Thursday, May 19, 2011

Blue Sea Sub Panels

I'm really loving the Blue Sea products.  So far everything feels like it's built very well and the wiring is well laid out.  An intuitive wiring plan is important because boat electronics get VERY complicated, and the easier things are to wire, the more likely you'll be able to trouble shoot it years after the install when something breaks at 2AM in rough seas.




As the CS27 has a relatively small area for mounting electronics panels, I need to consolidate similar devices into sub-panels that save room on the main breaker panel.  It also makes boat operations easier for my family who may not want to search through rows of breakers just to enable a portable DVD player on a 12V accessory plug.  Sure, it's ideal to have the VHF on its own breaker to reduce interference, and increase reliability (less dependence on other devices), but at some point you need to consider the big picture.  I find the probability of these risks to be very low in my design, and the benefits of circuit consolidation to be overwhelming.  I want to keep my boat's interior as clean and uncomplicated as possible.



A secondary benefit of using these panels is that it allows me to locate the aggregation point for device wiring wherever it is most convenient.  By including both positive and negative feeds on the panel it lets me bring device wiring directly to this subpanel rather than having to split positive and negative to different areas.  This again simplifies troubleshooting, installation, and increases the intuition of the design.  If space gets tight in the engine area or electronics locker, I can relocate a subpanel to a locker bulkhead.  I love this flexibility!



I will be using one of these to feed the instruments, including chart plotter and auto pilot.  A second panel will supply power to miscellaneous electronics including 12V sockets, stereo, and VHF.  In doing so, I can reduce my main breakers to a total of eight rather than fifteen.  Not only a big saving in panel space, but also in panel cost.



I'll add subsequent blog posts as I begin the installation.  Hopefully that will be soon; If  I can just get through this bow hatch fiberglass work!


Sunday, May 15, 2011

Chartplotter Selected

West Marine is and Raymarine are running a dual promotion now which results in the Raymarine A70D chart plotter having a $500 rebate, and then West Marine throws in a $200 WM gift card.  That's a pretty hard offer to refuse given how close this leaves the A70 to the A50 I was almost going to buy.  After looking at them in the store I think the A70 is a bit more readable having a slightly larger screen, although same resolution.  I'm not going to need or use the fish finder functionality - couldn't stand the idea of losing a zillionth of a knot in speed, or of my beloved sailing vessel being confused with a fishing boat!  But with this discount it's tough to pass up the offer.

The biggest reason I selected this unit is to keep the instruments consistently speaking SeaTalk.  The plotter will have bidirectional communications with the X-5 SmartPilot computer which should be convenient.  The only thing I appear to be sacrificing is the ability to integrate radar in the future.  I'm not sure I really need radar in my intended use of the boat, so I can't really say that this is going to be a future point of regret.  What I do know is that I picked up a nice plotter for a price I'm happy with.

I also purchased a NavPod angled pedestal guard in 1" tubing to match my current pedestal.  That should make the plotter much more ergonomic in use.  I'm not keen on using a full NavPod enclosure for the plotter though; It's awfully large and painfully expensive.  I may end up going that way, but for now I'm going to see if I can fabricate a worthy bracket for it.

I find it interesting that I can order just about anything from Defender and have it in two days, but almost anything I order from the local West Marine store is a week's wait as they onlyy get orders in once per week.  That's a long wait for an exciting toy!

Wednesday, May 11, 2011

Bow Hatch Installation



As usual, everything was going according to plan, when an earthquake comes along and wrecks my estimates.  In this case, it involves the bow hatch installation.  The original hatch was beyond salvage (or shall I say, the necessary ambition and effort).  I chose a Lewmar Medium Profile Series 60 hatch as a replacement.  What I had planned for a day of work turned into an aggressive week of work with many nights under the halogen work lights at 11pm.  Wish I could get this boat into my driveway!

The Lewmar 60 is very close in required cutout size to the original hatch, falling just under the required dimension.  I thought I might just get away without having to shim it, but as it turns out I needed to build up a little bit all the way around.  I'm guessing about 8 layers of 10oz. cloth will do the job perfectly, which isn't too big a deal.  Unfortunately, there was an additional detail which did not enter into my planning when I purchased the hatch.  The Lewmar's corners are rounded, not square.  Ugh.



In order to get a proper structure and seal I needed to build out a core and laminate to match the new hatch's corner radius.  That's a lot of fiddly time consuming work, although not particularly difficult in and of itself (at least now that I've been doing glass work for almost two years!).

I began by making a corner template out of some scrap cardboard I had hanging around the boat.  I simply traced out one of the corners, cut it out, and verified that all corners matched it on the hatch.  Next, I used that template to cut out four pieces of 1/2" balsa core on the shape of an "L" with the appropriate radius.

I used a Dremel tool with a small router bit (perhaps a #654? not sure...) to rout out the core material between the top and bottom laminates.  This made a nice channel to set the new core blocks into.

