Jack Holt Heron re-imagined Pt.1

Discussion in 'Wooden Boat Building and Restoration' started by seasquirt, Feb 14, 2022.

  1. seasquirt
    Joined: Dec 2015
    Posts: 120
    Likes: 54, Points: 28, Legacy Rep: 10
    Location: South Australia

    seasquirt Senior Member

    h E R O n

    In the beginning there were waters, and I wasn't on them.

    I love the Heron dinghy, and have sailed them on and off for over 55 years now, and have owned several, all plywood.
    Years ago when I registered a heron for an outboard motor in South Australia, it was just a bit too long for the cheaper dinghy sized boat rego., by less than an inch, and it cost me as much as a huge V8 ski boat to register with a 2 horsepower outboard - not impressed. I wanted a slightly shorter Heron.
    Many years and boats later, I read about the "Around In 10" race around the world in 10 foot long boats, (which was never started), and I thought crazy thoughts. Why not get a damaged Heron dinghy that needs work, and make it 10' long. But not sail it around the world, just around my back yard. While I'm at it, try to throw in every other idea I can manage, for fun, safe, coastal sailing, on a budget. (I laugh.)

    This was a long term project, squeezed in between a busy schedule, in no hurry, with time to think and enjoy, and change my mind on things. The new objective being to make a tough strong boat ready for anything, able to self steer, able to change sails and reef at sea relatively easily, ride out a moderate storm, surf waves, carry camping gear, and possibly a compact passenger, and be easily single handed in any conditions within reason; cyclones, hurricanes, and tornados could be a bit tricky, but do-able short term.

    The following is a mostly chronological account of a lean racing machine being converted to a tough, heavy, open dinghy micro-cruiser, or whatever category it fits into. I'm no expert.

    Wednesday 10 / 10 / 2018
    I purchased a Heron hull number 9564 for $300.00 AUS. and it was delivered in a cradle, on a basic trailer, a bare partly sanded plywood hull with some damage and some repairs made. Most screws and nails had been removed and replaced with resined in wooden skewers as pegs; I hope they hold. Someone had started to sand the interior, and gave up. Also delivered were masts, spars, rudders, and loads of boat related bits, many custom made, and not all dinghy sized. The seller wanted to be rid of all boat stuff; thank you very much, I'll take it all.
    I had a very close inspection of the hull, and measure the boat up for disection, and start scheming and dreaming, and making notes on paper for future consideration.

    CUT THE BOW:
    Removed all decking to see everything, and binned it. It was thin, old, and damaged in most places. Sanded back the stem to see the edge of the plywood let into the stem, and marked a cut line 3/4" back, ready to remove the stem complete and undamaged. Marked the bow deck centre support wood down the centre in inches (or cm) rearward from the bow tip, and held something straight in the desired new bow angle, and noted the inches to cut at the deck, minus the width of ply let into the sides of the stem. Marked where the new bow stem position will be, and any other alignment marks needed before the bow springs apart. Lifted the centreline deck support up a bit, while not disturbing it, as it is a longitudinal reference datum line/point. Cut the stem out, and then cut a wedge shape from both sides of the plywood bow at the previously made angled marks, almost vertical, ensuring evenness both sides.

    I cut the bow 7" rearward at the deck, initially giving too much negative rake at the stem, so then cut an inch further back at the hog / keel, and the bow was now going to be vertical, but still with a curved Heron stem. The stem piece was stripped, cleaned up and evened up for re-use. Check the vertical angle of the bow and trim it a bit more to easily re-fit the stem in place. Chisel sockets in the stem's back to accept the cut off horizontal hull framing ends.

    1 Front comes off.jpg
    Photo 1: Front comes off. The stem's lower gusset is still in place, as is the original bulkhead, with access hole seen. The top threaded rod isn't in place yet, and lower threads just started. The front lower transverse frame is visible; it cracked under stress.

