INGREDIENTS:

• 1x mast bottom section (broken or complete)
• 1x mast top section (to be used as a hammer!)
• Hacksaw & sharp knife/blade
• Sandpaper with block (80-120 grit)
• Acetone & an old rag
• Epoxy & Q-Cell Filler
• 300mm x 200mm piece of 200g per m² “plain weave” carbon
• File (the bigger the better)
• Bank/Credit card (an expired one!)
• Plastic cup & stirrer
• Rubber gloves
• Masking Tape & a Pen
• Clear Plastic film (any thickness, any size)
• Tape measure.
• Glass of beer (optional)

Let’s get to work. I would suggest doing this outside (or in the garage if you’d like to escape your other half).

Step 1 – Cutting.

Cut the broken mast section to a length of 460mm (obviously one end is the bottom of the mast) – important to make the cut square to the edge of the section (otherwise in use the mast will bear on a point instead of the full circumference – refer Step 9.).  You can check by putting the cut edge against the bottom of a mast and marking the high points; sand the high points using 80 grit on a sanding block.

Step 2 – Sliding.

Select the section to use as the spigot which needs to be 270mm long (pink section in Figure 1a).  The mast has a taper starting at about 600-900mm above the base.  Slide the ferrule of the broken mast through the mast extender from the bottom until it is a firm fit.  Mark 150mm above the top of the mast extender; this is approximately the top of the spigot.  Remove the broken mast and mark the 270mm spigot + 50mm both ends of the proposed spigot. I use the masking tape to make these markings.

Step 3 – Knife Me.

Remove any plastic film/stickers/graphics on the mast so that carbon is exposed (best to use the sharp knife/blade to scrape and remove any film).   Give the spigot  a clean with the acetone to remove any glue used on the film and then a light sand to remove any high spots.  Now slide the broken mast inside the mast extender, get a firm fit – maybe force it a little and then re-mark 150mm above the top of the mast extender.  This point may have moved from the mark you made in Step 2. After you have removed the film and given it a sand, remove the broken mast.

Step 4 – More Cutting.

Cut the mast 270mm below the mark made in Step 3. Next, cut the broken mast 50mm above the mark made in step 3.  Now the spigot will be 270mm long + 50mm at the top as a contingency that you will remove later (Step 6) after the spigot is glued to the mast extender.

Step 5 – Cleaning & Peanut Butter

Clean the inside of the top of the mast extender and the outside of the bottom of the spigot with acetone.  In your plastic cup, mix up an adhesive paste using epoxy and Q-cell (filler) to the consistency of soft peanut butter and coat both surfaces with this adhesive.  Slide the spigot up from the bottom until you have 150mm + 50mm of contingency extending above the top of the mast extender.  Now with a rag and acetone clean any adhesive on the inside of the mast extender below the spigot (otherwise it will foul the adjustable mast extension).

Step 6 – Cutting? Oh yes we do.

When the adhesive is set, cut the extension of the spigot to length – 150mm above the tip of the mast extender.  Next repeat Steps 2. 3. 4. & 5 for the reinforcing cylinder (blue section in Figure 1a).  Tap the reinforcing cylinder into position with a mast top section.  Important to get a firm fit;  it will not be perfect as the taper angles vary slightly, but it needs to be firm!

Step 7 – Carbon Time!

When Step 6 is complete before the adhesive sets, you can then build up the diameter of the spigot where it extends inside the mast.  As this section is tapered use 1 layer of carbon reinforcement 150mm long and then a second wrap 75mm long (carbon rectangular strips will be approx 170mm wide – circumference of spigot + 10mm overlap).  Mask the top 50mm of the mast extender to avoid painting with epoxy in the next step.  Give the spigot a light sand and then clean with acetone. Wet-out the carbon with epoxy resin on a film of plastic and then use your bank card to remove the surplus resin.    Apply a light coat of epoxy resin to the surface of the spigot and then lay-up the carbon over the spigot using a gloved hand.  Now you need a strip of clear plastic about 40mm wide that you will wind tightly around the carbon overlapping the proceeding layer by 50%.  If you cannot find plastic, use insulation tape (do not use masking tape – it will stick to the carbon).

