boards to the stanchions but before doing so, was chastised by our friend Kirk for cheaping-out and not buying stainless steel ones. So, I guess it’s back to the chandlery then.

Once the cans (4 fuel and 2 water) are all ready to be attached, the final thing we need to do is to protect them from the sun. We have heard that the UV damage can be serious so Rebecca plans to sew a nice Sunbrella cover for each of them. We’ll post some more pics when we get it all done and looking pretty.






Checking the placement for the cans. We’ll carry 2 gas and 1 water can on each side.

Fortunately our friend Kirk has a good selection of power tools to speed up the job.

And I guess it should be added that we have two 5-gallon jerry cans of diesel and a 2.5 gallon can of outboard gas tied to our stern rail on Eolian.  But no board.  Is that close enough?

How to: wire and connections

Boat projects frequently involve electrical wiring.  And in my experience, it is owner-installed wiring that poses the greatest risk on many boats (it certainly was on Eolian).  So, how can an electrical project be done without putting the boat at risk?  Last time, we talked about breakers.  Today let's focus on wire and connections.

First, the wire.  Although houses are wired with solid wire, solid wire should never be used on a boat, not even for the 110V circuits.  Houses don't move (well, except in California).  Boats do - they sway, they pound, and they vibrate.  Solid wire will eventually fatigue and break, probably inside the insulation where the break will be hidden.  The ends will still be in contact, and will spark, generating heat, and possibly a fire.  You should always use marine-rated stranded wire.  This wire will be made of strands that are finer than regular stranded wire, so that it is more flexible and resistant to fatigue.  Modern marine-rated wire will have strands which are individually tinned (coated with a thin layer of metallic tin)  to hold back corrosion.  It's easy to tell if the wire is tinned - it looks silvery instead of coppery.

Next: support.  Now that we have the right wire, we still need to minimize the effects of boat movement and vibration on it.  In order to prevent fatigue breaks at the supports, the wire should be supported frequently along its length.  The supports should be padded if they are metal (which should be stainless steel)- no padding is necessary if they are nylon or other plastic.  Where the wire penetrates bulkheads or other surfaces, the edges of the holes need to be padded to prevent chafing of the insulation.

And finally:  the part of a circuit that is most likely to be the cause of a fire is not the wire itself, but the connections.  We are using stranded wire, and stranded wire does not do well when clamped under a screw - the strands tend to separate and squeeze out, making a risky connection.  Therefore on boats, the ends of the wires will get crimped-on connectors, which can be safely clamped under a screw.  With a crimp-on connector, the strands are trapped and cannot escape (there are some kinds of equipment which use a connector that, when a screw is tightened, traps the wire between two pieces of copper - these can be safely used with stranded wire).

Crimp-on connectors come sized (and color-coded) for specific sizes of wire - this is both because the hole into which the wire is inserted for crimping must fit the wire, but also because the crimp-on connector is itself part of the circuit, and must be capable of carrying the same current load as the wire.  Ring terminals are the most secure, but in some places they may not work (standard 110V outlets, for example - these have trapped screws).  Where rings won't work, flanged spade connectors can be used.

Some advocate soldering crimp connectors - it makes a secure electrical and mechanical connection even more secure.  But when you solder the connector, solder wicks up the wire for a little distance from the connector, making a hard spot where fatigue can set in.  I don't solder my connections.  If I have any doubt at all about whether corrosion could set in, I use adhesive-lined shrink connectors.  Oh, and get a good crimping tool.  Those ones stamped out of sheet metal are not adequate for any but the smallest connectors.

Look at some commercial crimps.  You will see that the edges of the metal are folded in, making a profile that looks like a capital 'B', laid on its side.  Yours should look like this too.  Yes, it does matter which way the connector is positioned in the crimping tool.  Practice until you are making good crimps.

In an ideal world, I'd say that there should never be more than one connector under a screw.  In the real world, well it is likely to happen.  If there are multiple terminals under a screw, it is important to pay attention to the order in which they are stacked.  Take the starter terminal on the engine, for example.  Quite often, the primary connection for 12V to the engine (dashboard instrument power, alternator sense, etc.) will be made to the same terminal that carries battery power to the starter.  Under no circumstances should the small-wire terminal be positioned between the battery cable terminal and the starter body - that would cause the 100+ amps the starter draws (Eolian's draws 200 amps) to pass thru the small-wire terminal - way more than it is rated for.  Where both of these connections must be made at the starter terminal, the best practice would be to position the battery terminal in place, screw down the nut tightly, and then position the small-wire terminal and add a second nut.  Be sure that all connections are clean, metal-to-metal contact.

