......to pinch a phrase from some emails I get 
Anyway my new sail has 189 boom, my so-called 140-190 goes to 189 only when measured 
Plus, of course when tuning I will need 2cm more at some stage, AND don;t want to sail on max extension anyway..... so an extension was in order.
So, not going to drill more holes to make my boom 1-2cm longer...... but if I get another tailpiece, extend it, then drill more holes - yup 
Drilled centre, bit of Bunnins crap 16mm ally pipe glued in with epoxy.
Tapered end, then glass - carbon -glass wrap
Bit of pipe over the top (with mould release) to ensure it is concentric then filled with resin and qcell
4 more holes :)
Be careful that the alloy and carbon don't explode with electrolysis 
Ive been told this will happen , could possibly catch fire .
Neat job 
Here i was thinking i was gonna hear some story about an anvil and some superglue.
Looks good. Be interesting to see how it goes.
oh yeah. getting that alloy sleeve off was a mongrel.
Cut a slot in it if thinking of using that method :)
I would have used PVC or similar but I just could not find anything at all with a 21mm ID
Ive done a similar extension on an alloy Gaastra boom. Found alloy tubing that ham radio guys use for extendable radio masts to be exactly the right dimensions. Epoxied the sleeve together. Extra 180mm. Used it regularly for the past year. No issues yet.....