    2 New bow angle.jpg
    Photo 2: Approximate new bow angle without the radiused stem. Large wood blocks spread the load.

    BENDING THE BOW:
    Remove the transverse hull frames from the bow buoyancy tank if able easily (or they will probably crack anyway), and all the transverse deck support frames, leaving the centreline deck support with marks on it (lifted up a bit out of the way), so all of the bow can flex unhindered right back to the bulkhead frame of the foreward buoyancy tank.
    At 75mm away rearward from the newly cut bow edge of plywood, drill 3 horizontal hole sets for transverse threadbars spaced down the bow through the frame ends, to draw the sides together with, at deck gunnel level, side frame stringer, and chine frame stringer levels. The holes must be greatly slotted like a chiasm or X or V, horizontally through the wood frames, to accomodate changes of angle of the bow relative to the threadbar, as the bow is drawn together. The threadbar must not be allowed to stress the wood angularly, and also must not bend in stress after the hull sides are done up a long way to their final position.
    Note: For the deck, make a line paralell to the new front plywood edge, but 1" astern or more, to drill for the deck threadbar, so it is just behind the stem's top back, at deck level when drawing the bow sides together. If the threadbar is more foreward, it's in the way, and the stem can't be fitted.

    3 Bolts draw in sides.jpg
    Photo 3: Pulling the bow sides together unevenly. The stem will straighten it up eventually. The top threadbar is drawing in the deckline.

    Use 8mm diam. stainless threadbar, strong wooden bearing blocks with widely angled X or V slotted holes, as above, large metal washers, and plain nuts to begin pulling the sides in to the new more vertical bow shape position. Leave for a few days and then wind in some more until stress can be heard in the wood. No moisture, steam, or heat used, just bone dry keel, hog, and plywood, bending slowly.
    Use lubricant on the threads, and wind in until hearing wood fibres starting to crack, then leave it several days, to de-stress, before giving a few more turns. Scraping varnish and paint off here and there with a razor sharp chisel, while waiting patiently to very slowly close off the stem in its new position.

    4 stem is replaced.jpg
    Photo 4: The stem held at the original bow angle, showing the cutout.

    I took bending the bow too quickly, too far, taking it past where it needed, in trying to reduce the spring apart type pressure on the nails and screws to be finally used. One night I heard a noise outside, and on investigation saw that the hog and keel had split from the stem cut, right back to the centrecase. Darn and +#@&* ! At least it was a bit more de-stressed now. The bow end had a 3/4 " wide split at the widest, and it was still together but split at the centrecase end. Luckily the boat's builder used good mostly straight grained wood for the keel and hog, and the split didn't wander much or get very messy; it split almost in a straight line down the centre fore and aft, and vertically straight through the hog and keel together. Could have been much worse.

    5 Keel and hog stiched.jpg
    Photo 5: The unfortunate event had to be stitched up. The split wasn't exactly even all the way underneath, but nothing popped completely out at the side.

    6 Splits and gaps.jpg
    Photo 6: Internal stitches, and the stem in place. Notice the splits in the wood frame pieces, and the gaps to be filled.

    From the stem area and back to the mast support post, I used copper wire ties and epoxy and fibreglass roving to stich and glue and fill the gap between the two halves, not pulled back together (impossible), but to keep them from separating more, or leaking, all done after the stem was fitted in place, so it could all be glued together with epoxy at the same time. The stem was final screwed into the plywood sides with resin in screw holes and everywhere useful. The resin was trimmed up with a sharp knife when almost hard. Next, the stem's outside joint lines were sealed up with masking tape, and the hull was stood on its bow and leaned into trees so the the stem's back was perfectly horizontal, and it was then flooded with epoxy resin from the back side, to fill all fitting gaps for a perfect bond and seal top to bottom. The keel split roving had the same flooding resin treatment, on both inside and outside, making small dams with masking tape, then grinding down the lumps to shape.

    7 New bow.jpg
    Photo 7: New profile, with resin setting, jack holding the keel up hard.

    All holes, dings, and imperfections on the outside of the the hull at the bow were filled with epoxy mixed with tough filler powder, and roughly shaped. Then after a few weeks to cure and settle, the top threabar was gingerly removed, without the hull popping outward, and the other two threadbars had thread lock goo applied, tightened a touch more, and left in place but trimmed at the ends. The lower one locked with lock nuts, ground rounded the ends close, and sealed over with a small bulge of epoxy resin and filler encapsulating the nuts. The upper threadbar left a little longer length, and used to secure the bowsprit braces with double nuts. Then the bow was cleaned up, sanded, touched up with resin and filler to its final shape, and final sanded. The new bow looks like the shape of a curved axehead, riding on, and slicing through the waves. It all looks like a classic old small dinghy. Very nice so far.

