Bimini Canvas: Cost

In the "last" post (OK, now this one is the last post...) on the bimini canvas renewal, Kelvin asked what the final cost was.  I'm afraid I can't give that because I used some supplies from earlier projects.  But what I can do is to make an estimate on materials costs, based on the Sailrite catalog I have here on board (check the Sailrite website for current prices):

Item	Quantity	Unit Cost	Extended Cost
Sunbrella, Erin Green, 46" wide	10 yd	16.95	169.50
DuraSkrim	10 yd	2.95	29.50
Binding tape, 3/4", Erin Green	80 ft	0.50	40.00
Zipper, #10, 48"	6	7.50	45.00
Zipper, #10, 60"	4	8.70	34.80
Zipper Pull, #10	10	1.70	17.00
Zipper Stop, Stainless	2 packs of 10	2.50	5.00
Common Sense fastener, male	50	0.60	30.00
Common Sense fastener, eyelet	17	0.195	3.32
Rivet	100	0.15	15.00
Seam Stick, 3/8"	1	8.95	8.95
Seam Stick, 1/4"	1	6.95	6.95
TOTAL			$405.02

I also bought some tools that, tho they were used in this project, will be used again in future projects.  I don't know if these should be charged against this project or not (you decide), but you should definitely have these tools to do the work:

Item	Cost
Rivet Setting Tool Kit	89.00
Common Sense Eyelet Hole Punch	69.50

I did not include the cost of the thread because I bought a large spool years ago and have been using it since.  You definitely want the Teflon Tenara thread or equivalent - it will outlast your boat.  Don't settle for polyester thread.

And finally, you need a heavy-duty sewing machine to handle this.  I heartily recommend the Sailrite LS-1 or LSZ-1 (zig zag - if you intend to sew sails).  They are expensive and worth it.  We got ours used for less than half the new cost.


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Bimini Canvas: Cost

What is it about dark gel coat?

Cleaner/wax application half done on the sheer stripe

What is it about dark gelcoat colors?  They seem to oxidize so much more quickly than the white.  Red is the worst, for some reason.  Dark blue is a close follower.

Could it be that their color absorbs infrared (heat) radiation more readily, making them hotter?  (Chemical reactions double in rate, roughly, for every 10° rise in temperature.)

Could it be that the white pigment (almost assuredly titanium dioxide) does a better job of protecting the interior resin from UV than the pigments used for the dark colors?

Or could it simply be that oxidation on white doesn't show because it is, well, white?  Actually, having rubbed out Eolian's entire hull several times during our ownership, I'd have to say that the oxidized layer on the white is definitely thinner than that on the green.

So I kind of think there is something special going on with the dark colors.  It is that way for automotive paint too...  the dark colors, and especially red, fail first.

What is it about dark gel coat?

The Third Shoe Has Dropped

Finally, I have completed the last of the three cockpit bimini canvas pieces:  the center section.  This panel is zipped to each of the forward and aft roof panels, meaning that its size is completely dependent on the placement of those two panels; they had to be completed first.

But because the old center panel had to continue in service until the new one was fabricated, the forward and aft panels had to be properly located.  In other words, because I did this work in sections instead of all at once, the new roof duplicated the old completely...

Because the old center panel fit perfectly, rather than pattern the center panel with DuraSkrim I chose to simply roll out some Sunbrella and trace the outline of the old center onto it.  The size is not terribly critical; instead it is the zipper placement that is crucial.  That being the case, I did a lot of measuring and annotating on the old center panel:

Again, placement of the zippers is what controls the fit here.  So I measured outside-tooth to outside-tooth at perhaps a dozen stations along the old panel.  Then, when applying the zippers to the new panel, I duplicated the station locations and ensured that the zippers conformed to the measurements.

I have learned thru this project that zipper position in a lengthwise direction is also critical, especially when there are pairs spanning the length.  To make this work out properly, I followed these steps:

• Locate the centers of both the old and new panels by folding in half, and mark them.
• Install the old center panel, and transfer the center markings to the forward and aft panels.
• Work on one edge at a time, I started with the aft edge.  Install one of the new zipper halves to the aft panel zipper.
• Hold up the new panel, matching the center marks.
• While continuing to hold the panel in place (you may need help here), make match marks on the new zipper half and the center panel an inch or three away from the center.
• Remove the new zipper half from the aft panel.
• Position the new zipper half on the new panel using SeamStick basting tape, matching up the match marks.  Note:  at this point, with no other reference it is not possible to exactly locate the zipper width-wise.  Instead, using another new zipper half on the opposite edge, simply ensure that zipper placement will allow both zippers to fall approximately equally on the fabric.  Exact spacing at the measurement stations will be established when the opposite zipper half is installed.
• After sewing the first zipper half, take the panel out to the cockpit again and zip it up.  Install another new zipper half on the other aft panel zipper.
• Pull the panel firm athwartship, and make match marks on the new zipper half.
• Following the steps above, install the second zipper half.

At this point, zipper installation is half done, with the attachment to the aft panel complete.  Complete the forward zippers in a similar fashion, with these two modifications:

• When establishing the position of the first zipper half, match up the centerline marks as before.  But this time, slide the panel a little port and starboard, watching for wrinkles to form and dissipate.  You are looking for that placement where there are no wrinkles - it may fall when the centerlines are not quite matched up.  Match mark the zipper half and the new panel.
• When sticking the zippers in place with SeamStick, be very, very careful to get the outside-tooth to outside-tooth spacing at the measurement stations the same as on the old panel.

Ta DAAA!

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The Third Shoe Has Dropped

Mooring Repair

While we were involuntarily moored in Friday Harbor, this unusual work boat (the aluminum one with the I-beam supported above the foredeck, not the white one behind it) dropped anchor near us.  On board were a diver, a man, and woman: the crew.  And two hefty gentlemen who did not participate in operations except to look over the side.   With nowhere to go, we speculated what they were up to...

As we watched, a diver went down with a heavy line.  When the diver returned to the surface, the woman used a heavy windlass (not visible below the bulwarks) and routing the line over a block on the bow she hoisted up...  a concrete block some 6 or 7 feet square and perhaps 18 - 24" thick.  Trust me, this was HEAVY - the bow of the boat dipped a lot.  Obviously a quite substantial mooring anchor.

With the concrete hanging from the bow, the man attached a brand new pennant line, looking like at least 1-1/2", to the anchor block (with a chafe guard of course!).  He then manoeuvred to a good spot and she lowered the anchor to the bottom.  He then attached a (very) used buoy to the pennant, and they all went home.

Conclusion?

The old mooring pennant had parted, releasing the buoy, which apparently fetched up on shore somewhere in Friday Harbor and was retrieved.  The action we witnessed was the reattachment of the buoy to the anchor on behalf of one or both of the observers, using a new pennant.

Conclusion #2?

That boat was ideally designed for mooring installation and maintenance.  We witnessed the maintenance part.  For a new installation, the new anchor would be placed in the bow, and then once transported to the desired location a hoist rolling along the I-beam would be used to retrieve it from the foredeck, roll it out forward above the water, and then lower it to the sea bottom.  Pretty clever design.

Mooring Repair