How to turn Diving fins into a Fluke

Do you have an old pair of diving fins you don't really care for? Are you thinking of getting a monofin but you just don't have the money? In this tutorial, I'm going to teach you how to crop an old or unwanted pair of diving fins into a fluke shape!


Materials
- Fins
- Duct tape
- Hot glue
- Caulk gun
- Liquid nails (weather-proof)
- Electric saw
- Silver sharpie marker

Total cost estimate: $15
(based off what I had to buy)
Currently selling for: $20

Project Duration Estimate: 2 days

Everything in this tutorial can be found locally. The liquid nails, duct tape, and hot glue can all be found at your local multipurpose stores.

Overview:
This tutorial will teach you how to turn an old pair of fins into a nice looking monofin with a fluke-shaped cut. We will be cropping and reattaching the blade of the fin until we get a desired result. Since the finished product will be covered with duct tape and probably not look as pretty as most people would like, I'm going to suggest the use of these fins when using a mermaid tail.

WARNINGS:
This tutorial calls for the use of electrical tools. When using an electric saw or cutter, it can be extremely dangerous if percautions are not taken. Always wear splash-proof goggles to prevent any debris or dust from the cut to get into your eyes and gloves to prevent any hot plastic or rubber from getting onto your hands and potentially burning them. You should always ask an adult or friend to help you with the tools. If you're unsure how to use them, please ask someone who knows to help you out!
Liquid Nails is also a potentially harmful substance. When wet, always use gloves and do not inhale the fumes it releases. Always work in a well ventilated area.

Always make sure you read through the entire process before beginning to avoid mistakes and get a general idea of how the project will progress.
Now let's make get started:


Step 1: Test your fins
A strange way to start the tutorial, however, it's a necessary step. The very first thing you should do before finalizing your choice of fins and deciding to tear them up is to test swimming in them. Swimming in a monofin is much different than swimming with regular fins. The monofin forces your legs together and restricts movement, so it often takes practice to get the swimming part down. Not only that, but regular store-bought monofins are designed so that your legs point straight down, whereas when rigging a pair of fins together often causes your feet to point outwards. The width of the blade of the fin is what causes the outwards slant, so if your blade gets too thick towards the end, it may be too uncomfortable to swim in properly and you may need to try another pair of fins. Testing your fins can tell you alot about how your project is going to turn out, and I find it very necessary. Not only that, but its fun to do anyway!
Before we can test the fins, we need to tie them together somehow. Nothing permanent, just a quick tie will do, since we're only testing them out. To do so, we're going to use duct tape. Use the tape to completely circle your fins right below the toes, on top of your feet, and behind your ankles. Layer the tape at least 3 times to make sure it's on nice and tight. Place a couple lines of tape running the length of the inside of both flippers. Check the picture for a nice idea of where to do it. Before you get in the water, make sure the tape holds the fins stiff. There should be no individual movement from either fin, they should be stuck together pretty well. If they survived, reinforce the duct tape with a new layer, and you're ready to move on.


Step 2: Marking your fins
Once you're happy with the monofin you've made, it's time to write all over them. I used a silver sharpy marker for my fins and I really liked it, so I'd recommend that. If not, a normal sharpie works too. Now, what we're going to focus on right now, is the inside of the fin. For the fluke shape, the center comes to a curvy V shape, kind of like a { shape. We're going to be looking at the very inside part of the fin, though. Notice how a dolphin's fluke extends out a whole lot on each side. Don't worry about that, we're going to get to it later. So sketch the inward V and mark to the edge without worrying about sketching the tips of either side of the fluke into your fins.
HOWEVER, you need to make your mark close enough to the toe area so that you cut off a nice amount of the blade off. Reason being, you're going to need a decent amount of it to re-create the outside of the fluke. Don't worry if your fins look like they're going to be too short, it's more important that we capture the width of the fluke so it'll look more realistic.


