In last week’s post we showed how we made carbon fibre chainplates for Paikea. The chainplate arrangement was originally a stainless steel strap with a backing plate bolted through the bulkhead. The bulkhead was a eglass/plywood construction that had lasted more than 30 years but now the plywood core had rotted away and only the glass was left to hold the chainplates in place. As a result, the bolts were slowly moving upwards towards the deck and allowing the chainplate move upwards also.
Our solution was to build a new carbon chainplate laminated onto a new piece of bulkhead made from eglass with a foam core. The question we were asked was how do we stop the new bulkhead piece which was butt jointed to the rest of the bulkhead stay in place and not pulling through the deck with the load from the chainplate? The answer is we use a DB eglass sandwiching both sides of the carbon chainplate to distribute the load from the chainplates to the rest of the vessel. This distribution of load is critical to the correct function of the chainplate arrangement.
If you are interested in chainplate arrangements an example of another arrangement where the composite chainplate is attached to the hull instead of the bulkhead can be found on our blog post about the inside of a Modern Carbon Fibre Race Boat.