Introduction: Tentacles!

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The need for tentacles is universal. There are many aspects of life that would do well with more tentacles, and appeasing the Great Old Ones in your life is not the least of them.

There are of course many ways, and some include the growing of actual tentacles from eldritch seeds on a substrate of demonic leftovers under the light of a dying star. But not everyone is fortunate enough to be blessed with those things.

So I present to you another way. One that can be done literally without messing with the fabric of reality. It also requires very little secret arcane knowledge. The only caveat is that there is geometry involved. If that is too great an evil for you you can always try to find a dying star.

Disclaimer: In this Instructable I am describing a technique, not a project (except in the video). That means that I am trying to fit a lot of possibilities into this. As a result, things might sound vague. If you want to make tentacles, read through the whole thing and decide what works best for you. Then do it and learn from it! Then help others learn by posting your experiences! (And of course, stay safe and use your best judgement!)

Step 1: The Video

I have used this technique recently in creating a can-based abomination. Why, you ask? Because I can. *crickets*.

Anyway, check it out for some good old entertainment as well as a moving visual of how I made these. Then we can move on to the theory and practice of tentacle making.

I also did a follow-up video where you can find a little more explanation and the 2D example from the next step in a moving version. And then there is the original monster-in-a-can . So many videos to watch...

Step 2: Plan Your Moves

This is probably where you expect me to tell you how to use this technique to a certain goal. Get a particular shape. Make something specific. Initially, I thought I wouldn't. But I will. When first writing this, I wanted to put the planning stage last to make sure you would read through the technique to get a better idea of what to actually plan. Instead, I will say that power tools can be dangerous.

Be careful when making angles and sometimes awkward cuts, and don't do anything you don't feel confident doing. Also, you are responsible for your own actions.

That being said, the idea is this: you cut a piece at angle X, turn it by 180° and glue it back in place. That results in an angle of 2X in the tentacle. To illustrate the point, check out the example in the next step. And I do not mean to alarm you, but there are three dimensions. So in your effort to create something truly horrific, you are free to make that cut in any orientation you want.

If you change the plane of the cut between operations it will introduce a twist into your design. And to make matters even worse, while rotating pieces 180° will leave you with matching surface areas, you can also rotate it by any other angle. This will leave small parts of one side extending over the other, but for a slithering look, you will need to sand the whole thing anyway. So, you have even more options!

But let's take it slow for a change with a bit of 2D theory in the next step.

Step 3: 2D-Theory

Let's start with a 2D demonstration. Check out the pictures and annotations for the best experience. I mean, seriously, I know I tend to talk too much, so I though in this step I let the images do (most of) the talking.

Step 4: 2D-Theory-Summary (say That 5 Times Fast)

So there are two basic principles at work here:

  • If you make a cut of angle X° you will get a kink in the tentacle of 2X°. I should add that in 3D, where you can turn the piece anywhere from 0° to 180°, you can get lesser angles as a result.
  • If you place your cuts closer together the change in shape will be more pronounced.

Step 5: Materials

The material needs to fulfill several demands. You have to be able to...

  • cut it. For reasons that should be obvious after we did that thing with the paper.
  • shape it. Because (even if you forego the taper in the next step) you want to be able to sand the material later. (Admittedly, it is not common to have a material that you can cut but not shape, but I am being thorough).
  • glue it. Tentacles falling to pieces is not a good first impression you want to make with dark entities.
  • not smush it. What I mean is that it needs to retain its shape even when you press it together. So no tentacles from butter. You know you thought about it. At least you did now.

For me, wood fulfills all those criteria. Metal would work if you are proficient with it (and possibly weld instead of glue). Materials like Corian would probably make for an interesting look. Plastics should work as well but are sometimes less forgiving (heat buildup, glue resistance).

If you want larger and/or flexible tentacles I recommend that you use eva foam. In that case, go the "foam smithing" route and use a pattern to make the "skin" of the tentacle. If you are looking for more on the subject, check out the works of Kamui Cosplay or Bill Doran.

Step 6: To Taper or Not to Taper

Traditional tentacles have a taper.

That means they have a tip on the thin end, while the other end is broad and usually attached to something. Tradition is not something you should consider breaking when dealing with Great Old Ones. But when you merely aim to decorate, why not throw tradition under the bus?

Let me make this clear: this technique works well without the taper. You can use it to "bend" dowel material of any size if that is what you feel like. If you do go for a taper I recommend using a wood lathe, mainly because I have access to one. A sander should work well, but you need to pay more attention to keeping things symmetrical. A little more out there is using a scroll saw or a band saw (if you dare). Just make sure to keep things symmetrical-ish.

