26 October 2011

The bridge deck

  One of the periennial drawbacks of the 1972-1978 series of the H25 is the lack of a mainsail sheet traveler.  Some clever people have fabricated one on brackets across the aft end of the cockpit.  This is not a bad idea and the sheetline leads are not too bad.  Putting one on the cabin roof, as many do with other boats, would place the mainsheet so far forward as to be utterly useless (except as a vang).  Moving the sheeting point forward on a boom is never good anyway-- mid-boom sheeting is a significant loss of mechanical advantage as well as a loss of sail trim.

  Those with mostly-original H25s will notice that the early H25’s boom is about a foot longer than it has to be.  The foot of the mainsail is designed to be at about 8’8”.  The boom which should be about 9 ft is more like 10' on some boats.  This was to extend the sheeting point, at the after end of the boom, far enough aft to connect to a single block at the back of the cockpit coaming.  This was the Cherubini-and-Seidelmann solution that enabled them to keep that lovely little egg-shaped cockpit surround.

  Part and parcel with the lack of a traveler is the lack of a bridge deck.  No one venturing offshore in any sized boat should have a hatch opening down into the cockpit pan.  Some people have said that keeping one or two hatch boards in is enough to keep most of the big stuff out; but remember that wooden boards float! --and in anything big enough to poop the whole cockpit you run the risk of one or more of the boards floating off and out of your life for ever.  Of course you could argue that in weather like that you’d have the whole hatch closed-up and when it’s nicer out you could have the whole thing open for air and convenience. But we singlehanders don’t like to leave any more than necessary in a state of needing attention as the weather escalates.

  The construction of a bridge deck on the H25 is an obvious solution to this two-pronged problem.  It provides a place to mount the traveler that is not too far forward of the end of the boom and effectively blocks the water’s access to the lower third or even 40 percent of the open hatchway’s space.  Its only drawback is having to step over it like one has to on just about every other seagoing yacht anyway.

  My first design for this involved a really cool folded-aluminum bracket that spanned the after end of the proposed bridge deck with legs down the sides of the cockpit pan to take the shear load of the traveler.  A gusset plate welded across the after side made it stiff and gave a place to mount the compass and engine-start switch.  I cut a plywood template and fitted it into the three-dimensional wedged space till I could screw it to the cockpit with sheet-metal screws and get good measurements.  (Look on the picture at the hole in the side of the cockpit pan, under the after edge of the deck-- this is where the mock-up's leg was screwed.)

  But no one would weld my bracket cheaply enough.  I wanted it for 60 bucks.  (It’s just a bent piece of metal!’)  The best quote I had was over $200.  That was out.

  Then I bought some aluminum angle from McMaster-Carr and started to fabricate a bracket by myself, mainly bolting it together.  The more pieces I put together (and paid for) the less I seemed to need each one.  Then my cousin Lee said, ‘Why don’t you just ‘glass it?’

  So I did.


  Mind that it was VERY hard to fit this thing.  The cockpit seats slope upwards as they go aft and the cockpit sides slope outwards as they go forward and inwards as they go down. By the time I’d got it screwed into the only place it could go and got one layer of ‘glass and epoxy on it, I found out one corner was too low.  So I built it up with more ‘glass and ground it fair again, and it’s thicker in one corner than elsewhere.  (I won’t tell you which corner.  You'll never be able to tell when it's done.)

  The piece of teak came from the old CBC shop which, in the process of being taken-over a long time ago, built big bulky trawler yachts about as cheaply as they could be made.  One of the ‘savings’ was from buying very bendy (and fragile) ready-made panels of teak decking. The 2-inch planks, about 5/16” thick (same as we made our teak decks on C44s) are already bonded together with Thiakol, the same stuff production teak decks used to use before we at CBC (and many others) discovered black 5200.  This piece was a scrap from the trash.  I cut it in its appropriate trapezoid and bent it over the very mild, but correct, crown from seat to seat.

  Once I was happy with the fit I figured out a very annoying but structurally-sound way to screw it in place from the bottom and test-installed it.  Owing to the thickness issues with the plywood substrata it wasn’t exactly flush all the way around.  I solved this by putting masking tape over the screw holes on the bottom, running a fat bead of 5200 round the perimeter, and then setting it down with clamps.  Relying on the 5200 ‘dam’ around the edges I drilled a few little holes in the top and flooded the uneven space between the teak and the plywood with WEST epoxy, the same as I do to repair damaged deck core inside ‘glass decks.  Then I torqued up the clamps and gave it a few days.

