Digital Multimeter Revisited

In my last post I claimed that the digital multimeter I installed in place of the old analog meter was more accurate.  Professional engineer Bob Salnick, author of Windborne In Puget Sound, very gently challenged my claim, asking how I knew that the digital meter was more accurate than the analog meter.

Image from http://joyfulpublicspeaking.blogspot.com/2012/07/bogus-list-of-top-ten-phobias.html

Truth is, I don’t know.  My claim is baseless.  I just assumed (and hoped!) that it was true.  As I explored methods of verifying the accuracy of a multimeter this morning, I learned a few things:  1) I only understood about one-third of what I read about testing a multimeter for accuracy.  I think the concepts are fairly simple, but the details engage a vocabulary and set of technical skills that I don’t possess;  2) Cheap digital multimeters have no corner on the accuracy market.  My cursory reading of digital multimeter reviews revealed inconsistency in most lower priced models;  3)  Higher-dollar “marine” meters may well be quality instruments, but it takes a fair amount of reading manuals, consumer reviews, and technical reviews to be sure that what you are buying (or have) gives accurate information;  4)  A quality multimeter is expensive – as much or more so than a “marine” instrument.

So there you have it.  Apologies to all for spreading spurious information, and my thanks to Bob Salnick for his commitment to fact and his gracious spirit.

Digital Multimeter Replaces Analog Volt Meter

This just seems like a no-brainer.  We all know that everything with “marine” stamped on it means it cost 4-5 times as much as it ought to.  Sometimes this is justified – bronze or high-quality stainless hardware is pricy, and things that are made to last use high-dollar components.  Other times, though, those high prices are just an attempt to soak boat owners for more money.  I think that’s the case with volt meters for boats.  Earlier, I posted about my analog volt meter made by Blue Sea that costs $45.  It is has been on the boat as long as I’ve owned it – installed perhaps by a previous owner.  It was definitely better than nothing, but that doesn’t mean it was a quality piece of gear.  I’m learning now just how inaccurate it is, as I use my digital multimeter in its place.

I glued up a small bracket from scrap teak and .25″ plywood to hold the multimeter in place.  I mounted it today by drilling two small holes in the plywood back, counter sinking the holes for flathead screws, and screwing it into the bulkhead.  Here’s a photo of the bracket again:

Multimeter mounted in the bracket.

After cutting off the probes, I installed new ring connectors on the leads and attached the positive lead to the middle pole of the battery switch, and the negative lead to the negative bus bar.  I’ve attached hook-and-loop fabric to either side of the unit to hold it securely in the bracket.  Now I can test each battery’s state of charge and get an accurate figure.

Low-cost volt meter for your boat.

The state of charge at any given time is subject to interpretation.  The meter can give you a rough idea of current usage, and let you know when the voltage is getting very low.  It can give you a more accurate picture of the state of charge in a battery after the battery has been unused for 24 hours.  The multimeter can also give you an idea of the rate of charge acceptance for your batteries.  This information is useful in determining the health and status of your battery bank.  And, the information is a lot more accurate with a digital meter than your typical consumer-grade analog meter – I discovered through this project that the old analog meter was reading several tenths higher than was true.

The meter cost me about $10, and I’ve just ordered another from Amazon for under $10.  I would have ordered just a new set of leads and continued to use the meter as a tool also, but the with shipping costs, it made sense just to order a new meter for – literally – a dollar or two more.

Operations Locker – Part Finis

Short post on this, just a photo really.  I wanted to show you the “populated” inside of the locker.  It’s already messy!  Not really, but it could benefit from a couple of hooks for keys and a pencil/pen rack, which is just a block of wood drilled with 5-6 holes to hold writing tools, screwed to one of the doors on the inside.  And here’s the photo:

Inside view

Next little project is to mount my multimeter/volt meter bracket and wire it into the electrical system.  This link will take you to the previous post that relates to it.

Operations Locker – Part VII Installation

This is always the exciting part for me.  How does it look, fit, work with the rest of the interior?  Did I calculate right?  Did I blend the stain correctly to match the other woodwork.  Will it solve problems or create them?  Does it do what I hoped it would?  The only way to know is to install and use it.  But sometimes the installation can be a challenge.

I visited my local hardware store for fasteners of sufficient size.  Then offering up the cabinet to the designated space, I marked, drilled, straightened – all those things we need to do for installation.  I was a little concerned that the cabinet squared up to the space correctly, and looked visually straight and level.  Then after installing the fasteners, I was satisfied with the all of that.  In fact, I was elated.  Until I took a closer look, and discovered that somehow, the doors had managed to get uneven in the way they meet together.

How did that happen? I know I built it square, and went to pains to get the details correct.

Shouldn’t be too surprised that the doors don’t meet at the bottom if they don’t meet at the top.