    The centrecase / hull jointing was inspected and found to be still firm, and was scraped out a bit, checked for rot - all good, firm, and secure, and the centrecase interior was then filed, scraped, and sanded, and all was then painted and sealed with epoxy resin inside the slot and at the keel, for watertight confidence. The centreboard pivot hole was in good shape and only needed re-sealing the plywood.

    The rear keel was deepened by about 19-20 mm, the thickness of a very tough plank of wood off a transport pallet; and it was lengthened foreward to the centrecase slot. The plank was glued and screwed on, sides trimmed to the profile when resin is hard, then covered with thick fibreglass mat, shaped and blended to the hull.

    CUT THE STERN:
    Now that the bow shape was finalised, I just needed to cut and finish the stern to a 10' length or less, and it's done, easy.
    Used the existing transom still in place to set the new transom angles paralell, I marked it up for just under 10' long at the deck, and drilled a thousand 2mm holes along the marked lines, to guide the hand wood saw from wandering. The transom frame was sawn off very close as a slice, then the remaining 7 inches was completely cut off, including the attached keel section.

    8 Slice off transom.jpg
    Photo 8: Cutting the transom frame slice off. Many small holes help guide the saw. Notice the wood skewers glued into screw and nail holes, and cut off flush.

    9 Section to be removed.jpg
    Photo 9: The section of rear buoyancy tank to be removed after the transom is gone, gauged via the inner deck supports, and the line of small holes barely seen.

    The transom frame slice including the plywood side remnants, bottoms strips, plugs, nails and screws all still in place, was cleaned up ready for epoxy. The old transom is smaller than the new stern shape, so good solid wood packing was found, glued and fixed to the bottom and side edges of the transom slice, and made symmetrical. The now enlarged transom was then closely fitted into the new bigger stern gap, glued and screwed in place, making a new square stern (it was a bit out of square before), edges and corners trimmed square-ish, and voila - a 10 foot long boat which looks good, like it was "meant to be". A piece of 6mm ply was first epoxy sealed both sides, then glued and screwed vertically right across the back, covering and sealing the transom buildup with no blemishes, and it was trimmed to the final hull shape once the epoxy had cured. About 8" was cut from the stern, and from the bow, to get a 10' long hull. The rear buoyancy tank is now quite narrow.

    10 Packed out transom.jpg Photo 10: Old transom is new transom, with a bit of packing to fill the gaps. The keel has been deepened by ~20mm.

    11 Ten feet long hull.jpg
    Photo 11: Shorter hull shape, still looks good and proportionate, like it was designed that way.

    A reinforcing web of 10mm thick plywood was fitted in the rear buoyancy tank, vertical on the centreline from inner tank wall to outer tank wall, with a gap at the bottom for inspection and sponging out water. This panel is to help carry the twisting hanging load of the central outboard motor bracket, to be fitted later. Twin rudders will be used.

    The hull's well worn plywood bottom was transversely split across on both sides, at the beam cross floor frames, where it typically bumps and grinds and rests on beaches and hard boat ramps. The chine and keel ends of the split were still good plywood, so fibreglass roving pads were epoxied on both P and S sides, inside and outside, to patch and reinforce the problem area. I have seen it split there before on other Herons, so not unusual on an oldie. Filled gaps, holes, and big dings along the hull chines and stern, prepare and sand, and then epoxy 50mm wide woven fibreglass tape along all outside hull chine edges and other corners, to protect the old wooden corners and edges.

