SURFBOARD FIBERGLASS FABRIC TYPES

E-Cloth or Electrical glass (Plain weave)

Is the most common type of surfboard fiberglass cloth sold, the individual yarns are a 50/50 construction, meaning equal strands going “fill” direction (rail to rail) and “warp” direction (nose and tail).

Warp Glass

Warp glass has more yarns in the “warp” direction (nose to tail) than in the “fill” direction (rail to rail) This allows the strength to go where it’s needed most, nose to tail. Warp Glass lays flatter on the board using less resin to saturate, the end results are a lighter finished surfboard.

Direct-Size (D-size) Our Brand SI-14

Direct-size is E-glass that is not heat cleaned (baked in an oven) This saves 30% to 40% of it strength. It’s a great alternative to S-glass, direct size gives nearly the same strength as S-glass but at a much lower cost.

S-Glass

S-2 glass was the first developed for military applications. S-glass is made from higher quality raw material (magnesium) and is about 30% stronger and 15% stiffer than E-glass. Most commonly used to provide greater strength with less weight than with E-glass. S-2 glass is compatible with polyester and epoxy resins. Great for surfboard decks where heel dents and pressure dents are common.

Types of finishes (primer) on fiberglass fabric:

Silane finish (primer) – Regular clear finish most commonly used in surfboards and is compatible with both polyester surfboard resin and epoxy surfboard resin.

Volan finish (primer)- Original marine and industrial finish. Fiberglass manufacturers in the 60’s hadn’t developed a surfboard specific cloth that is clear when it’s wet out, the result was a greenish look or “Coke bottle green” appearance.