Where did I go wrong?  Well, as I thought about it, I realized that the right-hand side of the cabinet (port side of the boat, actually) is hindered from lying flat and true to the bulkhead by the curvature of the overhead.  I had trimmed that corner of the locker, but not nearly enough.  As I backed out a few mounting screws from the port side, I discovered that I could put the locker back into square by pulling out the bottom corner on the port side.  What I needed then, was a shim behind that corner.  I rummaged through my scrap box for a couple of appropriately dimensioned scraps, and made the adjustment with them.  After that, longer fasteners were required (I moved that corner away from the bulkhead more than half an inch) so after another trip to the hardware store, I secured the locker permanently to the bulkhead, and now it looks like this:

Doors meet square again. See the overhead curvature on the right of the photo? It keeps that corner of the locker from laying flat against the bulkhead.

. . . and the doors meet squarely at the bottom too.

So the next step is to install the radios.  Straightforward with the VHF.  I ran the wires and antenna cable into the cabinet.  No problems.  The AM/FM/CD player was another story.  Nothing difficult about the mechanical or electrical connections – I just didn’t understand  how to connect it all.  It’s been 20 years since I installed a radio like this, and I didn’t realize that the memory wire must be wired. Not wanting to have a constant draw of millivolts to the radio, I didn’t connect it directly to the battery. In fact, I didn’t connect it to anything.  I didn’t realize that the radio wouldn’t power up without having it connected.  I thought it was faulty.  My slip neighbor plugged it into his wire harness (he has a similar radio) and of course it fired right up.  As we talked about it, he mentioned that he wires the direct battery wire (memory wire) with the regular power wire.  Ah, now I get it.  So I’ll try again tomorrow.  Anyway, final photos of the locker installed follow:

I’ll post Interior photos of the shelves with gear stowed after radio installation is successful.

Operations Locker Part VI – Interior Paint and Assembly

Pecking away at the final finish, I’ve got the varnish to a point where I can apply the final coat after it’s installed on the bulkhead.  I’ve painted the interior, and today I reassembled the pieces and installed radio brackets.

Three coats of white – including primer coat.

Reused old VHF brackets

I installed the VHF brackets, but not without modification.  See the lowest hole in the upright sections?  These are newly drilled, and hold the radio securely in the opening.  I had to use washers underneath the screw heads to ensure the screws wouldn’t penetrate all the way through.

AM/FM Radio/CD Player Bracket installed.

Not satisfied with simply turning down the tabs, I captured these under screws and washers.  Now it holds the radio very securely.

Loose-layed shelves to assess the full effect. You can see the radios installed now.

I assembled all the pieces and installed the radios in the openings.  It turns out that the wire chase wouldn’t work when I began to install it in the boat.  I hadn’t counted on how bulky the fuse holder is for the depth gauge, and it was very difficult to get all the wires inside the chase, then screw it down.  I finally set the chase aside, and went back to using plastic wire holders.

All put together.

Over all, I’m pleased and surprised at how polished it looks.  I had fears that it would be mostly junk by the time I finished, as I kept making small errors, and was so displeased with how the material cut and took finish.  However, once the radios were mounted and took attention away from the lower door, once the finish was applied, and the entire project had a look of completion about it, I was pleasantly surprised.  I’m also pleased at how well the finish and color matches the rest of the interior of the boat. I got the stain color just about right.

I still have touch-up work to do on the varnish.  I got a couple of sags from the top edges at the trim which needs to be scraped and sanded and carefully revarnished.

Previewing tomorrow’s post, my installation onto the bulkhead was not without its own drama.  Once I got the cabinet mounted and stood back to see that it was straight, I noticed that the doors weren’t closing evenly.  The trim was obviously different at heights where the doors met.  What could have caused that?  It was perfect before installation. . .   Now I realize that the bulkhead isn’t completely flat, and in fact is impinging on the right-hand corner of the cabinet, pushing the structure out of square.  I had trimmed the upper right corner to fit, but apparently didn’t do enough trimming, and will have to do some more to get the structure to mount without stress.

Operations Locker Part V – Applying Finish

Construction concluded with addition of cabinet door fastener and opening an inlet at the bottom for wires.  Next phase is finish application.

Door catch hardware installed. Only took two tries to get it in the right place.

Wiring access opening is behind the wire chase at the bottom.

Looking at the photo above makes me realize that I have to shorten the wire chase from the bottom so that I can allow wires to go to the radios.

I’ll spare you photos of the sealer coat of varnish, and just show you the first regular varnish coat, with white primer on the shelves.  I’ll paint the entire interior white as well, but not until the varnishing is complete.

 

 

I finished the mounting bracket for the multimeter.  This will mount to the inside of the bridge deck with screws.  The meter will be secured into the bracket with hook-and-loop tapes.

 

Multimeter mounted in the bracket.

