Building a DN ice boat

Building a DN ice boat

DN ice boat in shop
DN ice boat in shop

Building the Hull

Materials for hull
Side boards
Building Hull
Finishing hull

Building the Plank

Materials for plank
Building Plank

Insert Runners

Materials list per runner
Tools Needed
Material Preparation
Material Assembly
Finishing Steps

Building the Hull

by Allan Dake

Materials for hull

  • (2) side boards 1″ X 8″ X 14′ (Sitka Spruce preferred) planed to 11/16″
  • (1) Spruce board 1″ X 8″ X 8′ {bulkheads etc.}
  • (2) 4′ X 8′ X 1/8″ Mahogany marine plywood – decks and bottom
  • (1) 1″ X 3″ X 12’3″ basswood – center stringer for bottom
  • metal parts for boat order from Sarns: runners, steering parts, plank attachment parts, mast step, fore stay attachment bracket, bob stay parts
  • one gallon West System epoxy, hardener and appropriate pumps
  • wax paper, stir sticks and plastic mixing containers
  • West 404 & 406 filler
  • (1) 4’X8’X3/4″ blue Styrofoam creates stiffness between cockpit floor and bottom
  • obtain jigs to make curves in side boards and jig for bow

Side Boards

  • plane side boards to 11/16 (sand to 5/8 later)
  • side boards should be about 12″ 6″ + to end up with a boat 12′ 3″.
  • using Official specifications, layout heights desired on one side board
  • use 13′ long flexible batten to get continuous curve for the top of the sides.
  • Recommended heights at stations; (0) 3-31/4″, (1) 4-1/2″, (2) 5-7/16″ , (3) 6-1/8″, (4) 6-5/8″, (5) 7″, (6) 7-1/16″, (7) 7″, (8) 6-5/8″, (9) 5-7/8 ” , (10) 5″, (11) 3-7/48″, (12) 2-5/8″, (13) 2-1/4″ these will vary slightly
  • at station 4 where steering (tiller) post is, should be less than 6 3/4″ to work with Sarns standard steering post. Sarns will build a long post if desired. Check dimensions of post and head and remember 1/8 plywood for deck and bottom
  • cut out side and leave line to be sanded down latter
  • lay cutout side board on second board mark and cut
  • mark top of side boards into thirds (two marks) in stern area about 32 inches long
  • cut 2 slots in both side boards on band saw with 1/2″ blade. recommend 6 teeth per inch to clean out saw cut, using a tall fence and cut slowly use finger guide to hold against fence!
DN iceboat build sides
Cutting slot in sides
  • trial fit side board in jig before gluing!!!
  • use plenty of epoxy a hack saw blade will assist in tight areas
  • pull the bends into jig slowly and be sure all three cut pieces line up at top and bottom before tightening them down
  • dry in jig for at least 24 hours
DN iceboat build sides in jig
Sides in the jig



  • set side boards in bow jig, tighten against jig, check bottoms for level (be sure you have wax paper down so drips do not stick). If you wish a narrower entry or width of bow make adjustments here.
  • cut bottom center board (11/16″ X 2 1/2 X 12’3″), to fit bow and stern widths as desired
  • cut slot in bottom board in rear area about 26″ in from end. This is for 1/8″ plywood for fore and aft bulkhead stiffener behind seat under deck.
  • forward bulkhead location dimensions should be (1) 54 1/42″, (2) 41 5/8″ (3) from bow approximately
  • cut bulk heads with angled sides for (1) front of cockpit, (2) under mast step, (3) between mast step and bow these should be from 11/16″ Sitka left over from side boards.
  • you will need to cut bulkheads ( 1 & 2) to fit bottom board and top board between bulkheads (1) and (2) for mast step to sit on be sure it is long enough for front of mast adjuster to screw into.
  • make bow block from Sitka or pine at least 8 inches long
  • cut out bow block to fit angles
  • cut out stern blocks one on each side of bottom center board top & bottom
  • glue all of the above in with epoxy, check alignment fore and aft as well as vertical!!! {This set up determines whole boat alignment}

