Almost-A-SCAMP Progress Report #3-3F . . . .

[Charles Brennan]

Couldn't really start on the Bimini top modifications, until after the paint dried on some coaming changes I'd made, for the tiller pilot.
Figured I'd do a little Proud Work    and make a streamer for the yard peak, while I was waiting.
Got some rip-stop nylon and decided to have at it.
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Well  . . . . . .  THAT was a Major Fail.      WOW!!    Did I make a BUNCHA mistakes!!   
I put on some basting tape, to hold the folded seams together and the tape promptly gummed up the needle    and kept breaking off the thread. 
Quickly followed by a rats nest of stitches resembling a fuzzy caterpillar, from incorrect thread tension. 
And that fabric was wayyyyyy too light and thin, for a heavy duty sailmaker-type sewing machine. Especially on a size 20 needle, which was far too big.
Discovered after several You-Tube videos, that I needed much smaller needles and much finer thread.  (What??    Thread has gauges!?!?    Who knew!?!?) 
Yup. Needed a smaller machine. Like  . . . . .  my wife's sewing machine. 
No, I didn't "borrow" her machine; I didn't make it to over 51½ years of marriage, by being dumb in the Husband Department. 

I enlisted her help and ended up with this:
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She did a bang-up job and far better (and faster!) than I would have managed, but at least, I DID get the grommets on, myself!! 
 
The whole thing laid out, so I could tie a line on the grommets.
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Green streamer?!? 
Oh, look!    An Irish Pennant!!! 
(Sorry!!    Couldn't resist!!) 

(Not sorry.)

Time to work on modifying a Bimini top to my (admittedly!) non-standard dimensional requirements. 
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Needed to fit it fore and aft, to determine how much the top needed to be shortened, in length.
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Finally decided on 8 inches, which required a 4-inch Z-fold in the middle.
Tried to use basting tape again (while studiously avoiding where the sewn seams would be!)    but the work table wasn't smooth enough, or flat enough, to permit a good seam layout.
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Moved it over to some nice flat concrete. 
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Once I had the Z-fold firmly fixed, I sewed it up on the heavy-duty Sailrite machine; the fabric was bulky enough to require more wrestling, than pic taking.

But here is how it looks on the boat! 
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Look, Ma! It FITS!! 

All the dimensions right where I wanted them! 
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A closer look at the Z-fold.
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Yeah, the seam got away from me at the end;    apparently, you should lift your foot off the pedal, when you're fighting the fabric! 

Next step was to melt some access holes in the fabric, to accommodate the eye straps.  By melting instead of cutting, I hope to avoid future fabric fraying.
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Closer view:
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Dragged out the solar panel to figure out how I was going to attach it to the Bimini top.
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Decided to mount it longitudinally, rather than transversely, which I felt would have sagged the rear of the Bimini top, too much.
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Wonder where that idea came from? 
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If ever there was an application . . . . . .
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 . . . . .  required to secure a fastener to an eye strap . . . . . .
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 . . . .  a taut-line hitch, is that application.
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Easily loosened, easily snugged.

Bimini top eye straps, are wildly useful on a small boat. 
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Wired up the Anderson 35 Amp connector at the coaming end and the two MC4 solar connectors at the array end.
Why not just cut off the MC4 connectors and put in a coupla butt splices? 
In case I ever need to add a second solar panel, it will be much easier to just plug everything together.
Hooked it all up, plopped it on top of the Bimini top and dragged the boat and trailer, out of the carport and into the sunshine!! 
(Ya gotta love a boat you can drag around, like a semi-recalcitrant wheelbarrow!!) 
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Annnndddd . . . . . .it didn't work.   
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Mystified!! 
Checked the MPPT 75/15 specs again: Requires a minimum 5 volt differential, between solar panel and charge controller.
Ok, the panel outputs 18.6 volts; 18.6 volts minus 13.3 volts, equals 5.3 volts.
Should be GOLDEN!!  Went in the house and dug out the user guide for the panel.
Hmmmm . . . . .   open circuit voltage = 18.6 . . . . right, . . . .  uhhh . . .  what's this?    . . . .  maximum power voltage = 15.9 . . . . .
DOHHHH!!! 
For those following along: 16.73V - 13.3V = 3.43V, or a little over HALF    of what I need, to make the charger work reliably.

Went back and checked my pics from a year ago, in April, when I first got the panel.
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Unloaded voltage at 10 am, last April.
Nothing like not understanding the very specs, you're trying to engineer stuff with, Charles!! 
You used to be better than this, at all the electronic stuff!! 
After my ego got unstuck from its:    THIS ISN'T HAPPENING!!    loop, I considered my situation.
Nothing like Total and Abject Failure, to free up the mind to try out different things. 

Swung the boat and trailer around, so the panel was more into the sun.  Picked up about a ¼ volt (238 millivolts).
Picked up the panel and oriented it at an angle more toward the sun and got another ½ a volt.
HAH!!    4.18 volt differential!    (Still need 5, though.) Got out some alligator jumper clips and put a D-cell flashlight battery, in series with the solar panel.
(And you thought I didn't need the MC4 connectors!!) 
It started charging!    Yayyy!!    Although, it was current-limited to the current capacity of the D-cell.
(Which I had expected, what with the Peukert Effect and all; I'm not TOTALLY incompetent at electronics, all current evidence to the contrary, notwithstanding!) 
OK, still horrendous, but it proves the charger works as advertised and the solar panel also works as specified.
Also proves that God still refuses to repeal any of the Laws of Physics, just for Charles.
Apparently, the only thing actually malfunctioning,    is the Engineer!! 

So now, what to do? 
I had always prepared as a contingency, installing a second panel if it was ever required, ya know, just in case my maths wasn't mathing. 
I am using a 35 year old Sears Die-Hard 18 lb thrust, 1 hp trolling motor; I had it on Urchin for three years, in the early '90's.
I had made up a velocity/current draw/distance nomograph back then, so I had a very good idea of the energy requirements and capabilities of the motor.  If it flakes out on me, newer replacement trolling motors (e.g. 24 lb thrust) would draw more current and I would then be behind the eight-ball, on solar panel current replenishment.  I also draw more energy at night, powering a CPAP machine, so the math was very, very, close.
100 watts replenishing my 18 lb thrust  motor, would be roughly equivalent to 200 watts replenishing a 24lb thrust motor hence, my back-up plan.
I went in the house and ordered a second 100 watt solar panel, that cost far less than what a 30 watt solar panel I bought 20 years ago, cost me; 50 cents a watt, is astounding to us old-timers!! 
(I even remember when 10 bucks a watt, was a Deal.)
Wire them in series and their maximum output voltage should be around 31.8 volts and I bet it'll charge THEN, dammit!!!   
(Guess keeping those MC4 connectors intact, is going to pay off sooner than I thought!) 

Since I was all done with solar panels until the Amazon truck graces me again, I went to work on some more details; like sanding down the plugs on the teak hand rails.
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And after two coats of varnish:
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Three or four (maybe, five or six!) more coats of varnish to go!
Stuck waiting for parts to come in from Sailrite and Amazon, is a godsend for getting lots of niggling little details done! 
Even something as simple as having to put paper towels in the boat.  Trivial task, but it still has to get done.
Even got the Harp Lager for christening the boat, ordered!!    (Not available, locally.)
Or re-working a re-entry strap end loop, that was a little too snug for the shackle, at one end.
Small details, but they all matter.

Charles Brennan