Hi all,
Broke this mast recently (pictured below). It's a Severne Gorilla 340. I'm hoping to be able to salvage it by getting the piece of the bottom half , which is stuck to the feral, off the feral (doesn't matter if i fully damage it as i don't need it), and then cutting just above the break of the rest the bottom half (the long piece) and somehow modifying the feral or the bottom half so the two pieces of the mast can be put back together. Obviously if you try to slide the cut and shortened bottom half onto the feral as is with no modification it will not be a snug fit as diameter of bottom half will be too much for feral.
Does anyone know if this is possible and if so have any ideas as to how it can be done?
Any comments appreciated.
I would not consider a break there to be repairable. Ends, yes (just) but not there.
I'm curious about the CK wrap though did it have an existing issue and then 'strengthened" and has later failed? I'm guessing it broke through the CK area asd I'm seeing all those sanding marks on the 'clean' bit
Select to expand quoteImax1 said..
Don't muck around with a mast further than you can swim .
And, I've found swimming vastly overrated when the water is not flat calm.
I think Decrepit repaired some masts, so maybe he can chime in. I've only done one carbon boom that seems to be holding up just fine after the repair. But obviously, I don't have to worry about messing up bend curves.
Lookin terminal. Dont risk it.
Itd make a good garden stake.
I made an Outboard Tiller extension from a broken SDM section.
Nice n light, looks trick n it floats.
So is the C.K. just boom strengthening, or as Mark suggests a previous repair?
Peter, I don't think I've ever repaired a mast with a break there. But Sambo's idea of throwing the damaged section away, and converting it to a shorter mast, could have some merit.
As said the ferrule will be sloppy, the easiest way is to increase the ferrule diam with layers of glass.
The bottom section would need to be cut back to a totally undamaged area.
But that's going to make the mast much shorter, and probably affect bend curve and stiffness to a certain extent.
So nothing guaranteed, but worth the experiment. If you have a sail small enough to use it with.
If you are just looking to separate at the joint (where you'd normally separate) and aren't worried about repairing the bottom section then you can try the two booms and a mate method and twist them apart.
Alternatively I've seen a hammer method work (much more fun hitting things) if really jammed.
You would have to cut the end square, then they had a plug which fitted in the end with a shoulder wider than the end of the tube, but I would suspect you could do it with a block of wood to cover the end.
With the plug in place and the heaviest hammer you have, lay the mast on the grass, stand on the bottom section and give it a what in line with the axis of the mast (imagine the mast is a nail), the shock wave goes through and shifts the top section up of the ferrule incrementally.
Good luck
If the ferrule is in the undamaged top section, and the bottom, broken part is disposable, simply split and peel it off. 
Your proposed shortened mast will end up stiffer of course, but when you can make up the length with a (long!) bottom extension, it may be usable.
That CK wrap looks to me like standard issue factory boom reinforcement seen on a few brands of masts.
Note that the section of the mast that goes over the ferrule is normally thickened and reinforced, so it would certainly be a good idea to wrap some reinforcing around the bottom part that fits over the ferrule.
Another possible option is to buy the bottom half of a compatible mast with the same size ferrule? Some RDM mast brands sell tops and bottoms separately. I have not noticed that Severne do, but that would be the ideal.
And lastly, I have seen one to two successful mast repairs for such a break, but they are very technical and difficult to do well. It could be an option if you know someone really good with composite materials. And even then, I would not venture far from shore with it.
PS, And always 'tape' your join. That eliminates the stuck mast syndrome 100%. 
I should have mentioned in my first post that the mast is only going to be used for foiling in a 3m sail. So there"ll be far less downhaul tension on it compared to rigging it for windsurfing and far less load on it when in use (foiling vs windsurfing) . I know shortening it will mess up the original stiffness and bend curve too but if I can salvage it, it will do for now until I can get my hands on a new mast.
In light of the above any thoughts anyone?
Select to expand quoteMark _australia said..
I would not consider a break there to be repairable. Ends, yes (just) but not there.
I'm curious about the CK wrap though did it have an existing issue and then 'strengthened" and has later failed? I'm guessing it broke through the CK area asd I'm seeing all those sanding marks on the 'clean' bit
Not quite sure you mean or what the CK wrap is. I assume CK wrap is the yellow stuff indicating the reinforced area of the mast that a boom can be clipped onto?
If so this area has never had an issue or failed.
The mast broke due too repeated catapults over time, due hitting large carp in the lake where I foil, in combination with my boom being clipped on above / outside the CK wrap ( reinforced area ) of the mast in order to get the boom height I needed on one of my sails.
The reason I ask is it is not factory on a Severne mast. Somebody had added the Carbon/Kevlar layer - and to me that suggests prior damage.
Then, boom outside the reinforced area will definitely do it 
If you were outside the CK area you were waaayyyyy outside the actual boom attachment area (as designed) that is reinforced at the factory (not the CK wrap)
Were you trying to use a 340 with huge amounts of extension or something.... ?
Anywya I still say not repairable and if you chop the bottom and use it as a 290 or300 mast, you will have the same problem with the boom being in the non-reinforced area. And a woeful bend curve.... OK for kids rig at best
C.K. = carbon kevlar composite, you'll see one strand in the weave is yellow the other black.
Select to expand quoteMark _australia said..
The reason I ask is it is not factory on a Severne mast. Somebody had added the Carbon/Kevlar layer - and to me that suggests prior damage.
Then, boom outside the reinforced area will definitely do it
If you were outside the CK area you were waaayyyyy outside the actual boom attachment area (as designed) that is reinforced at the factory (not the CK wrap)
Were you trying to use a 340 with huge amounts of extension or something.... ?
Anywya I still say not repairable and if you chop the bottom and use it as a 290 or300 mast, you will have the same problem with the boom being in the non-reinforced area. And a woeful bend curve.... OK for kids rig at best
That's strange, the mast was new from The Zu Boardsportsyears ago. Mabey Severne use to CK wrap that area of their masts. Had to clip boom outside boom clip area
to get needed boom height on a 3.7 Naish Lift foil sail that I longer use.
Select to expand quotesailquik said..
If the ferrule is in the undamaged top section, and the bottom, broken part is disposable, simply split and peel it off.
Your proposed shortened mast will end up stiffer of course, but when you can make up the length with a (long!) bottom extension, it may be usable.
That CK wrap looks to me like standard issue factory boom reinforcement seen on a few brands of masts.
Note that the section of the mast that goes over the ferrule is normally thickened and reinforced, so it would certainly be a good idea to wrap some reinforcing around the bottom part that fits over the ferrule.
Another possible option is to buy the bottom half of a compatible mast with the same size ferrule? Some RDM mast brands sell tops and bottoms separately. I have not noticed that Severne do, but that would be the ideal.
And lastly, I have seen one to two successful mast repairs for such a break, but they are very technical and difficult to do well. It could be an option if you know someone really good with composite materials. And even then, I would not venture far from shore with it.
PS, And always 'tape' your join. That eliminates the stuck mast syndrome 100%.
Thanks
Never seen a Gorilla with CK wrap in boom area. Maybe the really early ones did, but this looks like a G2 logo. Something is wrong.
Regardless, if you rig with the boom way out of the reinforced area it will bust.
This is not repairable. If you cut it down, the dia will be wrong at the ferrule, and grinding away there to make it fit is asking for trouble.
You have 2 or 3 really good rod holders, and a spare top section..
