[Ian McColgin]

I second the notion that it takes lots of holes to make a problem, holes you'll be adding if you to a rivited external reinforcement.

I am no engineer and am far more sensitive to wood than metal but hollow wooden spars can be ruined by a repair that creates a hard spot. Depending on the designed flex in the spar, you could make a hard spot that establishes a failure point just beyond it, though usually tri spars are compression loaded and should not bend as a mast does.

An exception is the radical Gougeon Bros racing tri's that have the motto "Free the amas" with laminated spars designed as huge wooden springs. Perhaps your rig somehow does that with aluminum under compression and some flex from the guying design ??

Anyway, I'd be inclined to use some epoxy paste to plug the hole and otherwise just watch it a while longer.

G'luck

Ian