surfresearch.com.au  bill reid : styrofoam surfboard 1953

This method was employed by New Zealand surfboard builders in the 1950s-early 1960s, as balsawood and polystrene blanks were difficult to obtain due to import restrictions.

Stryofoam, or Coolite, in combination with expoxy resin was used for a short time in Australia by McDonagh Surfboards in the late 1950s.
See:
1958 Ross Renwick : Build a Plastic Foam Surfboard.
Australian Outdoors, November, 1958, pages 11 and 58.

The styrofoam-epoxy combination may have also been used by some American manufacturers.

This method became an accepted manufacturing method beginning around the mid-1990s, following years of intensive and expensive development by sailboard manufacturers, now comonly called epoxy boards

The board is 9 ft 6 inches x 25 inches with four strips of styrofoam laminated with a plywood stringer ("keelson"), pre-shaped to set the bottom rocker.
It is recommended that the blank is shaped with a "vegetable grater" and the resin applied with a brush.

[1] Foam-plastic "boards" are glued together just like wood to form the body of the surfboard. A center stiffener, or "keelson," of 1/4-in. plywood gives extra strength and rigidity. Board is sawed to shape when glue is dry.

Page 158
 

[2] Cut curved edges of board with a keyhole saw. At this stage handle board carefully to avoid chipping edges. Square forward end before gluing headpiece. [3] Vegetable grater is used to round edges of board to contour.  Grater does the trick faster as foam plastic does not abrade easily.  Note in detail that bottom is nearly flat. [4] After applying sealer, spread muslin and impregnate with sealer.  Apply to one side only and allow to dry before applying sealer and fabric to opposite side.

the clamps, place softwood strips under the jaws of each clamp to prevent the narrow jaws from crushing the plastic at the edges. Note in Fig. 1 how the boards are clamped.
After the glue is dry - and be sure it is thoroughly dry- square the torward ends and glue on short lengths of plastic to bring the length to 9 1/2 ft.
Then cut the board to the rough shape shown in Fig. 2.
Finish to contour as in Fig. 3, using a vegetable grater rather than sandpaper.
The former does the trick faster and more smoothly as foam plastic does not abrade well.
Note the sectional contour as in the detajl on page 159.
The topside, or deck, is rounded at the edges but the bottom is left flat for stability.
When rounding, be sure that the contours are uniform on both sides.
A simple cardboard template will help in checking for uniformity of ihe curves.
Next, apply a foam-plastic sealer to one side of the board and, while still wet, dampen the muslin and smooth it over the sealer as in Fig. 4.
Be sure that the fabric is in full contact over the surface then apply a second coat of sealer, brushing it well into the cloth.
Allow one side to dry before applying sealer and fabric to the other side.
When dry (allow at least 8 hr.) turn the board over and apply sealer and cloth in the same manner.
The fabric should overlap at the edges about 1 1/2 in.
Give the laps an extra coating of sealer.
After both sides are thoroughly dry, sand the surface lightly.
The final covering of glass cloth gives the board strength and rigidity.
You'll need about 3 1/2 yd. of glass cloth and 1 gal. of laminating resin.
You also will need a catalyst and hardener especially made for use with this product.
Before using, be sure to follow the instructions for mixing the materials.
Now cut glass cloth to size and layover one side of the board, preferably on the side opposite that on which the first piece of muslin was placed.
Coat immediately with the resin "dope," being

Page 159

[5] After sealing, board is finished with a "skin" composed of glass cloth impregnated with a laminating resin.
After mixing in accordance with instructions, this "dope" is applied over the glass cloth with a brush.
Remove all wrinkles and blisters.

[6] Hardwood skeg is attached with a glass-cloth fillet built up on each side.  Fillets consist of several strips laid In resin in each corner where the skeg joins the board.  Finally, the wood is covered with a single thickness as in the right-hand photo. [7]

careful to spread the liquid in a uniform film, Fig. 5.
Smooth out any bubbles or wrinkles may appear.
When one side is finished, allow to dry before covering the opposite side.
When cutting the piece for the opposite side, be sure that you cut it wide enough to allow a 1 1/2in. overlap at both edges.
Apply in the same manner as the first.
Figs. 6 and 7 show how to attach the skeg, which is cut from 1/2 or 3/8-in. oak to approximately , the shape shown in the detail below.
It is about 8 in. wide and 12 in. long.
Round the curved edge, then center the skeg on the stiffener.
Some trimming may be necessary to assure a true fit.
Brush the edge of the skeg, and also the area where it is to be placed, with the resin coating.
Locate the skeg and then build up a rounded fillet on each side with strips of glass cloth laid in resin dope.
Follow by covering the skeg with one thickness of glass cloth, trimming and overlapping the edges as in Fig. 7.
As the final step in the construction, make a kneeling pad just aft of midships by laying two or more thicknesses of glass cloth in resin.
Apply a final coat of resin to the entire board.
Allow coating to dry thoroughly before using board.

Popular Mechanics Magazine Volume 100 Number 1. July 1953.

---

---

surfresearch.com.au

---