I got my first foil setup which includes a Katana mast from Unifoil. On the mast there is a sticker which implies that the mast is sharp, and that one might consider sanding it down. I’ve posted a pic below of this. There are a few places I’ve read people talk about sanding down the tips of the front wings of their foils for safety, but not the mast.
Is this something that would be good to do given that I’m a beginner and it’s likely I’ll bump this thing in the water?
You have to work really hard to touch the back of the mast. I almost never come into contact with it. As a beginner you’ll kick the stab for sure though and cut your feet. If you are nervous and have to sand it mark off and don’t touch/sand the bottom 6 in of the mast. That’s the most important part for efficiency and ventilation.
Safety tips - use a leash in the beginning - if you feel it pulling your safe , no pull cover your head and face.
Anytime I go down and I’m not 100% in control of the board I have one arm wrapped around my face, hand on the back of my head.
Practice keeping you feet glued to the pad when you go down - I’ll be upside down and backwards in the whitewater but my feet are still controlling the board
Thanks for the run down. If it’s pretty rare to come in contact with it I’ll probably leave it then. I have muscle memory from surfing to cover my/head face when I fall.
As far as other safety stuff is concerned, I am planning on using a leash in the beginning and I also have a helmet.
Just remember that you have to clear the board by two feet on every fall. Once you’re used to that you’re pretty safe.
Don’t correct, eject. Trying to save a fall is what gets surfers in trouble when they’re learning. Keep your entire body in line with the mast. Don’t lean out over the rail.
I sanded my trailing edge. I just took a block of wood wrapped in 120 grit sandpaper and ran it the full length of the mast one pass at a time until it didn’t feel deadly. I have not experienced any ventilation or unexplained dropouts while proning, winging or downwinding.
Peace of mind is worth the half % of efficiency that I may have lost.
Evolution Cedrus is “soft” relatively speaking. 95A shore hardness to be exact, at room temp. Much softer than carbon fiber or aluminum, and we’ve definitely had clients claim the rubber edges saved them when crashing into the mast.
Blunt trailing edges (sanded) have no performance impact whatsoever. Definitely no contribution to ventilation either, which initiates at the leading edge and where the mast pierces the water.
If there is no performance loss why do manufactures (besides yourself) insist on making them so sharp? Is it one of those things that is “perfect” on paper—but realistically there isn’t a measurable performance difference when riding?
I would much rather get stabbed by a butter knife made of rubber with a hardness of 95A vs. one of carbon fiber or aluminum. Shore A scale covers the 1-10MPa range for Young’s Modulus, and to put that into perspective, aluminum is 70GPa… at least 7,000X stiffer. I didn’t say it was a good idea, I said one was better than the other. Also not everyone is foiling cold water.
I also can’t speak to other brands, or know which ones insist on sharp trailing edges. But our work with experts who have designed foils since before the type of foiling we’re talking about here was even a thing, have shown us data and analysis that suggests super sharp edges have no performance benefit in the reynolds numbers we are talking about. Alternatively, the sharp edge is more prone to damage, causing injury, making noise, and harder to manufacture.
It could be I have the pre released versions (both are like that). Kyle could clarify.
Mind you when water is 2-15C it’s hard.
But even then it’s not hard enough to cut.
And I’ve cut myself with the Gong ultra sharp foils.
Levitaz (not slow!) use the Donaldson angle on their foils, those are not sharp (still sharper than Cedrus mast
There is a +/-5 tolerance on the shore hardness of the edges. This is common with RTV urethanes, especially on products that are made by hand in smaller batches. So one rider could in theory have a 100A (off the A scale) and another with 90A, and they would feel different. Temperature has a huge impact, so both could feel much harder or softer depending on whether it’s been baking in the sun on a warm beach or being ridden in 50F water.
The coating is not ceramic. It’s cooler than that. It’s a zero-VOC (100% solids) sprayable, UV-curable clear-coat system with slip & mar additive. Another industry first, it is extremely scratch resistant. But it does retain some flexibility so it doesn’t crack when the edges are flexed or deformed. This was a really hard problem to solve!
Did not want to hijack this post. Just wanted to clear up some confusion bust mostly ease concerns that sanding your edges is going to drastically impact performance. It wont.
I had a situation where I was paddling out through shore break pushing my board from behind. a wave caught the board, pushed it back towards me and I got cracked in the brow with the trailing edge of my mast and left a gash. I’ve also had leash recoil situations where the mast comes close to bonking me. Just pointing out that weird situations happen and it’s definitely possible to get cracked with any part of the foil.
I haven’t sanded the mast but I always wear a helmet now.
Good to know that a duller trailing edge doesn’t impact performance.
I sanded my Katana trailing edge with 220 grit sand paper to take the knife edge off of it and finished it with 400 and then 600 grit.
I feel like it is a lot safer now. I use it for prone and kite foiling. When kiting imperfections lead to whistling. My Katana is silent after dulling out the trailing edge.
For learning I also chopped the tips off of a 14” G10 tail and also sanded down the trailing edge to make it safer.
Now that I’m a bit over a year into prone I’m riding the stock Progression tails as is.
Thanks for all the helpful replies here. I opted to knock some of the edge off with some 220 sand paper I hand around. Didn’t take much off, just enough so that it didn’t feel near razor sharp anymore.
I do have to save. The ONE bad cut I’ve gotten in two years of foiling was with the back of the mast, and it was my face. lol. I was even wearing a helmet. It was on Maui winging when I fell in the white-water. I lost control of where my board was and the leash brought the board back to me in a hurry, from being loaded. The back of the mast, about halfway up, tapped my face at an angle, so the helmet wasn’t able to deflect. Anyway, it cut me about 3/4" of an inch, but did leave a bad bruise because the tap was hard it enough that it bruise bone (cheek bones). So I also ended up with a black eye.
I was able to suture it with tape and you can barely see a scar now. But I was out of the water for 10 days during my trip due to this.