This plastic/tape clamps the carbon around the spigot to ensure a good adhesion and squeeze out the air and surplus resin that may be entrapped below the carbon.  Do this step carefully so that the carbon threads in the weave remain straight (If you try to tighten too much the carbon layer will twist around the spigot).  Position the lap in the top layer at 90⁰ to the lap in the bottom layer.

Step 8 – File Me!

After the epoxy has cured, use a file or sand paper to remove surplus epoxy at the step where the mast touches the mast extender.  It is important to have a well defined step to seat against the bottom of the mast.  Now sand the carbon layers on the spigot until the mast will fit; it is preferable to have a firm fit not sloppy. You will need to sand the lapped areas first to remove high spots.  I find it best to get a strip of sandpaper about 50mm wide, 250mm long and use it like you would polish your shoes (covering half a circumference).

Step 9 – More Filing.

When the mast will slide over the spigot check that you have good contact around the full circumference at the step; you may need to use a file to remove any high spots.

Step 10 – Oh yes!

Drink your glass of beer.

SAFETY

Use a pair of disposal gloves to avoid getting epoxy or acetone in contact with your skin.  Step 7 is quite messy as you will have to handle the wet epoxy carbon laminate.  If you get epoxy on your skin it is preferable to use a laundry power to remove the epoxy – not acetone as it is absorbed through your skin and will lodge in you kidneys.

Photos by James Briggs & Sean O’Brien

Q >> How did you get into the fin game?

I’ve always been active in sailing; both racing competitively and building equipment. I’ve built my own windsurfers (everything from Formula to Speed) and even a state of the art Sports Yachts back in 1993, which was featured on the cover of September 1998 “Australian Sailing Magazine” (see below).

Anyhow, I guess it was no surprise that I started talking with Boogie at C3 Fins back in 2002. C3 Fins had just won the FW World’s with Kevin Pritchard (USA-3). I became a bit more involved, by providing feedback and occasionally inputting into the development. When Boogie retired from making FW fins in 2006, he offered to sell us his IP and tooling.

In the early days we dedicated a lot of time working closely with Boogie, to make sure we re-produced C3’s extremely high standards. From there we started an ongoing development program. We still keep in touch with Boogie to bounce ideas around. (Actually I was just speaking to him yesterday!) I hope we can live up to Boogie’s hard earned reputation.

Q >> How do your fins differ from other fins currently on the market?

Originally, C3 molds started with A, B, C, etc, so we have continued along that line. The latest evolution is the ‘K’. We commissioned Boogie to develop the ‘K’ fin using his latest foil design. We then got down to the detail of developing the best layups to meet our performance requirements.

Looking at the current trends on the FW fin market, other designers have moved toward swept-back outlines with very torsionally stiff layups. We decided to go our own way with an outline with almost neutral twist. This gave us better ability to control the twist characteristics of the fin by the layup; without having to combat or trade-off against the ‘geometric twist’ built into a swept-back outline of other fins.

Q >> Your fins appear to be ‘lighter’ than other fins on the market? How so?

Yes, that’s usually the first thing a lot of people notice when they pick up one of our fins. We use 100% carbon in the laminate and because of our outline we only have to put the carbon in specifically to control the bend and the twist, not to counteract the twist produced by swept-back outlines. We also cure our fins under extremely high pressure and heat which allows us to get very good fibre to resin ratios which results in a minimal void laminate. We have a few secret ingredients which also help keep the weight of the fin down; developed by C3 Fins. Any weight saving on your rig is a good thing. Have you ever seen a winning skiff with heavy foils these days?

Q >> Do you have a range of fins?

We’ve pretty much finalised our range of fins. We already have specific bends of the ‘K’ model for different sailing styles and equipment. We’re developing cutdowns, which help extra light-wind performance and balance the super-wide tails of current boards. For the serious racers, we are continuing to build fins to their personal specifications.
We have just finished testing our latest prototypes and are very pleased with the results. The current fin is extremely competitive. The fins have been described as very easy to sail, with an automatic trim and a feeling of hydro foiling.