DM ice boat build frame in jig    2 boats one in jig   basic frame

  • cut 11/16″ x 2 1/2″ by 16″ Sitka for Mast Step top of box
  • cut 1/8″ plywood to fit each side of mast step box
  • cut Sitka pieces to fit inside of mast step box – two in middle 11/16″ and one at each end to glue plywood too these should be 3/8″ and glued to bulkheads
  • epoxy inside of pieces in mast step box glue all sides then epoxy the rest of the box and plywood sides
  • cut pieces for seat bulkhead 1″ X 11/16″
  • front of seat will be about 60″ aft of forward cockpit bulkhead or no more than 110″ from forward steering post
  • seat angle should be 36 degrees
  • glue in seat bulkhead pieces check for square to boat
  • cut top stringer board for back deck support, needs slot for 1/8″ plywood vertical fore and aft stiffener
  • epoxy in above plywood and top piece
  • mark and cut out cockpit floor
  • check for fit and then cover with fiberglass if desired.
  • when floor is dry install on floor stringers (installed below)
  • cut pieces from Sitka for cockpit floor to rest on, as well as plank attachment blocks
  • epoxy in above pieces
  • epoxy inside of sides behind seat bulkhead and in front of cockpit forward bulkhead
  • fillet all areas on both sides of all bulkheads except inside cockpit (epoxy with 404 mixed to consistency of peanut butter) use large stirring stick
  • route in slot to install 1″ x 3/8″x app 24″ piece from bulkhead (2) to nose piece to support deck
  • use square to check sides and top, sand as necessary
  • glue in cockpit floor
  • cut foam to fit between stringers in cockpit floor
  • epoxy foam to bottom of cockpit floor and edges
  • mark out bottom two 1/8″ plywood pieces, seam should be right on cockpit front, bulkhead this keeps it away from mast step providing more strength.
  • cut out rear and front deck 1/8″ plywood pieces and epoxy inside
  • glue top decks on
  • check glue areas and fillet in mast step area epoxy inside of deck areas
  • epoxy insides of bottom plywood
  • glue bottom plywood pieces in place
  • make knee using 2 – 1/8″ plywood and a 3/8″ piece of Sitka glued together
  • use trim router with ball bearing to trim edges of plywood, sand only as necessary
  • cut out seat back supports and glue in these pieces
  • cut out seat back use two pieces of 1/8″ plywood glued together
  • glue in seat back
  • cut out cockpit trim pieces and glue on
  • trim off cockpit trim with router, sand as necessary
  • sand all sides, decks and cockpit areas with 150 grit with palm sander
  • set knee app. 22″ aft of cockpit forward bulkhead epoxy in place
  • epoxy all surfaces, two/ three coats (use foam roller and foam brush to brush out bubbles) I recommend 207 hardener for final two coats it has UV protection and brushes out easily like varnish, less sanding

insideA_bottomJ   bow view 2nd coat epoxy

  • use Scotch Brite & water between coats and wipe with rag immediately to remove Amine Blush (wax like looking coating over the hardened epoxy this is very important)
  • drill holes for steering and all fittings, steering hole should be about 6 1/4″ from nose which will fit in rear hole (slot) of Sarns stem fitting
  • fillet cockpit areas use popsicle stick and then chisel to clean near fillets

Finishing hull

  • sand all surfaces smooth for varnishing (this smoothness is critical)
  • varnish all surfaces with three coats (marine spar with UV protection)
  • mount hardware
  • Mast step 40 7/8″ + 1/8 – 5 7/8″
  • Steering 46″ + 4″ – 2″
  • Bob stay fasten rear at 8′ 4″ approximately
  • Plank attachment 104 1/2″ to 116″
  • Bob stay post install in middle of mast step structure.


Building the Plank

by Allan Dake

Materials for Plank

  • (2) pieces of ash 5/16″x8″x8′ 3″ you may need to purchase 1″ piece and resaw to 7/16″
  • (1) piece of Redwood or Basswood 1/2″x8″x8’3″
  • one quart of West System glue

Building the Plank

  • Thickness Max 1 5/8″ Min 1 1/8″
  • Width Max 7 1/2″ Min 6 1/2 “
  • Length Max 96″ Min 94″
  • top & bottom 5/16′, core 11/16″ for 170 lbs person
  • cut ash in two or four pieces as desired for top and bottom of plank
  • glue edge of pieces together important keep pieces flat as you pull them together
  • plane ash from 3/8″ to 5/16″ as desired
  • spread glue on top of bottom pieces
  • glue both sides of each piece and set in jig
  • put clamps from jig in place and tighten down slowly from center toward the outside
  • use torque wrench to tighten all clamps equally, do not over tighten this will force all glue out, let sit in jig for at least 24 hours
  • remove from jig, cut to length and sand as necessary
  • If the plank comes out too stiff, then I shape it into an oval shape to streamline it somewhat. Any wood removed during shaping decreases the stiffness.
  • If the plank comes out too limber, then I remove as little material as possible during the shaping. I still do some rounding of the leading and trailing edges, but it might only be rounding over the edges with a router.
  • A glass wrap will stiffen the plank about 1/4″ (for a 180lb sailor), so allow for this when shaping the plank. If the plank ends up too soft after adding the glass, it can be stiffened by adding additional glass. The better way to stiffen the plank would be to add unidirectional glass to the bottom .
  • After a plank is shaped, you can cover it in fiberglass cloth for protection. Here is how it is wrapped (thank Ron Sherry for this method):
  • 1) Wrap the middle 4 feet of the plank, overlapping about 4″ on the bottom.
  • 2) Wrap the whole plank, overlapping about 4″ on the bottom again. Note: use 6oz or 8oz glass cloth (cheap is good).
  • coat with epoxy do not forget to remove amine blush and sand
  • Varnish two coats
  • Attach chocks and plank attachment fittings
  • Set alignment

Insert Runners

by Randy Rogoski & Allan Dake

West Michigan Ice Yacht Club October, 1997 Insert Runner Manufacturing Steps
(Dimensions according to IDNIYRA official specification EA )