Mounting bracket for digital multimeter, which I’ll use instead of my old analog voltmeter.

 

 

Sailing in the Wake of a Cold Front

I reached for the coffee this morning and noticed the thermometer on our window sill:  outside temp was 61F.  61 degrees on a morning in late August. . .  We opened up the house and enjoyed cool air coming in through the windows as we drank coffee.  We are so thankful for this house that overlooks the creek – we drink coffee every morning in this sunroom that has a water view.

A cold front blew through last night bringing hard rain, thunder and lightning.  After that, the temp dropped 15 degrees, all the rain water dried up, leaving low humidity with breezy conditions on the bay.  Sounds like a day-sail in the making.  Ruth had other plans for the morning, so I called my father-in-law, who also had plans, but promptly changed them when I asked him to go with me.

We cast off at 1015, Dad at the helm, and motored one mile out to the bay.  Pointing into the wind, I raised the main, unrolled the headsail, and we romped off to the northeast for an hour.  We skimmed along with speeds constantly in excess of 5 knots, occasionally touching 6 knots –  with a Length-Over-All of 27 feet, that’s a pretty good turn of speed.  This was the off-wind leg, so our aspect was pretty flat and level.  As we reached farther into the bay we left the protection of the shore.   The gusts were stronger, heeling us over more and creating more weather helm.  I finally rolled up a third of the headsail and that let us sail more in control.

Dad at the helm having a great sail.

Flat conditions with gusty winds, at least near shore. Winds were from the west, so we had flat sailing for a while. I love the light in this photo.

The air was so clear – 20-plus miles away, we could see the top span of the Chesapeake Bay Bridge.  Closer in, we could clearly see Kent and Tighlman Islands.

Chesapeake Bay Bridge – click to enlarge to see it better.

Okay, here it is again, cropped and full-sized. Now you can really see it.

We traveled 5 miles out and came about, taking a reciprocal course back to Rockhold Creek.  Now we are closed-hauled, and the gusts are pushing us around more and Dad’s fighting a bit more with the helm.  I contemplated a reef in the main, ultimately deciding that the calms and gusts balanced each other – a reef would have made the calms really slow.

Half way back, I noticed a fish trap to leeward – we were either going to have to tack, or we would squeak by.  We squeaked, but it was close:  maybe 40 feet to spare.

Passed by a slim margin.

The wind strengthened.  I flattened the main, hauled it closer to center, and sheeted the headsail in tighter.  We were overpowered by the gusts more often now, so Dad steered right on the edge of constantly luffing.  That also kept us close to our course back to Rockhold Creek.  We finally came about again, heading northwest toward the breakwater, when we struck sails and motored the rest of the distance.  It seemed calm and warm inside the breakwater.

We tied up at 1245 and went in the house for a post-sail cup of coffee.

Operations Locker Part IV

Digging through my left-overs and wood scraps, I realized that I had some other un-milled teak that I could use for the locker door trim.  This is dense, heavy material, and I think it’s teak.  I bought it at Sailor’s Exchange years ago, when I still had some store credit, and used some of it to build the teak fore-hatch on Cay of Sea.  If I ripped strips off of one side of this lumber, it would be much safer than trying to re-mill the piece of decking I had in mind.  The width of the board gave me the perfect dimension for the trim.

It was easy to rip strips off of one side of the board, and with no safety hazards.

Before sanding and smoothing.

No fasteners for these thin pieces.  Just glue.  The challenge is clamping in the right location.

This glue takes about an hour to set up an initial bond. I had three different periods where I just had to wait for the glue to cure before I could move on to the next piece.

Three sides of the first door done. I got one strip done on the remaining door also.

You’ll have to wait for the next post to see the doors trimmed out, as I ran out of daylight today.

A few weeks ago, while worrying over my batteries, I struggled with the old Blue Sea analog volt meter that was on the boat when we bought her.  It doesn’t give very accurate information, and is wired up with a poor connection.  Not sure why I’ve put up with it this long, as I’ve long thought it would be a simple matter to connect a cheap digital volt meter from Harbor Freight (or some such place) and have it “permanently installed” with the use of a bracket, running wires directly to the the battery bank selector switch.

I began work on that today, cutting tiny little pieces of plywood and trim for the bracket, sized to fit the volt meter.

Little bits of trim to fashion the bracket.

There are no clamps that will hold this stuff together – it’s too small. So a couple of straight scraps lightly nailed down to the work surface provide brace points. The wedge-shaped pieces provide the clamping pressure.

Wax paper keeps me from glue it all to the work surface.

My old meter looks something like this, except mine has fancy red highlights that show different charging voltages for different battery types.  $45 for this.

$10 for a digital volt meter? Sounds good to me. If it had “marine” stamped on it somewhere, you’d pay $145.