Step 3: Cutting the fins
Now for the tricky part, we need to cut off the excess fin blade. For this, I used an electric hand-saw and it was very tricky. Even with an electric cutting or trimming device, you're still going to have to take it slow so you don't mess up. Try to get as close to your marked lines as possible and make your cuts nice and smooth. Most flippers are either made from plastic or rubber, so chances are, some molten stuff will be flying at you. Wear gloves and goggles for safety and if you can, get someone to hold down the fin still while you cut it, or vise versa.
Once you cut out the excess fins, you're going to be re-arranging them to make the length of the fin. It's sort of hard to explain, so I've provided a picture of what I did to mine. Sorry guys, I didn't take any pictures of the process, it was super tedious. It's not perfect, and your fins may be a little different, anyway, so it may take some playing around with. Simply take your excess blade piece and move it along your fin until you see an area you'd like to place it. Trace the area where your fin lies near it so you know where to cut so that it can be attached perfectly next to the fin and then crop off any extra that you need to in order to achieve your shape. I made 2 pairs of fins and I made them both using the excess a total of 2 different times. In other words, I cropped it once, and then I cropped the remainder again. It's just trial and error, really. Just sketch it out and compare it before you actually cut it to prevent mistakes and don't don't DON'T forget to label the pieces of the fins! Label them R for right side, L for left side, TOP for top piece, BOTTOM for bottom piece, etc.


Step 4: Attatching the pieces
Now that you've got all the extra pieces you need to attach, it's time to bond everything together for good. First, we'll attach the actual fins together, then glue on the pieces we cut. Tear the old duct tape from the swim test and attach your fins together with some hot glue down the center of the shoe area and all down the length of the center where the blades touch. The hot glue will not be the only thing holding it together, we just need it for now to ensure that the fins are held together temporarially while our liquid nails dries. Now that your fins are kept together, ready your caulking gun and add some liquid nails to the center areas where the hot glue is. If there is still a large gap inbetween the shoes, work with small layers of liquid nails rather than a large one. A large blob of liquid nails will dry on the outside much quicker than it will on the inside which will result in you thinking it's dry when it's really not and possibly messing it up, or it never actually drying at all since it will never completely cure on the inside of the wad. I've got personal experience on that one. Anyhow, add liquid nails down the center, where the fin blades meet. Next, we need to attach the extra pieces we cut. To do this, use the hot glue in the same fashion. Hot glue is great because it'll hold well and it dries quickly, but it's not the only thing we're using, so don't get scared. If you have a friend, you should REALLY convince them to help you out. Doing this part alone is hard. If you don't have a friend, get your parents or something. Anyway, start attaching pieces on one side at a time. First attach the tip piece that matches the end of your fluke and then add the bottom piece that reinforces it. It's important to make sure that the fluke shape is one solid curve rather than some uneven edges, so it's important to always put that piece on first. Hot glue EVERYTHING in place first, and then allow it to dry for a couple minutes. Once it's dry, set the fin flat on a bucket or table where the fluke piece can hang off the edge. Now, apply the liquid nails over the areas where the pieces are attached and spread it out along both sides of the fins. When the liquid nails dries, it has to be able to grab onto both sides of the fin to hold them well, so just kind of use the tip of the bottle to mix it around. Add liquid nails to every piece that was attached and allow it at least a couple hours to completely dry and cure. Once it's dry, cover the fins with duct tape in the same manner as you did before, over the parts where you slide your feet into the fins and down the center, and add a whole lot of duct tape over the extra pieces you added on as well. Press the duct tape down hard so that it sticks firmly and doesn't crinkle too much. Press down any areas that may stick up or collect water underneath them as well. The duct tape will reinforce our liquid nails and keep it together, so you must do it as well as you can to prevent the fin edges from breaking off. Once you're done, wait a whole day just to be sure that your liquid nails completely cures before our next step.

Step 5: Test it again!
And now for final and possibly most fun step. Test out your new fins! Don't test them lightly, either. This could be the best or worst step, but it's completely necessary. Swim in the fins as you would with normal fins, don't be gentle or scared to break them either, swim fast and kick as you would normally. If they do happen to break, then you may have possibly not reinforced them enough and you need to go back and repair them twice as hard so that they don't. What you should be careful of, though, is to bend the edges too much on the floor or walls of the pool. They can bend nicely, but don't slam them on hard surfaces or that might be what actually causes them to break. Just so long as you can swim in them normally, they should be good.\


(click the picture for a swim test video!)


And there you have it! A nice monofin with a realistic fluke shape! Now all you need is a nice mermaid tail to slip over it!

For more information on purchasing jewelery and other props in my tutorials, requesting a custom item, or an idea for a new tutorial, feel free to email me at Kanti-Kane@hotmail.com (: