Spindrift 11N #1683 build photos/tips

[11N1683]

Hi Folks,

 

Spindrift 11N #1683 checking in from Europe. Started build in March from 5 sheets of 4mm ply.

 

Highlights:

- Laser rig (not yet fully fitted)

- 4mm ply + glass

- very lightweight

- forward seats

- great & cheap fenders.

- easy nesting bolts

 

Photos and finished weight (I keep forgetting!) to follow.

 

I wrote a bunch of tips during construction but lost (!) them during the transition to full-time liveaboard. Did my best to put them together today. They are long and rambling and available HERE Then I asked GPT to edit them and fixed that up - much more digestible and pasted below. Sorry for the bold type, view at the link if you prefer.

 

I prioritized light hull weight above pretty much everything. I also wanted to gain composites experience.

 

Many many thanks to everyone who contributed build logs/tips/videos here and elsewhere. Couldn't have done it without you.

 

Construction

 

• Materials:

  • Marine Plywood: 4mm marine ply

  • Fiberglass:

    • 200, 150, or 100gsm 2x2 twill glass everywhere except inside the aft seats, depending on requirements

    • 10cm 300gsm 45x45 glass tape inside as per plans

    • 300gsm tape on/over keel and strakes

    • 14mm aramid flat braid + 300gsm 45x45 tape on keel and strakes

    • Inside bow keel much reinforced

  • Parts

    • Knees, transom, keel/strakes, breasthook: Spruce

    • Seat cleats and gunwales: Pine/fir

    • Mast Step: Marine ply, 300gsm bearing plate

    • Foredeck: Skeletonized 4x4mm marine ply, 200gsm glass both sides

    • Mast Step Turning Block Plate: ~6 layers of 600gsm built over a simple mold to make the angle

    • Rowlocks: Meranti with 316 stainless steel pipe epoxied inside, epoxied on and screwed into the gunwales

• Assembly:

  • Tape as per plans, no tape outside except keel and strakes (see regrets)

  • Aft floor stiffened with strakes parallel to keel

  • No plywood cap on the inner transom (200gsm glass both sides)

  • Nesting bulkheads thinned and glassed

  • Cleats are minimal (e.g., 21x21 triangular section pine), relying on the glass and lightweight users

 

Fastening

 

• Screws:

  • 316 wood screws, minimal use, only for breasthooks, rowlocks, and knees

• Nesting Bolts:

  • Used 5x M6 eye bolts:

    • Top two backed by M6 eye nuts for ample torque

    • Lower three greased bolts potted with nut + washer in thickened epoxy within plastic bottle caps

    • Each bolt fitted with a large M6 washer and ~5mm O-ring to prevent leaks and keep washer captive

    • All bolts can be threaded together as a bundle for storage (inside a seat)

 

Misc

• Ties:

  • Regular galvanized steel wire preferred over zip ties for better control and smaller holes

• Rigging:

  • No padeyes; everything is potted holes with 2-6mm Dyneema threaded through

  • 2mm padeyes in all four corners of the NBKHDs for 3/4 point lifting if needed

  • Knee eyes double as traveler (whoopie sling with LFR)

  • Whoopie tail has an eye splice looped over the outboard screw as the safety line

 

Incident

 

• Accidentally dropped the plane in the bow during assembly and smashed it open along keel

• Recovered using a Spanish windlass with no harm done

 

Specific Components

 

• Gunwales:

  • Hardest part to machine

  • Required creative use of track saw and jury-rigged router table for angles

  • Lap joints worked fine, not the hard part

  • A router table and table saw would expedite the process

• Foredeck:

  • Sloped forwards to drain water through the painter (6mm dyneema) hole

  • Cleated around three sides, relying on 16mm thick plywood + glass for strength and stiffness

  • Foredeck hatch for anchor and bailer storage

  • False floor, sloped aft, with a drain bung

  • Floor serves three purposes:

1. Collision protection

2. Easily drain water/rinse out anchor mud

3. Protect the hull in case the anchor is dropped

• Fenders:

  • ~10mm rectangular rubber around the outside of the gunwales

  • Firehose cut lengthwise in half, contact cemented in place

  • Hit hard with a plastic mallet and use high-quality cement (~300g used)

• Wedges for Nesting:

  • Forward piece slightly smaller than the aft piece to allow sliding on deck

  • Fixed two wedges on the inside corners of the aft nesting bulkhead to prevent damage

• Foredeck and Seating:

  • No midships seat; daggerboard trunk just wide enough for seating

  • Rowlocks ~14.5 inches aft of the seat edge

  • Potential to add seats or carry gear/passengers in the back

 

Epoxy Tips

 

• Resources:

  • Explorecomposites (site) and Easycomposites (youtube) for good insights

• Application:

  • Wash all epoxy before sanding unless peel ply was used

  • Use peel-ply on areas that are not tortured nor have sharp radii

  • Cut green epoxy with a razor blade instead of waiting until it dries

• Mixing Fillers:

  • Mix cotton flocks with silica and/or microballoons to minimise dust (AMAZING!)