Next, I wet out the corners lightly with un-thickened epoxy as called for by all the West Systems guides.  Then, I mixed up a batch of epoxy thickened with colloidal silica, although high-density filler would be excellent as well.  I went for somewhere between mayonnaise and peanut butter consistency.  After buttering up the balsa pieces and the recesses, I pressed them into place, filleted the edges, cleaned up residue, and let it fully cure.

Next step was to grind out a beveled surface inside and out (both sides of the deck) at each corner.  You can see from the picture approximately what the shape of this grinding looks like.  I made it as uniform as possible.  I ended up laminating 8 layers of 10 oz cloth first.  Each piece was approximately 1/8" smaller than the previous to help match the taper.  I also left a little fuzz hanging over the balsa core edge which I'd clean up later.  This leaves a strong edge as the cloth tends to fray during handling, especially on tiny pieces like these.

After grinding the 8 layers to a more uniform surface, I surveyed the repairs.  Three out of four needed a little piece or two added in various shapes to help bring the profile to its needed shape.  I then gave these a kiss with the grinder to smooth things out.

The next step is to add the long laminate shims to bring the edges out to match the corners.  This is another set of 8 layers, again with 1/8" tapers.  This time I built up smaller to larger as I was less concerned about bonding surface do to how little load these will carry.  I just wanted the smoothest possible end product.  It took forever to cut out the 32 18-19" x 1-1/8" strips, but again, it's not very hard to do, and luckily I could do this at home to prepare.

My final touch is to lay down gel coat in the new corners as some of the repair is exposed.  I also needed to drill and fill the original hatch mounting holes as they are exposed when the new hatch is installed.  So, another set of gel coat repairs to do.

After installation, the hatch cut out was finally the correct dimension for the new hatch, and a normal installation could proceed.  At the moment I'm leaning towards through-bolting the Lewmar hatch rather than using wood screws as CS originally did.  Although I'm not a fan of having those bolts exposed below decks, it is a more seaworthy installation.  I'm not worried so much about the hatch being ripped off the boat, but  I noted significant stress cracking around the original  surface mounted holes with some being pulled up almost 1/16". 

Based on these observations I'm not convinced that a surface mount is adequately reinforced.  Perhaps a good epoxy potting job will make a difference here.  I can always go back and through bolt if I notice any signs of fatigue.  I'm hoping to complete this installation over the weekend, so I still have a few days to noodle this idea around in my head.

Tuesday, April 26, 2011

Fog and Rain Slowing Me Down


The fog this morning was so thick I could cut it with a rigging knife.  It had also left things so humid that the boat was completely soaked in water droplets.  The deck was so wet that even when I toweled off a section to work on a new rivulet of water would run through the cleaned area within a few minutes.  This pretty much stopped me from working on the stanchions first thing.

Instead I spend some time replacing the dodger clips.  I'm not sure why anyone would install chintzy plastic clips for something like a dodger, but alas, there they were in all their cracked and faded glory.  I bought a bag of 25 twist lock clips from Sailrite which are all stainless and much higher quality.  The hole pattern is ever-so-slightly different than my originals, but close enough to work.

I ran into a few holes that had been stripped out over the years of over-tightening.  These will be drilled out over sized and then filled with thickened epoxy.  After a good drying time I'll re-drill them and install the clips.

Last night was the first good rain Ravat has seen without a tarp cover.  My makeshift cockpit drains did their job well.  Unfortunately, the many holes in the cabin where grab rails pass through let water in.  To address that issue I lightly countersunk the interior side of the holes and filled with thickened epoxy.  That will stop the rain from coming in while I'm doing other things.  The grab rails can't go back on until the panels are back up, and that will be a while yet.

I did manage to get another set of stanchions mounted on deck before the storms kicked back in.  I have also packaged up my original life lines and prepared them to be sent to Rigging Only in Massachusetts.  After researching life lines on various forums I kept seeing this company's name popping up both with favorable pricing and excellent quality.

My original lines were 1/4" plastic coated.  I will be replacing them with 3/16" uncoated 1x19 316 stainless lines and machine swaged fittings.  This is in keeping with current safety best practices.  They also look very cool.  I'll be anxious to get them back, as I'll no doubt have all of the stanchions ready by then.

My final act of boat-buildery for the day was some work on the stanchion backing plates I've built out of 1/4" fiberglass board.  This stuff is almost ipossible to cut, but will do the job very nicely.  I needed to make the non-gate stanchion plates 1/2" narrower to fit properly.  I also needed to adjust the shape of the gate stanchion plates to ensure they'd go in level.  I then pre-drilled the holes, and now all should be ready to mount as soon as I have the over sized bolts they'll require.  That's an upgrade I feel very good about.

The weather continues to look promising for the weekend, so I remain optimistic that I'll be able to get the barrier coat applied soon.  She's going to look incredible!  And once that barrier coat goes on I will reward myself by installing the new Ravat graphics on the stern.


