Sad Guy Has Repair Questions About Broken Carbon Boom

[Binx]

Snapped my Fiberspar carbon boom, on both sides, midway between the mast clamp and the adjustment collars. The breaks occurred on the straight section of the tubes, aft of the curve. (Tail of boom okay.)

Is it possible to repair this boom? Maybe an aluminum or carbon "collar" overlapping the broken joints?

Is it generally unwise to attempt this kind of repair? Will the fix eventually fail, resulting in ANOTHER long swim? (Thankfully, Waconia's water temp is currently not unpleasant. I can vouch for the water temps between the island and the DNR landing, as I side-stroked the whole @#*%+ distance towing board and rig.)

Goes without saying that carbon booms ain't cheap. Appeciate any and all advice.

[JRN]

Gorilla (urethane) Glue is the solution. It expands inside the joint. Find some aluminum or carbon tubing that fits snugly inside OR OUTSIDE(SEE BELOW) your spars. Sand off any splinters at the break, and make sure the sleeve overlaps the joint by 3 or 4". Coat it with glue, slide it inside OR OUTSIDE the broken pieces centered on each side, clamp & wait overnight. The glue will expand and any excess will run out & dry. Scrape off the excess, sand 'til smooth, and go sailing.
I sleeved my favorite fiberspar mast with a piece of old aluminum mast 7 yrs. ago and have been using it ever since. I would suggest that you dry-rig it with a big sail and stress test it on land it a stiff breeze, before you trust it on the water. Good Luck!!
PLEASE NOTE: The internal sleeves will only work if the break and subsequent repair are beyond the area where the tailpiece slides in & out.

[Binx]

<<Find some aluminum or carbon tubing that fits snugly inside your spars.>>

JRN - thanks for the good advice. Am happy to hear that your repair has held for 7 years.

My original thought was to use an external sleeve much like the collars used in copper tubing for water lines. I'm no engineer, but common sense tells me that your internal plug is a better idea - structurally and cosmetically.

Just want to verify that I understand you correctly: your sleeve is located inside the spars, and you didn't use any "external" reinforcement like a collar or fiberglass wrap, etc. Yes?

Finally, any advice on where to find a suitable plug?

Thanks!

[JRN]

MAJOR WOOPS!! I FORGOT ALL ABOUT THE TAILPIECE!! DUH! U R right, it would have to be EXTERNAL not INTERNAL sleeves in order for the tailpiece to slide in and out. I have also wrapped the pieces with fiberglass for a tighter fit, & then aplied the urethane. I have tried both marine tex & fiberglass on the outside of the joint for reinforcement, but they had diffferent flex characteristics and kept cracking off. It might be less so on a boom than a mast. I am not an engineer either, just a shade tree nut who loves to experiment. At my shop they call it, "JIMGINEERING." Seth has the degree, the giant brain & the knowhow. I would not use copper, but the strongest yet lightest materials available, & plenty of overlap on the joint. How about a ball from a game of jax for the plug? Test if for compatibility with urethane first. Keep in mind that the glue expands and wants to push any loose parts out of position. So clamp, tape or otherwise secure everything before it dries.