  • Glue: 1 silica : 2 cotton @ <15% w/w

  • Fillets and Filler: 25 microballoons : 5 silica (optional, to prevent runs) : 5 cotton @ <30% w/w

  • Fillers are economical, reduce weight, and dramatically decrease resin usage ($$$)

• Pigments:

  • Use pigments in resin for easier identification of drips, new glass, and mixed resin

  • Example: Purple for glue, white for fillets, green/blue/yellow for resin

• Fillet Application:

  • Use freezer bags instead of icing bags:

• Place a 200ml paper cup inside a freezer bag

• Add fillers by weight and a drop of pigment

• Mix resin in a separate 100ml cup for reuse

• Add resin to the bag, close and knot with minimal airspace, knead together, and nip a corner for a perfect fillet bag

• Silicone spatula set preferred over sticks for fillets

• Additional Tips:

  • Clean with acetone after using debulking rollers; store acetone in a large HDPE container with an airtight lid

  • Invest €40 in a proper respirator and store it in a gallon ziplock when not in use

  • Dry used cups and mixing sticks on peel ply for reuse

  • Poor Man's Prepreg:

    • Use lightweight painter’s plastic (e.g., Tesa with masking tape on one side)

    • Lay out larger sheets than the glass size

    • Dribble resin on glass, add another plastic sheet on top

    • Use a plastic squeegee with masking tape to wet out the glass completely

    • For complex layups, use slow resin and freeze sheets before cutting

    • Reference: DIY Prepreg Video

  • Use slip joints on inside corners, esp if vacuum bagging

  • Apply a little thickened epoxy to outside corners before glassing to prevent voids

  • Avoid using 3x epoxy; use 100gsm glass for faster, neater, stiffer results with the same weight

 

Best Tools

 

• Dust collection! I used a karcher shopvac

• Shinto rasp (I feel like a sinner but it's great)

• Router with roundover, pattern, and plunge bits

• Track saw (table saw preferred if space allows) for cutting plywood

• Lofted, cut, and built on OSB sheets with IKEA sawhorses, hot-glued, screwed, and levelled in place

• Permagrit block

• Jack plane (consider adding a block plane)

• Pull saw

• 150mm sander with soft pad, Abranet discs (pay for themselves)

• Oscillating multitool with Permagrit (tile/carbide) blade for glass

• Jigsaw

• Hole saws

• Good cordless drill

• Makita 9031 band file

• Angle grinder (if space allows for making a big mess)

 

Performance and Usage

 

• Steering and Control:

  • Bangkirai outboard pads fit a Suzuki DT2.2 perfectly, compatible with standard Laser rudder gudgeons

  • Minor binding due to Laser transom rake, not problematic

  • Laser rudder+head+gudgeons

• Speed:

  • 7 knots in flatish water with 2.2hp motor, two people (110kgs), and minimal gear

  • 5.5 knots at half throttle

• Dryness and Handling:

  • Pretty dry even in good chop; gunwales and flare perform well

  • Slightly increased forward freeboard from plans

 

Plans Feedback

 

• Keel Lines:

  • Difficulty fairing keel lines at the bow on metric plans

  • Ended up using imperial plan measurements, not realising stations were different, resulting in a shallower forefoot than intended

  • Required some trimming on FDK and FBKHD

• Aft Seat Sections:

  • Metric plan lines for aft seat vertical sections confusing regarding inside vs. outside ply edges where they meet the hull

• Dimensions:

  • Single dimension per point in main plans; extra dimensions for alignment/checking would save a lot of tears.

• Gunwales:

  • Within reach for average builder but probably require two people and create a mess

  • Suggest simplifying assembly procedure if possible

  • If I did it again, would do one layer at a time and use mostly screws + ply pads

• Forward Seats:

  • Recommend adding forward seats to plans for easier construction

    • DIY with a joggle board and level was awful

    • Critical for enough floatation/collision protection when sailing/motoring in open waters without support

    • Inspired by other posters' pictures and much indebted

 

Future Projects

 

• Oar Rack:

  • Ocean South heavy-duty 215mm aluminium 2-part, fits perfectly alongside forward seats and rudder

• Stern Seat:

  • Tricky to row with someone on one side; ideal to have a drop-in seat well forward

• Daggerboard Trunk Cap:

  • Gasket using sealant + plastic wrap release film

  • Essential for sealing

• Rig:

  • Currently have a full Laser rig lashed to the toerail in a bag

  • Scored a Laser rig, rudder, sail, and board for €200

  • Plans to chop the bottom off the mast sleeve and add halyard and clew webbing eye for reefing

