Originally Posted by garymcc
Do you know if it is feasable to insert a wooden dowel inside a CF tube as a long term solution? I do not know the implications of binding those two dissimilar materials on a critical load bearing structure. I did it short term and it worked but only for a few flights before I was forced to retire the plane.
I am wondering if I need to reinforce my spar as the I.D. is about 4mm or so and not .188 (4.7mm). I am thinking a 5/32" dowel insert and Gorilla Glue and be done with it.
A birch dowel is what you want in a size that snugly fits inside the stock tube you have if you cannot find CF in a size that fits. You don't want poplar dowels.
You said you did it but were forced to retire the plane. Do you mean it failed in the joint between a birch dowel and CF or what?
I am lucky enough to have KITE store that makes high end kites in my area. I would take the piece you have in your plane and go to the KITE shop (which sells me all my CF) and try to find a size that would fit in tightly, buy it an go home and glue it in with Gorilla Glue. 4 mm may fit. I don't know how big the ID really is unless you measured it with gage pin. If you can't find CF that fits then find metric birch dowels.