    Go over the hull filling small hollows and blemishes with epoxy filler. Trim it all and sand it all for smooth blended shapes and edges, and go over it again with more filler in hollows. Mix large batches of Bote Cote epoxy resin and TPRDA wetter agent, and epoxy resin the entire hull outside with a large paint brush, to soak in and seal the old plywood, give extra surface strength, and to prime the hull ready for more resin where needed, and then paint. I see some more imperfections now its sealed, and fill and touch them up, to smooth the keel and hull shapes for smooth water flow.

    Fit the original stem backing gusset to the new bow profile, screw and fibreglass it in place. Fill in all remaining splits in the front interior framing and woodwork, damaged by the forced bow bending effort. Some framing was split but not broken apart, and it was resin filled and re attached.
    Bow front frames were re-shaped and re-positioned, new wood added as reinforcement for sideways pressures below, and a new shorter under deck support transverse piece made for the frame. The old top piece was placed rearward where it's wider, to add shape and strength to the foredeck.

    The old front buoyancy tank plywood bulkhead panel was cut out, leaving its frames still in place. I marked up the new position of the front of the cockpit / front buoyancy tank bulkhead wall further forward, 7 feet from the rear buoyancy tank, so anyone will be able to lie down stretched out on the floor.

    Made new frames for the new bulkhead at 6' 10" from the rear buoyancy tank, the loss of 2" for much greater front buoyancy tank volume, was a safety consideration tradeoff. And I'm not 7' tall anyway, so no big deal.
    A strong tow ring was inserted in the bow and epoxy sealed, for towing and trailering attachment, tightened against the back of the stem, and also against the two lower transverse threadbars, with a vertical stainless steel load spreading bracket used. If the tow ring pulls out, so does the entire stem and bow.

    RAISE THE DECKS:
    Sawed up 12mm x 15mm pine wood strips, and layer it around the gunnel top edge and over the deck supports, to make it all 30mm wider at the deck, 24mm higher over the cockpit wall of the rear buoyancy tank, and 36mm higher over the front deck, making a low forecastle, and a little bit higher along the side decks to line up with the new stern deck profile. Added 36mm higher to the front of the cockpit transverse deck support and mast support area. Shape the new deck profiles by eye with an electric plane freehand until it looks good, and even both sides. The stem piece is finally trimmed shorter at the top, now level with the deck supports. The change of bow angle made it sit taller than originally designed.
    I wanted the rear deck to angle down rearward slightly, so rain and spray didn't naturally pool or run inboard, and for the foredeck to align with the rear deck for nice asthetic lines, that's why the step or height change exists at the foredeck / side deck join. Purely for overall looks, no other reason; the uneven deck detail is often not even noticed when an overall view is taken. Building up and blending and feathering the decks to all meet would have been lots of extra work, adding weight, and may have turned out badly, so I just left it. The step is beneficial in the end, when I make a cabin. Yes, a cabin.
    When the bow was stressed inward permanently, the entire boat flexed and changed shape a bit, being flexible wood, so the extra wood strips and raised decking is also helping to stabilise and hold the new hull topside shape. As will the new deck panels.

    12 Reinforced raised deck.jpg
    Photo 12: Edges widened, decks raised but not shaped, new front buoyancy tank bulkhead installed, rear air tank finished and painted inside. White epoxy filler filling gaps and bedding the central deck support beam, to be fitted later.

    NEW FRONT BULKHEAD:
    Made the new front buoyancy tank bulkhead panel of 6mm plywood, epoxy sealed it both sides, and set it aside to harden. Align, fit and glue the inside bulkhead frame pieces to the hull in final position and let harden for a day or two undisturbed. Then screw and glue the new front bulkhead panel in place, and screw the pre shaped cockpit side frame pieces in place while all edges and corners are epoxied, for a watertight seal on the bottom and sides. The missing foredeck top panel will seal the top of the front air tank later on. Screw in and seal an inspection / access hole base, and lid. The boat is now smaller on the outside LOA 3.429 m (11.25 ft) cut down to 10', and it is longer on the inside by 6 - 7 inches. (Less sealed buoyancy, but hopefully still enough flotation.)

    13 New bulkhead.jpg Photo 13: New bulkhead in place, old one cut out, foreward seating cut away, decks raised. Patches on the floor near centre cover automatic bailer holes both sides. A big battery and 2 old rubbish 12V battery drills on 12V power leads, one for drilling pilot holes, and the other for countersinking or driving screws, makes for faster production line screwing.