Have to glue one piece of trim on at a time.  This is a little fussy, but who’s in a hurry?  I’ve waited 10 years to change this on my boat – guess I can wait a few more days to glue and clamp all the pieces together.

Operations Locker Part III

Hinges are hard.

This week I discovered that I didn’t understand how hinges fit onto cabinet doors.  I discovered this 4 times.  Four separate trips to the hardware store for hinges, buying, returning, reevaluating, coming home with different hinges to try.  I wanted to avoid using a piano hinge screwed into the end-grain of the plywood doors, and I wanted the hinge to be on the inside – hidden from view when the cabinet was closed.  Anytime you can avoid screwing into end grain. . .   Anyway, I finally realized that the lowly piano hinge screwed into end-grain was going to be the only answer, apart from redesigning the doors.  I also realized that the reason a piano hinge will work okay is that there are 10 little screws that fasten it to the end-grain.  10 little fasteners that hold moderately well, are as good as two larger fasteners that hold really well.  So I used a piano hinge, and it’s going to be fine.  Here are a few pics of the doors mounted.

A bonus: the hinge covers the end-grain of the door!

Note the gaps and slight differences in mounting. Try as I might, I didn’t manage to get the doors symmetrically mounted. Fortunately, trim molding hides a multitude of sins.

Radio access door open.

I have a piece of oak trim of the correct dimension that I’ll cut down to a narrower breadth.  This will nicely cover all the gaps and imperfect finish where the saw chipped the veneer.  I also have some teak decking that could be re-milled to the appropriate dimension.  Hmm. . .  that would match the saloon finish better than the oak.  Not sure what I’ll do yet.  Re-milling pieces that small comes with some safety risks.  Even with pushers and holders to run the stock through the saw, it’s difficult to get it right.  I’ll have to think about it some more.

Rhode River on a Monday

We got away early this week for an overnight, the winds dictating our destination to Rhode River.  We enjoyed an incredibly serene sail of 3.5-4.5 knots with easterly winds giving us a beam reach for several hours.

En-route we encountered a parade of daysailers in tow.  Perhaps a yacht club or sailing center loan to a summer sailing camp.

Reminiscent of a mother duck with ducklings.

Nothing really remarkable about the event – I just like the light in this photo.

We made our left turn at green #1 and made our way up the West River, then north into the Rhode river.  A look at the google map below gives you an idea of what a warren of creeks and coves constitutes Rhode River.  It’s great for exploring, and we’ve only seen a little of it.

We always anchor in the north end above the north-most island.  Actually, it’s the only island.  The island pictured south of that is not really there.  It is an extensive shoal now, with nothing above the water.  We know people who have lived on Rhode River for 60 years, and they remember the island back when it had trees, sheer cliffs, and a beach.  This is a testimony to the action of current and the mobility of soil in a tidal zone.  Ironically, its name was “High Island,” and is still shown on charts of the area.

Early in the week is a great time to cruise.  Anchorages are sparsely populated, and that was the case this past Monday night.  We shared the northern cove with one other boat, which was anchored 500 yards away from us – we could barely see them.

Early to bed.  Time on the water is exhausting, and the constant motion of the boat takes more out of us than we anticipate.  We showered and briefly read our books before conscious thought ceased for the day.

Our new LED cabin lights worked perfectly.  I am very pleased with the amount of light shed and electricity used.  The reading lights also worked just as I had hoped.  They are infinitely adjustable and the neck is long enough to allow us to position the light for maximum benefit.  They couldn’t have worked out better.

Morning dawned, but I wasn’t awake to observe the event.  Uncharacteristically, Ruth was.  She made a thermos of coffee – and drank it all!  That’s usually my trick at anchor.  I didn’t rise until 0800, at which point we made more coffee.  The weather forecast included rain and strong southerly winds for the trip home, so we got underway by 0930.  As we passed Camp Letts, we had fun watching the daysailers ply back and forth.  I never went to sailing camp growing up, but this looks like such fun to me!  These kids looked like they were having a great time.

YMCA Camp Letts has an Optimist and Laser fleet.

Conditions on the river(s) were benign, but once out on the bay we got the typical Chesapeake chop of steep waves and short periodicity.  15-18 knots on the nose makes for a rough two-plus hour ride home.  There was no avoiding the crash-and-bash.  Instead, I went east longer than usual before turning south.  This allowed us to take the chop on our port bow, and somewhat quarter the waves rather than plowing straight into them.

Photos of rough conditions never turn out well, but I thought I would try. I couldn’t level the horizon anymore than this in post-processing. The camera is in sandwich bag, but I’ve sharpened the image a good bit.

We were continuously sprayed by waves from the plunging bow.

This looks really mild compared to reality!

As we drew into the arms of Herring bay, the seas moderated and the wind backed around a bit due to land-effect.  We motored the final 3 miles under much calmer conditions, backing into our slip by about 1215.