Q >> Who Is Behind VMG Blades?

Anthony Woodrow, Brett Morris & I.

Q >> But Who Are You????

I (Chris Ting, AUS-5) am the actual guy who builds the fins. I’ve been actively racing FW since it began in Australia and I headed over to Portugal for the FW Worlds last September. (I hope I can make it to Spain this year!) I am also the President of the Storm-Riders (www.storm-riders.com.au) Windsurfing Club in Sydney which organises the big and growing fleet of regular FW racing on the east coast of Australia. VMG Blades is based in Sydney, Australia, testing in Botany Bay. I hope we can see a lot more sailors head over this way and enjoy our windy summers down under.

Q >> So when can we order a fin?

Production is limited at the moment. When the doors are fully open and ready for business, I promise CarbonSugar will be the first to know!

In the meantime, if you’d like to enquire about our fins you can get in contact with us at vmgblades@gmail.com.

Is it because of the design of the masts? The shape of the sails? The materials and procedures used to construct the masts or just the incompetency of the sailors who leave them fully downhauled in the sun that is causing the slaughter of 100′s of masts a year?? My own personal opinion is that it’s a combination of all these factors but I believe that at least 50% of the breakages could be prevented by changing the construction methods of masts and also upgrading the materials used in the production of 100% carbon racing masts.

Looking at the masts I have used, broken, repaired and kept over the past few years and from discussions with my father who has done most of the repair-work on these masts, we have come to the conclusion that the general (as a general guide, there maybe slight differences between brands) construction of the majority of 100% carbon racing masts is:

• INTERNAL-LAYERS: uni-directional carbon wrapped circumferentially
• MID-LAYERS: uni-directional carbon running longitudinally
• OUTSIDE- LAYERS: uni-directional carbon wrapped circumferentially

Masts rigged in modern race sails receive high tension/compression forces on them through the application of downhaul, rather than simply being bent from the middle as in an IMCS test. The outside layers of the mast, which in the above construction have no carbon fibres running in the direction of the tension/compression forces, are susceptible to cracking, as the strands of the outside circumferential wrap can separate from the mid-layer longitudinal wrap, which causes the mast to solely rely on the mid-layers to take the full force of the tension/compression forces…. CRACK! BANG! SNAP!

In this construction there is nothing to handle torsional forces on the mast. When a mast is under load, there is tension on one side and compression on the other side; in addition to that there is torsional forces. The fibres usually aren’t constructed in the right direction to deal with the torsion!

If there was a different construction layup that used longitudinal threads on the surface, allowing the fibres to run in the same direction as the loads on the mast when it is fully downhauled inside a sail, the mast would be much stronger. This might cause the mast to be slightly stiffer, but superior in strength to the original construction. Surely there could be ways to deal with the extra stiffness or a different layup in the same concept which wasn’t as stiff?

There appears to be a general trend in windsurfing to use uni-directional carbon to build the carbon parts of our gear. Most likely because this type is cheaper, easier and more readily available. The more expensive cloths, such as 200g parallel weave (similarly used in Boeing’s 787 Dreamliner) aren’t popular in windsurfing product construction – probably because of the price increases occurred and also because when Boeing started building their planes there was a worldwide shortage of carbon (although this has somewhat subdued in the last 12 months). This product has also jumped in price by 300% most likely as a result of these new passenger plane’s coming into existence.

This construction idea might not be the perfect solution, but thinking about it is a start. I’m not naive enough to think that a simple design change will not make a considerable difference to the end consumer price of the masts and also play a role in further making manufacturing and distribution a little more difficult with an added price and the other costs/time involved with researching/designing/implementing/paying for/ a new design. Hey, I’m not a windsurfing company; just a person who hates reinforcing his BRAND-NEW masts all the time to stop them breaking.

I’m interested to hear what people in the community think. There is always going to be a two-way street with cost of manufacture (end price = $$$) versus material quality/reliability in any consumer product, but I am certainly a guy who would be happy to pay double for my masts if they had double the lifetime on the water.