Windows

The following is an article contributed pre-2012 by John Somerset, Cavelle. John no longer owns Cavelle which went to QLD some years ago I believe.

John Somerset, Cavelle

I recently updated my windows as follows-

1. Removed all frames and bond the outer and inner skins with 6mm spacers for strength and consistently thick openings. Then fair to give a clean line.

2. The clears were replaced with 6mm  "cast acrylic" (not rolled) as it lasts 5 times longer than lexan (polycarbonate)

3. These were attached with double sided 12mm wide ~ 2.5mm thick tape and a bead of sealant and finally trimmed/sealed on the outside with more sealant.

The 2.5mm tape provides a consistent gap for the sealant to allow  movement of thermal expansion and hull flexing. The tape also gives a good finish on the inside between the hull and glazing.

As shown in the pix it gives a nice clean finish inside and out.

Materials

• • Half a sheet of 6mm x 2400x 1200 tinted cast acrylic  - $120 …. More durable than Lexan and half the thermal expansion. All professional boat builders use Cast Acrylic or Glass. Supplied by Plastral

  • Sealant - Dow corning 791N   - $10 / tube x2 ….Black, UV and salt water proof. 50% CTE. Supplied by Lincoln Sentry.

  • Vinyl Ester resin, fillers, glue and flowcoat  ~$50 …. Twice the strength of Polyester and impervious to Moisture.  Supplied by AA Fibreglass supplies

  • Double sided  3M 4991 VHB tape $85/ 30m roll (best quality) about 10m used. Supplier- HARRY DAINES PTY LTD

  • Paint- spray pack epoxy enamel black and cream. ….Black border on the inside of the glazing to hide the tape and sealant. Cream 25mm border on the inside to cover fairing work.

The skin joining and faring took about 10h per window plus 2h fixing the clears. A lot of work but great result!

Many thanks to my consulting team Bruce Allen, Paul Cracknell and Google.

The skin joining and faring took about 10h per window plus 2h fixing the clears. A lot of work but great result!