Materials list per runner

  • Steel Insert Plate – Cut, shaped, drilled for reinforcement rod or wing stiffeners, hardened, running edge formed. Line drawn 1.5 inches along length from running edge.
  • Wood Body – Hard rock maple 4″ x 40″ x 1″ planed to 7/8″, cut to length, height and shaped.
  • Carbon Fiber stiffeners (2 needed) – 1/16″ thick.
  • Pre preg CarbonFiber sides available from Ron Sherry or order Woven Carbon Fiber Cloth from ISACO in Minneapolis, Mn 1800-328-4827 ext 2662 talk to Mike or U.S. Composites ask for Mark at 1-888-659-7022 in Florida.
ice boat build carbon loose
Carbon loose
  • * Order cloth needed for two runners 4″ x 40″ minimum, by the yard width is typically 50″. 19.7 oz 2X2 twill weave is .03 in thickness 5.7 oz is .01 in thckness. You need about 1/16″ for each side, which is .0625 The twill weave is slightly stronger than the plain weave. 3k means 3000 filaments per each strand
  • Threaded Stainless Steel reinforcement rod (8 needed) – 5/16″ dia x .850
  • Fiberglass Cloth – 10 oz.
  • 5/8″ Brass Bushing for pivot axle hole.
  • WEST System EPOXY, 406 filler, 423 Graphite Powder, sand paper, mold release wax, pipe cleaners, glue brushes, squeegees, scissors, poker, latex gloves, acetone, paper towels, polyethylene drop cloth.

Tools Needed

  • Insert Runner Clamping Fixture Mold with 3 one inch spacers. Clamps (8 or more needed)
  • Hammer, router, belt sander, orbital sander, plane, sandpaper.
build ice boat runner jig
Runner Jig

 Material Preparation

  • Assembly should be wiped with acetone and put ss pegs in bottle with acetone and shake them then handle carefully .
  • Steel plate – Roughen with 60 grit sandpaper, only portion of faces to be glued. Wax below center line faces to show.
  • Wood body – Cut slot in bottom per steel plate thickness. Drill holes for reinforcement rod (8 needed). Round bottom edges with plane – outside & inside of slot, make hole a little large for pins
  • Carbon fiber – Cut to size and shape same size as wood body. Apply mold release wax to outside faces.
  • Fiberglass cloth – Cut to 14″ width from roll of 38″ length cloth. Use magic marker to draw line lengthwise on center.
  • Reinforcement rod – cut to .850. Clean off dirt and grease with acetone.
  • Clamping Fixture – Clean epoxy off from last use. Apply coat of mold release wax to everything you do not want epoxy to stick to.


  • Set out epoxy, fillers, and miscellaneous supplies.
  • Double check hole alignment between steel & wood. Adjust wood if necessary.
  • Mix four pump strokes of epoxy resin & hardener for wet out.
  • Wet out materials with epoxy
  • Steel Insert Plate – Coat both sides with epoxy above center line. Sand epoxy into steel.
  • Wood Body – Use pipe cleaners to wet out inside of slot and insides of holes. Wet out faces.
  • Carbon Fiber – Wet out inside surfaces only. If using Woven cloth wet out all of material
  • Fiberglass Cloth – Wet out thoroughly.
  • Mix two pump strokes of epoxy. Thicken epoxy to mayonnaise consistency with 406 filler, about four heaping teaspoons. Use 423 Graphite Powder to turn thickened epoxy black. Use squeegee to keep thickened epoxy in a uniform ridge two inches wide down center line on fiberglass cloth.
  • Reinforcement Rod – Dunk in epoxy, completely cover.


ice boat build wetting out runner
Wetting out runner
ice boat build runner in jig
Runner Triaxila in jig


  • With wood body slot facing up, place centerline of fiberglass cloth along slot.
  • Push steel insert plate into slot. Make sure both wood body and steel are in forward direction.
  • Use poker to push through fiberglass cloth at holes for reinforcement rod.
  • Insert 8 pieces of stainless rod in holes. Hammer flush.
  • Smooth out fiberglass cloth on wood body faces. Work thickened epoxy into cloth, both sides.
  • Place bottom carbon fiber stiffener piece in mold, outside face down.
  • Place wood/steel/cloth runner on stiffener
  • Cover with top carbon fiber piece, waxed face out.
  • Close mold. Stand vertical, running edge down.
  • Trim fiberglass cloth from top of runner.
  • Clamp mold with even pressure until epoxy squeezes out.
  • Allow epoxy to cure before next step.


  • Take mold apart slowly, use hammer to tap all around before taking apart.
ice boat build Runner just out of mold
Runner just out of mold
  • Use belt sander to trim fiberglass and epoxy flashing down to wood body. This material is very sharp so be careful.
  • Shape front roughly with hack saw or band saw. Finish shaping with belt sander.
  • Use router and 1/4″ quarter round bit to radius all edges (except one along steel blade).
  • Seal top of wood body with 3 thin epoxy coats.
  • Drill 5/8″ hole 15 inches from stern of 36″ runner, centered 1 inch from top of wood body. Glue in bushing for pivot axle bolt.

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