View Full Version : Insert Wood Into Carbon/Fiber Tube: Rule-Of-Thumb For Length?

03-15-2012, 04:44 PM
I want to make a steering oar and have an 8' section from a broken carbon-fiber windsurfer mast that seems like it's made for the loom.

ID of the fat end is 1.5".

I figure I will take a piece of 2x2, run a router over part of it to make a round that will slide into the mast section and then edge-glue a couple of 3" wide pieces to the square portion and shape the blade from that.

If that sounds reasonable, then the question seems tb "How far in to the windsurfer mast do I need the wood to go?".

Is there a rule-of-thumb based on the tube's diameter?

I'm not looking for great precision.... just don't want to go overboard on the length, since whatever length I choose will probably have tb tapered.

Also, at the risk of muddying the waters: any suggestions on how to secure the blade inside the mast section?

I'm thinking that if a blade breaks off or just turns out tb the wrong shape it would nice to not have the wooden shaft epoxied in there where it couldn't be removed/replaced readily. Maybe this is overthinking.... expecially bc facilitating removal would have to take into account swelling of the wood over time... and such a loose fit wouldn't work in the first place.

Ron Williamson
03-15-2012, 05:35 PM
I'd do something like 4 diameters into the tube and start the blade maybe 2 diameters away from the tube.
I'd use a flexible hardwood like w. oak or ash for the blade with a carriage bolt to fasten it.

Dan St Gean
03-15-2012, 06:11 PM
I did that on a less structural application of the sprit boom. For a steering oar, I think doug fir would be fine. Spruce would be even better as it's lighter. Sticking the wood in the carbon windsurfing mast--it doesn't need to be too much. I like Ron's idea of 4x the diameter. You could also hack it off if it breaks and drill out the offending piece if it isn't up to you liking.