    Made a sturdy support for under the centre of the rear seat, glued, and screwed in place, and filleted.

    Both bow and stern buoyancy tanks are tidied up inside, removing splinters and spikes, making them smooth and safe for hands, all inside corners were filleted, then tidied up again when nearly hard, rough sanded, vacumed out clean and painted everywhere inside both buoyancy tanks with white enamel paint, to seal all fibreglass work and new bare deck support wood, and lighten the areas for visual inspections.

    End of 2018

    Rudder pins get fitted on new transom, as high up and wide apart as possible, vertically as near as parallel as possible, but biased bottom outward if not exactly parallel, and then the hinge pin brackets were removed for more hull preparation and paint.

    With the hull upside down on the trailer, I climbed inside under the hull, and scraped bare every inch of wood and every corner around all woodwork inside the cockpit area, of all glue, varnish, and paint, with a range of razor sharp chisels, so it's all thoroughly inspected, and very clean and dry, ready for more woowdork, resin work, and later, varnish and paint. This took months of tedious scraping, bit by bit after work, when I felt like it. The hull outside is now sealed with two resin coats, sanded smooth, and first coats of yellow marine paint applied to bottom and sides while it's upside down.

    Turned it over back up the right way again, make and fit two longitudinal stringers between the front and rear buoyancy tanks, up hard against both sides of the centreboard case, to raise the floor boards at the centreline by about a couple of inches. Then raise the existing bottom frames to the same height, to support a new higher, more level floor angle. Not a flat floor though, just less angled by about 10 degrees each side, and centrally raised.

    Make and fit extra transverse intermediate floor supports / bottom frames under the rear cockpit floor, and forward cockpit, in between the original frames, to strengthen and stiffen the hull toward the bow and stern, support the floors at their new angles, and buttress against the centrecase's lower sides.

    14 Extra frames.jpg
    Photo 14: Rear buoyancy tank is clean, central stringers added, extra floor supports added, floor angle changed, extra seat supports, centrecase seat support wedge added, all floor related corners are filleted, rollock blocks fitted to decks.

    A wood wedge was made and fitted with screws not glued, to stay on the rear of the centrecase, and help support a removeable horizontal rowing seat made of plywood, positioned near the beam. The outer edges of the seat are supported by the hull frames, and old seat remnants.

    Looks like I didn't do much this year, but it was a lot of work scraping out all of the interior coatings like a fanatic, after work and on weekends, fitting up extra major woodwork ready to glue, and finding and repairing, preparing, and assembling many small parts to be needed later on. And I did a lot of thinking too.

    End of 2019

    All floor support and lower woodwork old and new was glued, sealed, cleaned up, and filleted with epoxy and filler by gloved finger, so no corners are anywhere under floorboard level, no moisture traps, made for easy hosing out, drying out, and extra frame strength and bottom stiffness.
    When the fillets are hard and fettled, and all woodwork cleaned, the whole hull interior was final trimmed, removing sharp and pointy features, sanded roughly, and painted everywhere with cheap clear indoor varnish to seal it everywhere inside, later to be painted over with water based UV protected exterior paint, with the selected colour. (Jade)

    15 Resin and paint inside.jpg
    Photo 15: All of the interior is sealed variously with resin, varnish, and paint, end to end, top to bottom. The floor and bottom is strong and stiff. Many kilos of extra wood can be seen.

    Continued in Part 2.
     
  2. messabout
    Joined: Jan 2006
    Posts: 3,367
    Likes: 510, Points: 113, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Good on you mate. That was an ambitious modification, but you are making it work.
     
  3. Will Gilmore
    Joined: Aug 2017
    Posts: 939
    Likes: 434, Points: 63
    Location: Littleton, nh

    Will Gilmore Senior Member

    I too, am fascinated by the Around in Ten and have design ideas. I am so glad to watch someone working on a viable ten foot micro cruiser, not to sail around the world, but with that standard in mind.

    I'm excited to follow your project.
     
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