  The result is so strong that it probably doesn’t need the metal traveler support, but I’m putting it underneath anyway, just to spare my little artistic creation from literally flying off the handle in some nasty jibe some day.  This bridge deck allows for the mounting of the traveler about 9-1/2” aft of the cabin back, which is about 9-12 inches in from the back end of the sail.  That’s good enough for only one boom bail and fiddle blocks.  The Schaefer traveler setup has double blocks with cam cleats at each end, better than the clunky setup we had on our Raider 33, Antigone, with cam cleats mounted vertically above the traveler-control blocks so that it could only be adjusted from above, not from abaft.

  The Schaefer 1-1/8" track has holes 4” on center.  If I center one hole, one on each side goes into the gap between the teak and the ‘glass.  I have to settle on two in the center, each 2” from the centerline.  That just means I have to be particular about where I cut the track.   It takes a 60” piece, which is ideal (part 42-75).

  Along the gaps beside the teak deck will be lines of black 5200 which will resemble the Thiakol.  Amazingly-- for clearly there was some divine intervention-- I got the slivers of the outer planks more or less even and the central plank on center.  How that happened I don’t know, so don't thank me.

  The waterstains are from a leak in the aging cover.  They will sand out and I am not concerned at this point.  Eventually this teak will go silver in the tropical sun-- which is what it's supposed to do.

   So now I may have the only original-series Hunter 25 with a teak deck (ha!).

   I had intended to put the compass on a ‘dashboard’ underneath this but my neck is bad enough from using a computer already and you never want to take your eyes too far from the way ahead to steer compass courses.  I have two compasses, one from this boat and one from a wreck, and I will mount one on each side in the back of the cabin.  The current hole on the port side won’t used as it is balanced with two holes for wind gauges to starboard; so the starboard compass will be mounted below them, rather low on the bulkhead, and the other one in the corresponding place to port.

  The wood behind the hole is the epoxied back of the teak plywood laminated to the inside of the cabin top.

  The photo shows the top of the patch I made over the old deep hatch opening.  Having planned this bridge deck from the start I left the teak plywood on the inside all the way up (it was once much higher than this) and so was able to lay up half a dozen layers of mat and cloth with WEST epoxy (much of which dribbled into the cockpit pan-- see the brownish staining-- and created an increased fillet along the forward edge).  It isn’t a perfectly-smooth layup because it doesn’t have to be; only the beer cooler and cockpit bucket ever have to see it under there (though it will get more or less faired just the same before Perfection).  Above the teak it matters because a mahogany block with a white-ash threshhold gets fitted to it; and after that I can establish and install the hatch-slider boards.

  Since this picture I have cut out the bottom and sides of this hole and dry-fitted the ash threshold and the mahogany under it.  At finished height it's only about 2-1/4" above the deck now.

  The black Plexiglass deadlight admits light to the quarter berth.  As of this photo it's only dry-fitted.

  The thing along the side that looks like teak Formica is the original cabin table which isn’t going to be reused because:
  1. it’s teak (or pretending to be);
  2. it does not fit to the bulkhead and new compression post as I would like it to;
  3. it weighs about 850 pounds.
  I just never seem to throw out any part until I am absolutely sure I won’t ever need it again. I saved the original weatherbeaten hatch boards too and just recently figured out how I can reuse them on this new opening.

  The can of Bio Blast came from a WM closeout.  I like it but it doesn’t work as well as StripEaze does.  I’d much rather be bio-friendly but there is such a thing as getting the job done; and this job desperately needs to be done.

  Down below can be seen the grab-post and the top of the bulkhead I added between the saloon berth and the quarter berth.  Above the quarter berth is the cabinet for the VHF and the wallets-and-sunglasses compartment (here stuffed with clean shop towels).

  There is another picture somewhere of the head compartment forward.

  As I have mentioned before, all the of the trim wood on this boat, beyond the ash threshold, the teak plywood of the cabin bulkhead, and this bit of real teak decking, is mahogany.  None of this teak will be finished with anything; but the ash will be saturated (as well as ash can ever be) with WEST epoxy and given about 19 coats of Captain’s Varnish for good measure. Much of the mahogany came from remodelling old C44s.  Also I consider it a much prettier wood; and of course whatever I got from old C44s is REAL Honduras, not what you
get now, rosier and deeper and more beautiful.  And I am amused to think it’s almost as old as Diana is; so that’s fitting

* * *

No comments:

Post a Comment