Internal Carbon Pins

[Peach Canoe]

I often use Western Red Cedar for decks because it's light and beautiful. WRC is fairly soft, but the deck is somewhat protected and doesn't get too beat up.

But it's prone to splitting. Therefore I've been installing carbon pins that run through the deck and both inner gunwales. The pin is a .250" carbon fibre tube that's epoxied in-- I use a long drill bit in a drilling jig, and drill holes for 3 pins in each deck.

Here's a photo showing the longest pin through the deck and inner gunwales on a Kevlar Caribou S pre-Clipper.

 

[Mihun09]

So if you need to remove the deck you either drill out or cut the pins?

 

[Peach Canoe]

If I need to remove the deck I just saw it out, clean up the cut, and glue in a new one. Carbon tube pins saw like hardwood; I've made boats with no metal whatsoever-- everything is glued and deep-fastened with carbon pins or epoxy + filler pins. These boats are noticeably stiffer.

A deep-fastener is like a screw or lag bolt, and some boatbuilding specs call for the use deep-fasteners to augment the very local surface of a glued joint. A carbon fibre pin works like a lag bolt or screw, without the issues of corrosion and the local stress on wood fibres around screw threads.

You can deep-fasten a joint by drilling out holes (say 1/4 inch diameter) on either side of a glue joint and filling the mating holes with epoxy and filler before assembly.

Infused composite gunwales are very stiff. I epoxy and deep-fasten all of my wood gunwales to their hulls.

But then, there are the arguments of aesthetics and repairability. There is no 'correct' way to do most things.

 

[Alan Gage]

Nifty idea. I imagine they look pretty sharp on the exterior as well, a perfectly plugged hole.

Those are hollow tubes or solid rods? If hollow I presume you fill them somehow?

Alan

 

[Canotrouge]

Look like carbon arrow shafting... You can get some of them for really cheap from time to time....

 

[Peach Canoe]

The carbon pins in the photo are internal-- I cut them off at the hull before I install the outwale. They just go through the deck and the inwales, so they can't be seen from outside. They're a hedge against the WRC deck splitting. I don't use metal screws anywhere.

These CF tubes are 1/4" OD with a 1/16 wall. You can find them at hobby stores. Arrow shafts are more sophisticated and are larger (5/16 or 9/32) with a thinner wall-- but they would work (they're stiffer too), but more expensive.

Yes, I fill the 1/8" hole with epoxy, but you could leave them hollow if you like.

 

[Jim Dodd]

Cool way to solve the problem created by the WRC, and keeping it light.
Good idea !

I'm planning on reducing the weight of my trim on CF Nokomis. I may look into that a little closer. My son has some pretty thin CF Arrow shafts that might be less than 1/4".

Jim