I'm fixing a broken ferule on a Hypersonic 55% carbon mast, do I have to match the carbon content or it doesn't matter? I've got an old but structurally sound thick walled epoxy Ampro wave mast ('80s) that I am considering using for donor parts, will this be suffice? I don't care if it adds weight just concerned it may affect the curve or be a weak point due to lack of carbon content.
Bump....
This mast was given to me today and I'd like to start on it ASAP, will the above work OK?
I repaired a broken ferrule on an 80% carbon SDM by using the tip off an old fibreglass mast and sleeving the inside of the ferrule. I tapered (sanded) the internal wall of the sleeve where it went into the bottom section of the mast so as not to unduly create a point load on the wall of the mast. Glued it in with epoxy resin and it seems to have worked a treat - have used it now around a dozen times in fairly testing conditions (it's my small sail mast). Whenever I rig it though I ensure the cracked ferrule (now filled with resin) is facing to the inside of the luff to ensure it is in compression rather than tension.
Do you really want to test your "glassing foo" by determining how long you will spend swimming? 
FNova, it'll be a complete new ferule. All plugs and broken ferule in top section has been knocked out today. The donor part is fibreglass epoxy resin, it was a very tough mast in its day. I will glue the new ferule with epoxy and maybe double wall it as well, I'll match lengths with the broken bits internally and externally.
sausage, like you it will be my small sail mast as it's a 400 and is reassuring that yours works. Found some instructions on the net on how to do this but no specific mention of base material of the ferule. Just thought that alike materials will flex the same. I'll double wall the ferule...maybe. The top and bottom mast sections are intact and shows little use which is why I thought it worth while. I think the hardest part is going to be getting out the glued in broken ferule. Lots of gentle chipping and careful internal sanding sez the instructions.
I have 2 part epoxy glue (slow), that should be OK to glue the ferule in?
Are 55% carbon masts that expensive, it's worth repairing them ? Personally I would not want a) the hassle of doing all the work, or b) take the risk that my dodgy home repair would stand up to the pressures of the downhaul and the wind.
That is a very reasonable explanation and fair enough ... Good luck hope all goes well.
