A DIY Carbon Fiber Mast

[Alext]

Thanks for the input. All things considered. This is the concept I based these ideas on.



When we are done sailing we take the mast down and fold the sail.

[Alext]

I did the layup of the first roll of carbon fiber today. 8.6 meters long and 1 meter wide.
That makes 3 wraps, 0.83 mm thick. Richard Woods recommended 1.5 mm wall thickness
of aluminum. I want to put 6 layers, that will give 1.68mm and should (I hope) be strong enough,



I’ll add the next roll of carbon fiber tomorrow. Then let it cure.

[Alext]

[Jeff]

Nice work!!! Jeff

[Jaysen]

I’m not sure if your “thickness equivalency” is correct. I checked a round mast here on a freedom 40 and it was much thicker than an aluminum equivalent.

If you have validated your layup that’s great. Stick with what was approved. If not you might want to have a material engineer weigh in to be safe.

That said, it looks great. Makes me dream of doing that for my little boats.

[fallguy1000]

To support Jaysen's comments a bit. Richard is a minimalist. In a carbon diy mast; this can be bad. One way you can verify that a hand laid carbon mast is sufficient is weight. It should NOT be less than 20% lighter than aluminum. Carbon masts are best painted to avoid repeated maintenance of clearcoats every 2-3 years.

I am watching the post with interest because also building a 12' carbon beam.

Can you explain the process of how you did the lamination? How did you keep the carbon from sliding at the start?

[fallguy1000]

Also, post your mast and boat specs on boatdesign.net to verify the layup.

[Alext]

Again thanks for the input, it is very much appreciated.

I should post this cat, it is designed by Richard Woods.
I finally got the last 2 coats of polyurethane, set for 24 hours
and moved it outside.



I moved the Zest into the part of the shop that I put a 4.5 meter door on.

It’s a long story about this item on my bucket list since I was 10. Trying to buy a mast, a sail, etc.

The carbon fiber mast is a test, an experiment if you will. I’m taking every piece of information I
can get and applying it. Richard did not endorse this mast, in fact he strongly encouraged me to
buy a mast.

I’m estimating strength/weight/wall thickness. When it is built and on the step, I will have to
decide if it seems to be strong enough to transport to the lake for further testing.
My friends sailing club. If it appears not strong enough at any point of testing, I will sand
and add more layer of CF.

Thanks again for the input. Alex.

[Alext]

As for the lamination, I wish I had taken pictures. I will add that to this post in a day or two.

[Alext]

I’m using PVC as a core. Paint the PVC with common PVC adhesive and let it dry.
This will give a good surface for the epoxy to stick to.

At first I did my beams, at 2.45 meters (8 feet) max, they were much easier. I propped
up the PVC tube at each end. It could be rolled it but not easily, I want it to stay in place.
For the mast, much longer, I put 4 round supports, positioned to keep the work straight.
The mast will have to be lifted off of the supports and turned. In each case the supports
were covered with plastic packing tape.

Paint the PVC dried surface with a nap roller. I used a 100 mm (4 inch) wide roller. Let the
epoxy get tacky. ( I didn’t actually let it get tacky, my epoxy takes several hours to get tacky,
I don’t have patience for this.)

At one edge of the fabric stretch it end to end on the PVC core. Let it hang down in front of
the core. I used my hands to stretch the fabric to remove the wrinkles. Moving from one end
to the other. You will need to lift the fabric to get the wrinkles out.

After the wrinkles have been removed from a section, say 100-120 mm (4-5 inches). Use the
roller to apply epoxy, sparingly to that section. Turn the form to do the next section. When you
have gone all the way around the PVC tube you are working back onto where you started. Try to
tuck the first layer under the second layer and remove any wrinkles. As much as possible. Continue
rolling, laying the fabric and applying epoxy as req’d. I work the fabric from one end to the other,
then back.

Once the whole piece of fabric has been laid up onto the PVC, it’s time to get my hands in. I keep
a bottle of acetone and a good supply of rags handy. I rinse my hands with acetone and wipe it off,
with a rag. Keep clean when using.

You could leave it here if you like. There is excess epoxy and the fabric will not be tight. It will drip
and probably sag.

So I use my hands to work the fabric, stretching and squeezing out any extra epoxy. I want the fabric
to be wet but not drippy. I work it until there are no wrinkles, no loose fabric and the epoxy is getting
tacky, so it won’t drip.

If you allow the epoxy to dry, remember to sand it before adding more.