Monday, February 21, 2011

Carbon mast tangs Mk II

I made the Mk I carbon mast tangs a couple of moths ago, and it turned out quite OK, but not good enough.  So I developed the moulds to be able to take them the little step further.  I have now made the first Mk II tang and I'm very satisfied. This will be the mast raising eye.

Step 1:  The central 6mm thick fibreglass lining is placed between the moulds and secured with a bolt trough the moulds and the fibreglass.  This way I was able to use lots of force to compress the UD carbon around the glass tab.  The ends of UD carbon is spread like a fan and placed between two layers of triaxial carbon in the mast shaped part of the mould.

Step 2: De moulding and preparing two extra layers triaxial each side of the tab.  Hole for the bolt visible here, as is the ready cut triaxial for next step.

Wet lay up, and the three part mould is assembled again.  Home made "screwing clave" providing superb consolidation during cure:

De moulded and trimmed.  Using a router bit to make bellmouth hole for lashings.

Mounting: A rectangular hole made in the mast wall.  Peel ply removed.  The part will be bedded in micro fibre thickened epoxy and laminated over from the inside.  The loads should be well distributed to the mast wall without point loads.

Showing how the headsail blocks will be attached.  Not on this tang though, as this will be for the mast raising wires.

The headsail and headstay tabs will have a slightly different shape.  Fibreglass inserts in production:

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