And let's not forget the good old spokeshave. One of those tools that does what it does better than most powered tools. Any Old One's favorite for sure.

Step 7: Mark It Out

Once you have your shape in shape you need to mark a reference line from the tip to the other end. This will help you determine how far you spun the piece on the saw of your choice (if that is something you want to do. And you probably will), The easiest way to do that works only when you chose not to use a taper.

Place a pen on something that elevates it to the midpoint of the piece when lying on the workbench. Then move the pen along the workpiece (or vice versa) and voila. For a tapered one, things are a little more complex. But our eldritch overlords will love you for it.

If you can, prop up the smaller end so that the centerline of the proto-tentacle is level. Then use the method described above. If you can center the piece between two larger boards you might be able to drag the pen through the opening, but since that is the method I tried to use (in a way) I cannot recommend it.

Step 8: Make the Cut

Now we come to the heart of the matter - cutting the tentacle apart. There are several ways to do that, and all of them require a saw. But there are some things you need to consider first. The cut surface needs to be flat, and you need to be able to control the angle, all while being safe.

Here's what I did: I used the miter saw to make the cuts, using a still-square piece from my blank to hold the workpiece safely against the saw's fences. Cutting round objects on the miter saw is not my favorite pastime, so I recommend that you read through this whole 'ible before you decide what method works best for you.

So here is a quick rundown of all the tools I could think of that would make sense here:

  • miter saw -in my opinion best for getting angles the way you want them and to hold the piece against two perpendicular surfaces. But also the most dangerous one of the lot. Only use this if you are confident that you can keep your fingers away from the blade. Use push sticks and scrap pieces as hold-downs. Move the blade very slowly and think before you cut. I just feel I need to say it.
  • table saw - right up after the miter saw the table saw can also do angles well if you have a proper miter gauge. Since you move the workpiece as opposed to the blade, I consider this slightly less than ideal, though. It is also dangerous for fingers and the likes, and especially holding smaller pieces is a lot harder than it is on the miter saw. The same safety tips apply.
  • scrollsaw - while the safety for fingers it a lot higher on this saw, it is also much harder to create a flat cut (something I will go into in the next step). The blade is very flexible and can wander easily. If you are fine with doing some sanding afterwards this might be a good tool for you.
  • bandsaw - I ranked this one below the scrollsaw because it can do more harm if things slip, but also because it is more likely to create bowed cuts on top of a slightly ridged cut surface. That may be a personal experience and not that big of a deal to sand away, though.
  • handsaw - in my experience, you can do amazing things with a handsaw and skill. If you lack the skill, though... You can make straight and perfectly angled cuts with a handsaw, but it can also be a frustrating process followerd by a lot of sanding.
  • knife - only for really soft material. And I said no butter!

Step 9: Make the Cut Flat

Getting a flat surface on your cuts is recommended with the strongest wording possible. When you rotate a piece and glue it back on, any imperfections on the surface will cost you in terms of contact area and thus glue strength. If you can hold the piece safely, a miter saw or a table saw are the best options to get flat - due to the nature of their sawblades alone.

If you are using a saw that is not prone to flatness (i.e. bandsaw, any handheld saw) you can use sandpaper to remove ridges and waviness, but that may in itself be a sources of non-flatness. Make sure to back your sandpaper up with something rigid and flat (like a pane of glass). Otherwise, sanding might remove smaller kerfmarks but create a larger curve in the cut face.

Another way to deal with slight imperfections is to use a gap-filling glue. More on that later in the step about gluing the tentacle back together.

Step 10: A Word About the Taper

If you are going for tapered tentacles you have to keep in mind that one end is way thinner than the other. Which is the whole point of tapers, I would argue. But if you place the workpiece against a fence (like on the miter saw or a table saw's miter gauge),

Step 11: Glue the Pieces

Just like a great meal, a tentacle is more than the sum of its parts. But as long as the parts are in a bin somewhere - or, more likely, carefully placed on your work surface to keep the sequence - there is still work to be done.

There are a number of glues to chose from. I used ca-glue, but I am comfortable working with it. It can cause problems, so make sure you are familiar with what it can do and how you best apply it.

Here are some considerations for you to make an informed and overall eldritch choice. The most important aspect here is the surface. If you have perfectly flat cut faces (say from the miter saw) you are pretty much good to go anyway. If you have marks or bows that you cannot get out (or chose not to), there are still options.