When you are all done, check your work.  No connection should ever get hot to the touch (warm perhaps, but not hot).  Pay particular attention to the ones carrying high current.  Check them under sustained full load (if it is a 110V circuit, please de-energize it before touching it!).

Next time:  Shore power issues.

12V hookah?

Alright - all you project-oriented sailors out there, listen up.

I would like to know if anybody has built their own 12V-powered hookah rig for doing underwater maintenance on the boat.  I'm not talking about buying a Brownie or something, but rather using one of those ubiquitous 12V oil-less compressors... 

We're not talking about a lot of pressure here.  I am not contemplating real diving with it - I am just looking for something so that I wouldn't have to hold my breath while I scrape the prop.  At 0.5 psi per foot of depth, I'd think that 10-15 psi at the mouthpiece would be more than enough, if there was adequate flow.

So, who's already done it?

How to: choose a breaker

Boat projects frequently involve electrical wiring.  And in my experience, it is owner-installed wiring that poses the greatest risk on many boats (it certainly was on Eolian).  So, how can an electrical project be done without putting the boat at risk?  Although it's all connected (bad pun acknowledged), let's start today with breakers.

A circuit breaker is placed in a circuit to open that circuit if too much electrical current flows.  So, how does one choose a breaker?  And what does "too much current" mean?

The appliance and equipment manufacturers will often suggest or even demand that a certain size breaker be used to serve their equipment.  But this kind of thinking can lead to error.

You will not go wrong if you think about it this way:

The breaker protects the wire.

Not the equipment.  The breaker should always be sized to prevent the wire from carrying more current than it should.

Every wire which is carrying electrical current is a heater, according to the formula:

Heat = Amps² x resistance (in Ohms)

In a confined space (such as in a wire bundle or inside an insulated wall) this heat can build up to dangerous levels.

One might think that a house, with its 110/220V wiring would be the greater risk.  Not so.  On a boat, where many circuits are 12V, the currents can easily be many multiples of those found in household wiring.  Voltage does not appear in the formula - it is all about the current.  And in that formula, you will notice that the current term is squared - meaning that tripling the current makes 9 times as much heat.

The ABYC makes these recommendations for wire current carrying capacity:

AWG	Ampacity
	Outside Engine Space	Inside Engine Space
18	20	17
16	25	21
14	35	30
12	45	38
10	60	51
8	80	68
6	120	102
4	160	130
2	210	178
1	245	208
1/0	285	242
2/0	330	280
3/0	385	327
4/0	445	378

I think that these recommendations should be taken as the absolute extreme maximum current carrying capacity of a wire.  I prefer to size breakers according to the National Electric Code (which governs virtually all shore-side wiring, including that in your house).  The NEC says this:

AWG	Ampacity
14	15
12	20
10	30
8	40
6	50
4	60
2	125
1	150
1/0	175
2/0	200
3/0	225

It's always OK to have a breaker sized smaller than the current carrying capacity of the wire.

So what's a boat owner to do, when wiring in that brand new shiny 12V toaster?  The manufacturer's brochure says to use a 30 amp breaker. So install that 30 amp breaker at the panel, and then hook up the toaster using 10 gauge wire, because a 30 amp breaker will adequately protect 10 gauge wire.

How about that new GPS?  It comes with an 18 gauge pigtail with an in-line fuse.  Suppose you already have a 15 amp breaker on your panel labeled "Instruments", feeding a 14 gauge wire that leads to a terminal strip where a bunch of other instruments are attached.  You can attach the GPS to that terminal strip, confident in the fact that even if all the instruments should suddenly go berserk and draw more than 15 amps, the breaker will still protect the 14 gauge feed wire. 

If the GPS does not have an in-line fuse in the pigtail, install one.  A short in the pigtail wiring could draw as much as the power feed to the terminal strip allows - 15 amps in this case. Despite what the ABYC says, that 18 gauge pigtail will be smoking if it is handling 15 amps.   In fact, you should think of that terminal strip as a branch power panel, with each attached circuit protected by its own fuse, sized appropriately for its wire size.

Please note that any wire between a power source and a breaker or fuse is unprotected.  If something should happen to cause a short in this section of wire, the breaker will not see it.  Always install breakers or fuses as close to the power source as possible.

Next time:  Wire and connections

Those ubiquitous bags

Mike and Rebecca on s/v Zero To Cruising have found a noble use for those reusable grocery bags that seem to accumulate everywhere...

Some mention was made before about reusable grocery bags. We use them all over the boat for storage becuase they are both strong and flexible, fitting nicely into odd spaces on the boat. This one has various plumbing fittings and supplies. Each bag is labeled with a colored tag so that we can easily tell what is in them.

Now, if I can convince Jane to liberate a few of them for me...