Monday, June 26, 2017

Reclaiming The View

If your boat has Beckson ports, or any ports which feature polycarbonate (Lexan) lenses, then if those ports are more than a couple years old, they are turning brown and hazy.  Lexan does not do well with UV exposure, but it is used for port light applications because it is easy to injection mold.

For years, I have been removing the affected port lenses (That's what Beckson calls the transparent part) and laboriously rubbing them out with Meguires compounds (#17 and #10).  It helped, but it was a losing battle - the brown coloration was going deeper and deeper into the outside surface of the lenses.

Well, it turns out that that auto manufacturers like that easy injection molding too, and so on all modern cars, those clear headlight covers are also Lexan.  And they too turn brown and hazy.  Now, a product to address boat ports is a lot less likely than one aimed at auto owners trying to refurbish their headlights, and, no surprise,  several companies have met that need.  I trust 3M:


So I bought one of their kits.  It has a velcro disk that is to be chucked in your electric drill and a number of abrasive disks.  It also has a rippled sponge (it's the orange thing in the package picture) and some fine rubbing compound in a pouch.  There is also a wax, but I didn't use it - see below.

Before
So here's what I started with.  You can see how the UV has attacked the plastic, except where the gasket had protected it around the edges.  It's brown, and it's hazy.  The kit first has you go after the surface with a 500 grit disk.  They suggest doing it dry, but the disk materials are all waterproof, so I did it wet - this has the advantage of keeping the dust generated by removing the surface layer suspended in water and keeps it from clogging the sanding disk.  Just sprinkle on s few drops of water.  And boy, did it make a terrible-looking brown slurry out of that decayed Lexan.

After 500 grit
I wiped off the slurry and changed to the next finer disk:  800 grit; I also did this one wet.  And the slurry this time was white - I got all the brown off with the 500 grit!  Now, the purpose of each successively finer grit used is to remove the scratches made by the previous grit, so after the 800 grit treatment, all the 500 grit scratches should be gone.  After wiping off the slurry, I found that I had been a little too impatient and needed to go over the surface again.

After 800 grit
Next on the agenda is 3200 grit.  This time the kit wanted it to be used wet, so, not breaking stride, I used water again.  Same drill - remove the 800 grit scratches.  It's starting to look clear!

After 3200 grit
Finally, after wiping down the lens again, I put on the sponge disk and applied a little rubbing compound to the lens.  Then, scrubbing it around a little so that it wouldn't spray all over the place when I keyed the drill, I turned on the drill and went over the surface a fourth time.

After compounding
Wow!  It's good, but...  So I got out the Meguires and used the #17 and the #10 on it.  This was way easier than in years past because all the hard work had already been done by the drill.

Much better!
Well, it's not quite like new, but this port is much, MUCH clearer than it has been for years.  I suspect that the remaining haziness may be in depth in the plastic.

The whole process took a couple of hours to do four ports, including the time to unmount and remount the lenses...  that's less time than I would have spent doing one port by hand, with more mediocre results.  And a tired arm.

The directions want you to have a medium speed drill, and I would second that.  You definitely want to use a variable speed drill, running at a moderate speed.  One of those single speed drills will turn so fast that heat generation will be a problem (especially if you follow the directions and do it dry...  don't do that).  It is also important to tightly control the drill so that less than half of the disk is in contact with the surface.  If you try to hold it flat, it will inevitably spiral out of control, and then you will likely gouge the surface with the edge of the abrasive disk.

Would I recommend the 3M kit?  Absolutely.  Even for your car.







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Tuesday, June 20, 2017

A Phone App Recommendation


All the newer phone apps that show or predict wind speed and direction have those little moving arrows to give an animated display of the wind flow.  But how many of them actually predict or show what is happening?  Not so many.  A pretty animated display is not necessarily accurate.

Windy (for both iPhone and Android) is not one of these.  This is the best wind app that I have seen.  Tho it covers the entire Earth, my experience with it is local, which is nevertheless perhaps an excellent test.   Windy successfully deals with the complexity of the three major wind channels (Strait of Juan de Fuca, Admiralty Inlet, Strait of Georgia) in the Salish Sea, and the mess of islands sitting right at their junction.  

By comparison, the NOAA "Northern Inland Waters" forecast seems to pick the worst spot in the area and report on that.  I suppose that makes sense from a safety perspective, but it has a tendency to limit boating unnecessarily, because wind speeds can vary dramatically between the southern end of the San Juans and the northern end, or from east to west.

