It's almost fun to watch someone else like Armie sand. I make my own foils and there is an aweful lot of sanding. Sanding models, moulds, wings, mast and each in multiple grits. This last couple of weeks I tidied up a half dozen carbon wings and my carbon mast. Good to have spares. I mix up about 25 grams of epoxy, add a tint powder and light weight filler powder and mix until I can't get any more filler powder in. And then I use a plastic wedge back and forth to fill bubbles, scratches, nicks. Remember to wash your foils and fully dry first though! I have 4 diamond grit sanding blocks, Great for convex surfaces. A budget Ozito orbital battery sander for wet sanding with the red sanding disks from bunnings and the purple ones from super cheap auto. For a lot of material removal I find going under 120 grit is counter productive, grits like 280 actually remove material quite fast. Sanding always goes faster if you wait a few days for the epoxy to fully harden up. Hit it too soon and the epoxy will capture grit particles, especially if you don't wet sand. Wet sanding is so much better though!
What a fun video! I dig Armie's approach and attitude: wear and tear are just part of the game (but the rock...oof. Sorry Matt). I also got a tip ding that I sanded a bit--couldn't bring myself to modify the other side yet. I've been gun shy about taking the grit to my scratches too; maybe slightly less so now!🤙
Do I hear humming at speed because I need to sand my foil? MA1750, 60 fuse, 85 mast, cant remember the back off the top of my head. Great video. Thanks for showing us how easy it is to keep the foil tuned up.
Humming could be caused a variety of ways, I would try and approach it like an IT guy to start, simple steps to eliminate options for the issue. Probably start with a full disassembly/reassemble if you don't often. Once assembled give it some wiggles, are any parts moving more than normal or making noise? Are all screws and connections fastened all the way? If there's visible damage to your wing, that could be it too. I just would start with other options to rule them out before sanding your wings.
Thanks! Super helpful. Arnie; you sanded the bottom surface of the foil with 1000 grit in the direction of the water flow. Would it be proper to do the same to the top side as well?
Yes to maximize your performance, you can use 1000 to 1500 in the direction of the water flow of all surfaces including the top side. I think that most people would be hard pressed to really feel that difference unless they are really pushing the limits of foiling.
I have never sanded a Donaldson edge, but I was always told that on a tailwing, the opposite side of what Armie was saying in this video around 5:30 should be the rounded side. He said that the lifting side should be rounded, but isnt that opposite of what he demonstrated? Doesnt a tailwing "lift" in the opposite direction of the front wing?
It depends on what side of the wing has the camber. Some tails have the camber on the top and some on the bottom. In this video he is doing it correctly for the side of the wing that has the camber. Hope that helps.
I have the counter view on repairs. Do not sand dings out fill them in. Use acrylic auto body filler and a hotel room key to fill dings and scratches. Then wet sand the excess off. For major cuts and cracks baking soda and crazy is and instant super hard fix. Use in small amounts and shave excess immediately with razor blade. Then finish with filler. This preserves the original shape and integrity of the foil.
I would have paid to see Matt’s face when he whacked the hell out of that foil😂 people try and make it so complicated. It’s not. Armie just showed that.
I was curious what he was doing with the rock and then almost died when he wacked the foil. Nut job! That foil did look like it was attacked by a tiger before and works killer now.
Great video! Any chance you could make a video on how to reduce drag by sanding board bottoms, masts and foils? I hear water over water is less drag and 400 to 600 grit surface achieves this. The rounded Donaldson trailing edge should be on the flat high pressure side to prevent noise. Because water tries to make a sharp turn to flow from high pressure to low pressure and that's where the noise comes from in my experience and research. 😎🤙 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-NqSaGl7Qb3s.html
@@kittengray9232 it depends on the speed through the water, at very low speed it makes limited difference, at higher speeds it is critical and yes you can feel the difference from wet sanding a production foil so it is significant, not as much as changing a tail or main foil but its more the icing on the cake. When you saw this video and Armie mentioned that racers don't want your finger prints on a foil because it makes a difference that gives you an idea of what lengths people go to to get the last bit of performance, wet sanding to a fine grit is a well known gain and its not disputed, finger prints are probably still in dispute with some. There is not really a down side to a well finished foil
I was looking for this comment. I was second guessing myself. I also thought that the rounded edge should be the flatter side (which is the opposite of what Armie was saying/doing).
Does sanding make any difference at all? Water is a lubricant in it's own right. My guess, water has no problem circumventing the imperfections. Have anyone measured before-after performance? I mean in numbers?
Imperfections caused by scratches and dings cause drag. The drag can really be noticeable in how smooth the foils feels as well as how much control you have at speed. I do foil with friends that are very specific about keeping their foils sanded right and others that trash their gear. Both cases these riders rip really hard. So sanding and tuning your gear does make a difference but great riders can ride through the imperfections. The main thing is to keep up with your gear and tune it up if you get any scratches or dents. It will keep your foil in good shape and reduces the drag.