  • wood glue - This generally gives the best joint between two wooden pieces. In this special case, the main downside is that wood glue requires pressure to give a strong bond. Which is generally easy on furniture pieces but much harder on organic shapes.
  • hot glue - Its main advantage is that it fills gaps really well. So if you have uneven surfaces that would result in little actual contact area after the rotation, hot glue would be my go-to. Just keep in mind that it might not be the strongest glue on this list. I would advise against it on perfectly flat surfaces, though. The small imperfections give it a lot more to grab on to.
  • ca-glue - Here we have by far the quickest glue on the list. You need to work fast, and be careful, because unlike other glues you cannot easily get it off - it is that fast. But it also needs a good contact area to work its magic. For completion's sake, hot glue comes close in terms of speed but is less strong.
  • PU-based glue - This glue foams up and thus fills gaps. I have never had it in my shop so I cannot really say anything about it beyond that. I do believe that it needs clamping pressure just like wood glue, so on that token I would advise against it.
  • contact cement - This I have used but never on wood. It will probably work well and might bridge some gaps, but frankly, I have no idea. I would love to hear your feedback in the comments!

Step 12: Take of the Edge

No matter how you rotate your pieces, you will end up with places where two roughly cylindrical faces meet. Which is a fancy way of saying that it won't look smooth and organic. This is where sanding comes in handy, and it can be done in a number of ways.

  • sandpaper on a stick - Sandpaper is what all this comes down to, and the unpowered, hand-operated version does a good job - it just is not that comfortable. Also, I added "on a stick" because any bent tentacle will have inside and outside corners. While the outside is easy to reach, some inside corners may be prohibitive to flat sandpaper. Hence the stick to wrap it around.
  • bobbin spindle sander - This is basically the aforementioned stick wrapped in sandpaper and powered to spin and bob. This will get everywhere and make sanding easier, but cannot do more than the sandpaper option. Granted, it will do it faster.
  • random orbital sander - My personal go-to powered sander, this one will have a hard time getting into the inside corners as well. So if you do not have a spindle sander, you can use a combination of orbital sander and sandpaper on a stick to get the work done.
  • belt sander - While this is a common tool in many shops, I think it is too aggressive to really work for tentacles that are not at least considerably longer than what I made.

Step 13: Modify It!

Your tentacle is almost done and looks magnificent, mainly because you made it yourself! And you did not even have to sacrifice any part of your soul for it (that you know of). But there is still more you can do to make it more pleasing to whichever timeless overlord you seek to impress (and that includes your spouse).

You should use neither of those two general ideas to change the overall shape of the tentacle. If it does not look the way you expected it to, it is better to make a new one and change the angles you used

  • You can add features - Apply some material on top of that luxurious squiggly shape to make your project look even more organic. Just keep in mind that not all materials play well with wood or glue for that matter. There are 2-component-clays that should work okay for this. I would caution against modeling clays that need to be baked in the oven since the heat might damage the glue bond in your tentacle. A good and often overlooked option is hot glue. Hot glue guns are basically hand-held 3D-printers in that they extrude material that will then harden at room temperature. Perfect for warts and even sucker cups.
  • Or you can remove material - The other option to add more details to your tentacle is to take something away. Again, only use this for smaller details. The best tool here would be a rotary tool with a small grinding bit - I would go with a sphere. This works well to add a number of small divets (as opposed to warts above) to texture any surface. You can also mark the traditional suckers that way. If you are proficient with them, carving into the material with appropriate knives should do the trick as well (even though I would not dare). But speaking of carving, maybe your tentacle has some kind of "battle damage"?

(You probably guessed why this step does not have proper images - because I didn't do that on mine!).

Step 14: Finish It!

By now you should have one or more tentacles ready and shaped in a fashion that pleases you (or the Great Old Ones). But it probably will not yet look the part.

There are too many ways to turn this (possibly wooden) shape into something eerily otherworldly for me to list them all. I write too much already, so here is a list of ideas:

  • paint them - This seems obvious, and it is. Use paint to give your tentacle a base coat and possibly cover up some of its imperfections. You can leave it at a simple color and go with something plain and lifeless, or you can try and add some features to your tentacles.
  • dip them - this works the same way as painting, but might be quicker. No, seriously, with this I am actually referring to using something like latex to give the tentacle a, unexpected and/or different look. Yes, you are also allowed to dip them in paint. I already forbade you to make them from butter. I guess I have to let you do some things. Also, I imagine something like plastidip would work, although I have little actual experience with it and imagine that it would take up a lot of the stuff - and even more overspray.

Step 15: Thank You!

If you stuck with me till the end I hope you no longer feel the need to seek out dying stars to conduct rituals under. Use the "I made it!"-button if you made your own tentacles or successfully managed to summon your eldritch entity-elect without them. If you have questions or more ideas, please post them so I can answer and/or add them here.

Thank you for checking this out, and I hope it inspires you! (And don't forget to vote!)

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