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Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 10:27 am
by patrelsa
i have a new liquid force mast and plate and new slingshot mast and plate .i want to permanently bolt them and wrap them with carbon 5 oz unidirectional,for more stiffness, look,and feel.I have bent the masts easily in the past and want them quite stiffer so i wont bend the new ones...any prep suggestions(sanding,removing paint,,or coating)downsides,advantages,recommedations for layup,bolting and glueing before layup....thank you for any tips or suggestions

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 2:07 pm
by handy
dont think that this is a good idea. Alloy "works" quite a lot when temps are changing , carbon not much.
So if you put your mast from hot sun into cold water your alloy mast will "shrink" but the carbon layer not.
For me, delamination is what will happend.

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 2:13 pm
by Lokihel
Actually carbon and aluminium have very similar heat expansion coefficients, which is why aluminium moulds/mandrels work well for prepreg carbon.

However, permanently bonding the two isn't a very good idea: they will form a galvanic couple.
On carbon spars, all aluminium or stainless steel parts are isolated from the carbon so there is no electrical connection between the two.


What you could do if you are skilled is use your existing mast as template for a full carbon mast. You could polish your mast and use it to make a plaster mould for your carbon mast.
I am not too sure about the building details though, but there is a lot of information on this forum about that.

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 5:47 pm
by plummet
Mountain bikes have alloy lugs etc imbedded in carbon frames. They seem to bond and ok. But they are no continuously emersed in salt water. I think it will be possible particularly if the alloy is fully encapsulated.

However it will be heavy plus you will still potentially have the possibility of bending the alloy plastically as the carbon layers can flex past the alloys yield point. Also you will increase mast thickness which will.reduce performance.

Ultimately if you have the skill to lay up a carbon mast you should make one without an alloy core.

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 6:37 pm
by wingnut
the amount of money you will spend to make this happen will afford you two carbon masts. take it from someone who has done the math. not only that but you could likely end up with a total unsaleable mess that is way too heavy. Foiling in light wind requires the least mass; kite, rider, board, foil, mast and ego.

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 7:54 pm
by Peter_Frank
patrelsa wrote:
Fri Dec 29, 2017 10:27 am
i have a new liquid force mast and plate and new slingshot mast and plate .i want to permanently bolt them and wrap them with carbon 5 oz unidirectional,for more stiffness, look,and feel.I have bent the masts easily in the past and want them quite stiffer so i wont bend the new ones...any prep suggestions(sanding,removing paint,,or coating)downsides,advantages,recommedations for layup,bolting and glueing before layup....thank you for any tips or suggestions

As others has suggested - I would not go this path :roll:

HOW are you bending the otherwise in general really strong alloy masts ? (And how many as you write in plural ?)

Are you a lot over average weight ?
Are you hitting something, or hitting the bottom sand which also can be a disaster for ANY foil ?

Something does not sound right here, I have to say, and maybe you could address this first ? :wink:

If you use a lot of time trying to reinforce with carbon over the alu, it might not work...
And even if it does, you will break the foil at the connection points instead, having such an extreme amount of load :(

8) PF

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 8:25 pm
by Eltreato
Also interested in knowing how you are bending the masts...

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Fri Dec 29, 2017 11:19 pm
by TomW
Don't do it.
Sell and buy a CF set up. Or stay with them as is.

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Sat Dec 30, 2017 3:42 am
by patrelsa
thank you for your suggestions .....i will use wood core instead......im 120 kilos carving very hard into wave face in 25 knots of wind with alot of speed on a 4 meter kite putting alot of leverage on the wings and mast.....and i can bend them quite easily both liquid force and slingshot....but they were all warranteed....

Re: Wrap alu mast with carbon fiber for stiffness

Posted: Sat Dec 30, 2017 4:41 am
by BWD
You should maybe get in touch personally with slingshot and perhaps zeeko and explain your situation. They may be able to get you a “hybrid” of windsurf foil mast (stronger) and kite fuse/wings. Or some other brand that does kite and windfoil Al foil sets...