 

Regrets

 

• Daggerboard Trunk:

  • Should have fully boxed the trunk for alignment during assembly

  • Protrusion on aft piece and vertical slot in trunk/NBKHD like the Chameleon

  • Neodymium magnets were ineffective

• Foredeck Reinforcement:

  • Should have used more glass on the foredeck (e.g., 2x200gsm, 10mm foam, 4mm ply, 3x200gsm)

  • Foredeck gets abused when living on deck

• Foam Usage:

  • Should have used more foam or foam + plywood in areas like foredeck, seats, and bulkheads

• Keel Extension:

  • Should have extended the keel or Kevlar tape further forward to prevent damage, forefoot gets abused

• Bolt Strength:

  • If lower, center bolt was stronger, could have used the eye to fix a mainsheet turning block

  • Considering adding a second bolt or padeye with more substantial reinforcement

• Additional Glassing:

  • More glass needed in high-abuse areas: NBKHD upper corners, top of gunwales, aft seat edges, forefoot of keel, foredeck

  • 300gsm tape sufficient, but open weave adds unnecessary epoxy weight

• Paint:

  • 2-pack paint was too stinky, difficult to work with, and slow to drycompletely

  • Recommend using 1-pack paint with a common color (e.g., 9003) for easier matching and repairs

  • Prefer painting just the outside before leaving on our trip for easier repairs and reinforcements

• Workspace:

  • Built 80% in a spare bedroom and laundry

  • Asked boatyard to rent space in shed: "sure, no charge" - would have been way faster earlier.

  • Climate-controlled space is critical, especially when working with epoxy

 

Alternative Designs

 

• Chameleon:

  • Small, overbuilt, insufficient freeboard

• Pt11:

  • Expensive, no plans, elegant nesting, kit not shipping to EU

• Fb11:

  • Pram bow, no enclosed seats, limited information

• Stasha Skin on Frame:

  • Not suitable for foredeck abuse, tough to clean

• Mebo 12:

  • Mebo 12 Design

  • Very close to our design goals, few built, possibly too big for some decks

• Goat Island Skiff:

  • Not nesting

• OK Dinghy:

  • Nice lines

• Cherub:

  • Good for design/construction inspiration.

 

Closing Thoughts

 

• Overall Experience:

  • Fantastic boat; highly satisfying to build and use a great dinghy

  • First day motoring around to a sunny beach was magical

• Cost and Time:

  • More expensive and time-consuming than anticipated

  • Choice of glass + vacuum bagging increased complexity and duration

  • Experienced builders could complete faster

  • Timeline: Started in March, launched painted in July while refitting the big boat

• Construction Insights:

  • 4mm ply + glass is doable and lighter, but requires good understanding of forces, stiffness, and strength

  • Necessary to calculate/test Young’s Modulus for different orientations and weights

  • Not cheaper or easier without proper knowledge or designer assistance

 

 

[11N1683]

Here are lots and lots of photos. I swear I uploaded them in order but the forum software had different ideas. Still, they are approximately correct.

 

 

[Bryan Rolfe]

Excellent build, thanks for sharing!

You really went above in beyond, doing some vacuum bagging and foam construction. I also noticed you glassed the inside of the boat and I'm wondering if I'm going to eventually regret not doing that on ours, as I suspect over time we'll drop things in the boat and glass would offer some impact resistance. However, it's already pretty heavy as it is, and I don't know which trade off I would have ultimately preferred.

What is the material you used for your rub rail?

[11N1683]

Thanks for the nice words Bryan.

 

1) 100gsm glass inside probably doesn't weigh more than epoxy, but in my case I chose to use 4mm ply so the glass is critical 

2) rub rail is ~12mm stick on foam weather seal all round, covered with a half section of fire hose, applied with contact cement. Sorry, I DEFINITELY meant to put that in the original thread, it's absolutely one of the highlights of the build. I paid 20€ for 17m of retired hose (size is C-hose in Europe). I split this, discarding the folds, with a pair of tin snips.

[Aphers]

Great posts, thanks for sharing.

What was your finished weight? 

And how are you getting those kinds of speeds from a 2.2hp?? I can get to about 6.5kt with my 3.5hp... I've done over 7kt, but only under sail.

[11N1683]

Weight I unfortunately still don't know. Will try to remember to get the scale on it next time I move it.

 

Speed... Just a rough estimate from Navionics on the phone. If I had to guess, neither we nor the boat weigh much. Could also have been a bit of current or wind. I'll try to measure again next time I use the motor (probably awhile now as we're in sailing mode with the laser rig!)

[Alan Stewart]

Excellent pictures and writeup on this. Graham and I were looking closely at this build for what will soon be the S11 Nesting V2 and have been thinking that it should just be 4mm ply so we're also very interested in what your finished weight was (bare hull without rudder, cb and mast/sail).