Pre-emptive Repair Required to new CST Mast Spreaders

 Since the first new 49er / FX mast was presented at the 2020 Worlds, testing and modifications have been undertaken to ensure we achieve a robust, reliable product. Now with the new CST masts in action, sailor feedback indicates the new spreaders on the CST masts require further strengthening. Note, the spreaders are not made by CST.

If you have a new mast, a strengthening modification to your spreaders is required.  This is a pre-emptive repair that is quite simple to do yourself.

Eventually (a few months) a new spreader laminate will be developed, but until such time new masts leaving the factory will also have this modification.

The modification involves the application of 2 long strips of carbon or basalt fiber at the inner end of each spreader arm.

The modification shall be made using 2 x 300g uni-directional fiber tapes no wider than 10mm and no longer than 500mm, per tape on each arm.

The first ribbon must be placed as close as possible to the castellation ring (the alloy ring round the mast). The second ribbon must be spaced 50mm from the first ribbon. The ribbons are applied using any reputable epoxy resin system.

Julian Bethwaite has created an easy step by step video that explains what needs to be done to make the spreader modification –

To make this modification you will need:

  • Unidirectional carbon fiber or basalt (sourced from a local boatbuilder)
  • Gloves
  • 25mm masking tape
  • 120 grip sandpaper
  • Any reputable epoxy resin system
  • Stick to mix
  • Brush
  • Electrical tape
  • Cutting knife

**Furthermore, we strongly recommend that you use rigging or insulation tape on the spreader tips to firmly locate the spreaders on the wires. This will help reduce the spreader flexing.

You will likely have to remove the IHC sticker to do the repair. A new sticker will be supplied and fitted next time you see your builder or builder representative.

As a thank you for doing this repair, we would like to offer 50% off your next spreader purchase, should you do the repair yourself, to be redeemed within the next 6 months. Just send us a photo of the fixed spreader.

Alternatively, you may prefer to have the spreaders repaired by your dealer. Just contact them.

Mast base fastening

Some sailors have reported issues with their mast base. We strongly recommend that you glue the aluminum tenon permanently onto the plastic which would prevent possible failure. All future masts supplied will have the tenon glued permanently.

While we’ve conducted many tests and trials to ensure the mast’s robustness prior to launch, we admit the testing program was hampered with Covid lockdowns, shipping supply issues and the Olympic date moving out. Unfortunately, the new spreader falls victim to these issues.

On a positive note, we are excited with what we’re seeing with these new masts in terms of increased toughness and very minimal variation between masts compared to the previous masts.

Thank you. If you have questions or further feedback, please contact either:

Julian Bethwaite :

John Clinton:

John Mcafee: