Builders' Forum Archives
Re: SH 17 +carbon/kevlar
Posted by LeeG on Jan 25, 2006
ok,,,been thinking about this. You can use a 2" diameter piece of the carbon to hold on recessed footbrace bolts.
The kevlar is a challenge,,how about cutting a 18" piece,, unraveling the strands and bundling them up in one loose cord,,experiment making a skid plate out of soaked (cabosil/epoxy) bundle of strands,,forming with alcohol as it cures. If you allow for a flattened area on the bow/stern,,about what you'd put a 3/8" piece of half oval brass,, you could form the kevlar on that, making it about 1/8"-3/16" at the thickest portion near the stern,,about a 6" long section with the cord extending up the bottom panel to the side panel and along the keel about another 6"
The thing is that any impact that can utilize the strength of those materials will most likely result in major shredding of the exposed plywood so the repair will still be a glass/wood repair at the juncture where the kevlar/carbon ends.
I did some testing of 4mm panels reinforced with various materials,,,2" wide 10oz unidirectional carbon tape as well as 1 1/2" 5oz kevlar tape with and without glass cloth. When the panels were broken or punctured the wood failed long before those materials did. Where there was a tendency for the whole panel to bend with just glass it would break on panels that had carbon on one side.
Before the aft decks on the Chesapeaks were reinforced at the hatch holes and deck glass I put some unidirectional carbon under the aft deck from sheer to sheer. But another strip of 4mm plywood worked too.
In Response to: Re: SH 17 +carbon/kevlar by Bob on Jan 24, 2006