Friday, April 22, 2011

Electrical Planning: Wiring Schedule

Having nearly completed the structural work, inhibited only by temperatures, I am now moving on to the electrical, plumbing, and mechanical systems.  The electrical system seems to be the one which is most demanding of my thoughts at the moment.  I have discovered that most of the wires in the boat are not correct in one way or another.  I believe I have located one or two which are terminated properly, and we wont' even discuss the rat's nest that sits above my engine bay.  Time for some radical refitting.

The first thing I did was to rough out a list of every major electrical component I have on the boat, and any items which I intend to realistically add to the boat within a reasonable time frame.  I then started messing around with options for combining these devices into circuits based on load, locations, or use.

The next step was to grab some images from Google and start putting these into a diagram which includes a DC panel, and each device.  The devices were then "wired" with lines on the diagram to show circuit paths.  After ensuring I hadn't forgot anything, power consumption per device was recorded.  This was mostly done by downloading user guides or specification sheets from vendor web sites.  In some cases I found a device which was "close enough" to what I have, or perhaps a bit more powerful to be conservative.

The final step involves estimating wire run lengths.  This is critical because ABYC codes require that an appropriate gauge of wire be used with respect to lengths of run and amps of load.  These wire gauges are identified using voltage drop tables.  Since my boat is about a 30 minute drive from my home, and I can't be there all the time, I needed an alternative model to plan these wire runs.  I ended up creating a roughly dimensioned drawing that would get me "close enough" to pick wire gauges.  I have posted a PDF version of the Rough Internal Dimensions Drawing on this site for reference.



The final drawing tells me the length of each cable run, how many amps the circuit may potentially carry, how it is fed and grounded, and the size of fuses.  The drawing is evolving frequently, but I'll try to keep the on-line version relatively current.  I have also uploaded the Ravat Electrical Plan file as a PDF document for reference should anyone else feel like refitting a CS27 and find it useful.

First on the agenda is getting the AC charging system installed, and the batteries reinstalled.  This of course is awaiting weather warm enough to allow me to paint the aft cabin bulkheads and cockpit lockers.  Hopefully the weather will soon cooperate and release its tenacious grip on winter.

Monday, April 11, 2011

A Little Progress in a Lot of Places

I've been nibbling away at the to-do list a little bit at a time.  No big items to cross off yet, but a big push forward along a very wide line.  
  • I have completed the re-installation of the transom steering quadrant cut-out, this time through-bolted and bedded in butyl.  The transom area is also fully potted in thickened epoxy, so it's solid as a rock and watertight.
  • Backing plates are installed on the toilet intake, head sink drain, and waste discharge holes.  I used 1/2" FRP sheets from McMaster-Carr to save laminating time, and they came out great!  Much, much better than the rotten plywood I peeled off the hull.
  • I fought a brutal battle with the cockpit drains.  The through hulls were installed with locking nuts rather than proper seacocks, and when the boat was built they gel-coated the threads.  This made it impossible to remove the fixtures.  My recourse was to break out the big Sawzall and cut a star patter in the through-hulls after slicing off the in-line valve.  A quick grind with the Dremel took care of the mushroom fitting, and a few hammer taps later it all came out.
  • The jib tracks were reinstalled using 3m 4200 because I didn't want to wait for the butyl to arrive.  My mistake, my regret.  I have a mess to clean up now, but I hope they will remain sealed.  If not I'll clean them up and use the butyl.
  • Another few blisters I'd missed on the hull have been faired.
  • The long stress cracks on the keel-hull joint area are now repaired.
  • The rudder hardware is 90% faired over with my favorite 3m Premium marine filler.
My next milestone will be installing the backing pads on the cockpit drains, rebedding the drains in the cockpit sole, and getting the new seacocks in place so the rain won't fill the bilge.  Pumping the bilge is a colossal waste of boat building time!
   

Monday, March 28, 2011

Grinding the Keel


On March 26, I spent a brutally cold afternoon grinding away on the keel.  The trusty 8" random orbit sander continues to impress me as having been a good purchase.  My goal was to finish removing the anti-fowling paint from the keel, and then do some light grinder fairing of the fiberglass work on the keel-hull joint.  Both of these objectives were met, and I'm very pleased with the results.  The smooth glass work looks a million times better than the messy 3M 4300 job it replaced.

The only thing I'm debating now is whether or not to repair the minor, but long stress cracks in the gel coat right above the keel-hull joint.  They run almost the length of the keel on the port side.  All are tiny spiderweb sized lines which I think the barrier coat would fill.  Interestingly, there are no cracks at all on the starboard side.  I have requested an estimate from the composites specialist at my boat yard.  He did amazing work on the topsides and decking, so if the cost is reasonable I may have him do it.
My next project will be to apply fairing compound to the keel-hull glass work and smooth out the fabric texture.  I'm thinking two thin coats ought to do it.  My only problem now is waiting out the battle between Winter and Spring.  Temperatures just aren't quite warm enough for Epoxy, so I'm in an anxious holding pattern.

At the point all I should need to do is re-install the rudder and I'll be ready for barrier-coat.  Now THAT will be a dramatic improvement!