Acquired an earlier build carbon fibre foil, and would like to build some strength into the base of the mast...near the plate fixing. Anything is possible they say, however is it viable from a non professional build? No access to autoclave or moulds as such. Looks like the foil was hand built with carbon lay up and standard epoxy resin. (No pre preg or autoclave)
Any suggestions, constructive advice is kindly appreciated?

Yeah I've seen it done. My buddy has a carbon fibre preproduction prototype foil that started off with a 100cm tuttle mount mast and after breaking (more than once) is now around 85cm with a plate mount. It's ugly but anything can be done. All the repairs and mods have been done by hand without vacuum equipment.

The short answer is yes.

the long answer is why? Do you or whoever is going to do it have glassing experience?

upload the photo so we can see and make better comments.

ps I build my own carbon hydrofoil.

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Plummet said..
the long answer is why? Do you or whoever is going to do it have glassing experience?
upload the photo so we can see and make better comments.
ps I build my own carbon hydrofoil.

Why...one can see it is the weak point...so would like to strengthen it before it breaks.(Actually on closer inspection it looks like it may have already been broken as there are some irregularities in the finish.) Good fun board to ride however. It is the Fenney foil that was for sale on Seabreeze for some time.

Most likely get an experienced person with the right knowledge and equipment to do it rather than myself. (Although one would love to attempt it myself)

Any chance you can send me images of your own build Plummet, either on Seabreeze or my email? One would like to see your creativity and ingenuity. What did you make your positive plugs out of? I have ideas for different profiles and want to make a model.

Stalk me in general kitesurfing tab. There's a foil board builders thread on there with tones of info.

i didn't make plugs. I manually shaped the core (bamboo) then vac bagged carbon over the core.

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Beautiful work man. Just beautiful!

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dorothyinste said..

Plummet said..
the long answer is why? Do you or whoever is going to do it have glassing experience?
upload the photo so we can see and make better comments.
ps I build my own carbon hydrofoil.

Why...one can see it is the weak point...so would like to strengthen it before it breaks.(Actually on closer inspection it looks like it may have already been broken as there are some irregularities in the finish.) Good fun board to ride however. It is the Fenney foil that was for sale on Seabreeze for some time.

Most likely get an experienced person with the right knowledge and equipment to do it rather than myself. (Although one would love to attempt it myself)

Any chance you can send me images of your own build Plummet, either on Seabreeze or my email? One would like to see your creativity and ingenuity. What did you make your positive plugs out of? I have ideas for different profiles and want to make a model.

Is one related to the queen?

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jamesperth said..
Yeah I've seen it done. My buddy has a carbon fibre preproduction prototype foil that started off with a 100cm tuttle mount mast and after breaking (more than once) is now around 85cm with a plate mount. It's ugly but anything can be done. All the repairs and mods have been done by hand without vacuum equipment.

I did this job and can agree with James that it is not as beautiful as what you see on production foils.

The junction between the top of the mast and the plate is very heavily loaded so you will have to pack up many layers of carbon fibre there (which I did and used vacuum pump).

An autoclave is is only required if the resin you use needs to be cured. I used K36 epoxy resin which doesn't require heat to polymerase but just for safety, I left the job in full sun for a day to help. It is also important to wait 5 to 7 days after a repair to get the resin up to full strength.

the main issue with this kind of repair is that your job will only be as strong as the mechanical adherence of the resine (you use resin as glue). Unfortunately with many resins, this won't be enough to copt with the amount of load in this area. Composite parts made in 1 go are stronger as they get the chemical bounding of the resine which you dont get when you relaminate on top of resins that are already dry.

The repairs I did on this mast lasted between 20 and 50 sessions. If I had to do it again, def must use vacuum pump, lot of carbon fibre, and good epoxy resin with strong mechanical adherence.
i also used 2 M8 bolts to bolt the plate on the mast which gave extra strength in the area.
wouldnt recommend the K36 as it doesn't seems to dry as hard and as strong as other epoxy resins I Ve come across. Plus it yellows quite badly after a year.

good luck

This is the first repair I did but the mast ended up separating from the new Tuttle over time.

Second repair with a carbon fibre plate added to the mast plus fibre on each side. Again, the mast separated from the plate and re-inforcment over time.

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dorothyinste said..
Acquired an earlier build carbon fibre foil, and would like to build some strength into the base of the mast...near the plate fixing. Anything is possible they say, however is it viable from a non professional build? No access to autoclave or moulds as such. Looks like the foil was hand built with carbon lay up and standard epoxy resin. (No pre preg or autoclave)
Any suggestions, constructive advice is kindly appreciated?

Hi dorothyinste

I am the guy with the mast that's been fixed many times by Luc. I would classify Luc's work (and i'm sure he would agree) as semi-professional. It worked great for a while but eventually broke, and it's not the first time it's been fixed. Luc spent countless paid-with-beers hours with the right tools and the right materials, but the forces applied on the foil are just too great.

My advice is unless you have a professional who can guarantee his work, to consider getting a better foil. If you're doing some ''home made'' repairs to it, don't expect it to last.

Good luck

Christian

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cbulota said..

dorothyinste said..
Acquired an earlier build carbon fibre foil, and would like to build some strength into the base of the mast...near the plate fixing. Anything is possible they say, however is it viable from a non professional build? No access to autoclave or moulds as such. Looks like the foil was hand built with carbon lay up and standard epoxy resin. (No pre preg or autoclave)
Any suggestions, constructive advice is kindly appreciated?

Hi dorothyinste

I am the guy with the mast that's been fixed many times by Luc. I would classify Luc's work (and i'm sure he would agree) as semi-professional. It worked great for a while but eventually broke, and it's not the first time it's been fixed. Luc spent countless paid-with-beers hours with the right tools and the right materials, but the forces applied on the foil are just too great.

My advice is unless you have a professional who can guarantee his work, to consider getting a better foil. If you're doing some ''home made'' repairs to it, don't expect it to last.

Good luck

Christian

Nah. It can be done!. Got to get more aggressive with your filleting onto the plate, run further up the mast with carbon. Check the hell out of the mast and plate. Hell. You could even vac bag a full length layer from plate to bottom of mast If necessary.

That's the beauty of composites. They are easy to repair and strengthen after the fact. It is true that you only get a mechanical bond once cured. But done right that mechanical bond wont let go!.

A most professional looking finish Plummet. Nicely done!

Hi Mate I have done it a few times on a Spotz foil. (Fuselage to Mast)
The tips I have are to make sure you sand the original back enough (grind) in a tapered angle.
Important is to use carbon Unis . So much better than 0-90 cloth which you should use for your last few layers.
Must use epoxy
Cant see how you would achieve any real success with out Vac Bagging due to the tight 180deg turn at the bottom
I would charge @ $400 to do it as I guide. I am in Melbourne.
The end result will always be a little more drag than the original.
Its usually not worth it in my opinion.