I've been comparing reality with the little flowing arrows in Windy's screen for 6 months now, and from what I can see, it does an excellent job of describing the actual current flow pattern.  In addition, for forecasting it gives you the choice of using three different models.  I use the European high resolution model, ECMWF, but occasionally check the other two models to see how they differ.  The forecasts are also excellent.

The app has many more features which I I'll leave to you to discover.  Just for the wind forecasts this app is worth every penny of it's $0.00 cost!

Get it.




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Monday, June 12, 2017

Actualization

As with many projects, the design and planning stages take longer than the actual execution.  Making a new sail cover for Eolian's mizzen was one of those projects.  I started thinking about this last summer, while hanging on the mizzen boom by one arm, way out past the stern rail, making up the fasteners on the far end of the sail cover.  I have been doing this acrobatic act for 20 years, but lately my shoulders have started to bother me, telling me that this process was going to have to change.  

Well finally last week everything came together and I was able to spend the time to put the plans and design to the test: actual sewing.

You really want to use a hot knife for this...

I unrolled the Sunbrella on the dock, laid out the pieces using a chalk line, and cut them out using my brand new, handy-dandy hot knife (you really want to use a hot knife for this work because it seals the edges of the cut, preventing unraveling).  The only tricky part of the layout was the placement of the cut outs on the side pieces for the lazy jacks.  To get these right, I tied the lazy jack lines to the boom at their design locations, and then stretched a tape measure along the diagonal that the top of the sail cover will make, taking the measurements where the diagonal intersected the jack lines.

Then the depth of the cut outs needed to be established.  I wanted them to be just deep enough so that the top of the cut out, which will be the bottom once the stitching to make the batten pocket is completed, would be just above that seam in the finished product.  Here's the detail on that:  I had determined that a 4.5" circumference would make a batten pocket large enough to accommodate the 3/4" schedule 40 PVC pipe that I was going to use as battens.  Adding a 1/2" seam allowance, I struck a "fold-to" line 5" away from the top edge of the side piece.  Then I laid out the cut outs so that their ends were 1/2" (seam allowance) + 3/8" (allowing for the edging to be applied to the cut outs) = 7/8" from the fold-to line.

The rest was just sewing.  The cover is just shy of 12 feet long, and there is no place inside Eolian to stretch it all the way out.  But sewing it over the saloon table worked out OK.



I mentioned that I used 3/4" sched 40 PVC pipe for the battens (the gray kind, rated for outdoor use).  PVC pipe comes in 10 foot lengths; the sail cover is just shy of 12 feet long...  a splice was necessary.  I didn't want to use a coupling, since that would make a lump that would make feeding the battens into the pockets difficult.  It turns out that 1/2" sched 40 pipe has an OD just slightly larger than the ID of 3/4" pipe.  So I bought a short length of 1/2" pipe, cut two 12" lengths, a slit one side of each piece lengthwise on my little table saw.  That 1/8" kerf provided just the right amount of clearance to allow the 1/2" pipe to telescope into the 3/4".  Assembling with pipe dope gave me a smooth splice.

Almost done...
I added ties that go under the sail using black Sunbrella webbing and Common Sense fasteners (not visible in this picture - they're on the other side). 

The top zipper would be impossible to operate if its aft end were not stabilized - a short strap there is seized to the topping lift line.  The finishing touch is a tiny block seized to the topping lift line just above the zipper seizing - and a 1/8" line loop routed thru the block and tied to the zipper pull allows the zipper to be operated while standing on the deck, not hanging over the rail.  Doing this work was interesting...  I had to swing the boom out over the dock and stand on top of a ladder to reach the aft end of the boom.

I wasn't sure what I was going to do with closing off the aft end - I think I'll do nothing - the opening is not large enough to bother with. 

I still need to make a front panel that wraps around the mast - the zippers that will attach it to the sail cover are already installed on the sail cover.

And I haven't yet cut the lazy jack lines to length - I think I am going to fiddle with them a little more - I want to see how things settle in with some use.



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Tuesday, May 30, 2017

For The Birds


How about this visitor that showed up on our masthead recently?

Actually, birds sitting up there are not my favorite thing - not even our National Bird...  perhaps especially not our National Bird.  See, that guy weighs 10-15 lb.  And that thing he has his left foot on was not made to carry his weight, or even half of it.   Thankfully he is too big to get both feet on it.

That "thing" is the sensor for our wind instrumentation - a pretty essential thing for a wind-powered vehicle.  See the spinner (wind speed) and fin (wind direction) out on the end?  I've already had to repair the direction sensor once due to an obese bird sitting on it and breaking it.

So, despite the delite of our neighbors (m/v Konocti Bay, who captured the photo), I shooed him off by banging on the shrouds.



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