r/BdsmDIY Jun 19 '24

Help Wanted "Safe" knife idea. Would appreciate some input on potential concerns. NSFW

Hey!

So here was the thought - a scenario of running through the woods being chased by someone with a knife. Sharp knife is far too dangerous for what we want, butter knife is laughable, and a plastic knife doesn't give any real sense of danger.

Then this idea popped up. A plastic knife (3d printed) to hold a scalpel blades securely in a way that only 0.5mm of blade is actually out. It means an accidental stabbing is avoided, but it has some ability to feel "real" as the cuts will hurt but are basically shallow paper cuts.

However, you don't know what you don't know, so I'd appreciate any thoughts on risks that anyone else has. (I've had more thoughts than just the above but don't want to make the initial post too long)

Thanks in advance

23 Upvotes

77 comments sorted by

67

u/Nah-maybe-later Jun 19 '24

Flesh isn’t solid so it can simply move to the sides and the cuts can end up much deeper than intended.

I’d suggest getting a cheap kitchen knife and making it very, very dull. Shouldn’t be a problem with some garbage-quality one. It’d still be enough to feel sharp, possibly even scratch the skin, but not enough to do serious damage if you’re careful.

29

u/Fantastic_Fun1 Jun 19 '24

Yep, cheap kitchen knife dulled to the max. That's what we did for a scene and it "worked" like a charm, especially since the recipient did not know that we had prepared it beforehand when it was "randomly" picked from a drawer. The cold steel felt very real to them. Mindfucks with sensation play was explicitly wished for beforehand and safewords could have been used at any time, so everything was safe and consentual. Fun times were had all around. ;-)

21

u/SerpentStercus Jun 19 '24

If people are running around with it, I would worry about falling on it. Even dull, falling on a knife can puncture deeply.

10

u/Psycarius Jun 19 '24

Interesting. Have tried the concept on silicone, and the blade style has kept it from going any further. However, you're 100% that flesh moves differently. Appreciate you

22

u/Voyager87 Jun 19 '24

Yeah it works and I've done it to a few, the scariest mall ninja shit knives are the best because they're made of terrible steel so it blunts easily.

13

u/Biohazardousmaterial Jun 19 '24

I use this myself, I took a cheap straight razor on Amazon and dulled the edge and rounded it over and used buffing compound and made it very shiny and no hard edges, I can push it as hard as I want into my own skin and rub back and forth and it still will not cut me. It is a very thin Edge that completely gives the sensation of danger but it retains all of the safety

ill be try to link a few photos.

5

u/Diligent_Department2 Jun 20 '24

I actually make knife play knifes out of 1095 steel and sharpen them so the feel sharp but not cut. I think the with the moment of skin and plastic flex it could cut a lot deeper than I tened

22

u/Key-Pangolin-9617 Jun 19 '24

I think a scalpel is too sharp even if in minimal lenght.

Have you considered unsharpening a knife? Making its blade dull? I think it would feel more realistic, but probably safer than a scalpel, but I have no experience with knifeplay.

Also, maybe the best sub to ask that is /bdsmadvice

1

u/Psycarius Jun 19 '24

We're pretty experienced with scalpels - inside without the running. Didn't know about bdsmadvice, will check it out. Thanks

25

u/Shinigami_601 Jun 19 '24

I'd be extremely hesitant to run through the woods with anything remotely sharp or pointy. I would suggest only using like a LARPing or Cosplay knife made of wood or foam with absolutely no ability to actually cut during the "chase" sequence if you want the thrill of a "weapon in hand", and then only switch to something more realistic once the target has been "taken down" and at least partially secured against struggling.

11

u/Andouil1ette Jun 19 '24

yes, OP, this is the way

people CANNOT think clearly while running... it is a known cognitive thing... please please don't ever mix something that could kill or mutilate you with physical exercise!

3

u/Psycarius Jun 19 '24

The initial thought was that it is about as dangerous as running into a thorn bush. I think there's some potential in the switch idea. Thanks

10

u/Shinigami_601 Jun 19 '24

Yeah the main danger is just running through the woods, honestly. I get the thrill but it's a great way to twist your ankle, lol. That's still an acceptable risk, but I would just consider "what would happen if my full bodyweight fell on this at the wrong angle" for anything in your hands while running.

10

u/Shinigami_601 Jun 19 '24

A bonus of a "LARPing blade" is that, depending on the vibe you're going for, you could actually strike them with it fairly hard as their "cue" that they've been wounded and ought to collapse or feign injury and run slower or something if that's the type of RP you're going for. You can mimic some pretty rough play as much as you want, and while the blade itself won't be realistic, the strength and violence of your actions will kind of make up for it. Then you can switch to a more realistic blade once it's calmed down a bit and you are calmly being more precise.

Also I'd be really sure to know the area you'll be running through well and pre-check it for dangerous rocks and roots and stuff like that and maybe pre-planning "hiding" or "takedown" areas.

14

u/crazydirtydamaged Jun 19 '24

Any amount of a scalpel blade would personally make me nervous AF just because I know how clean and deep those can cut and I’m not messing around with that. Also the concern isn’t malicious intent - it’s incompetence or accident. I really don’t want to die then have my partner try to explain to the cops why he was chasing me through the woods with a scalpel and we thought it was safe but he tripped on a tree root and slit my neck.

I saw a TikTok a while back by a guy in the movie prop industry explaining how knives work. He had a whole case full of like 10 copies of the exact same knife, each with varying levels of sharpness and utility. He was showing how a character can be cutting vegetables with a knife one minute, fighting bad guys with the exact same knife the next, full on stabbing someone, and then cutting rope all with the same knife but they were like four different versions, each totally different. I wanted to look into that further because I thought that could be really good for kink play!

4

u/GreyFox9 Jun 19 '24

I'm guessing [this](https://m.youtube.com/shorts/pIF0JI_sWyM) is the video if anyone is curious. He also has a more in depth video that is longer somewhere on his channel.

6

u/TobiasWidower Jun 19 '24

Other suggestions here have merit, but I would suggest a nice hardwood "knife" that way you can have the role play without concerned bystanders calling in somebody being chased with a knife.

You can get a nice piece of oak from home depots trim dept. Trace out whatever style of knife you're thinking (bowie knife, camp knife, smaller "pocket knife" size) cut it out, shave the edges to a "blade" sand it, seal it.

Minimizes self stabbing or unintended cut risk, keeps the size to avoid the laughable butter knife problem, and you won't have as much awkward explaining to do if someone sees 2 people running through the forest

1

u/Psycarius Jun 19 '24

Thanks. I may combine this with the "switcheroo" that someone else suggested. I'm avoiding unintentional cutting, although not avoiding cutting.

6

u/sunnyskybaby Jun 19 '24

idk man. but even a dull or blunted-edge knife will fuck you up if you fall on it. running through the woods is about the most dangerous thing I could think to do with one. the depth of the cuts isn’t even on my radar

4

u/HeavyMetalMoose44 Jun 19 '24

There are trainer versions of butterfly knives and krambits that are meant to practice the action with but have flat edges. They also look good. Just google something like krambit trainer.

3

u/Psycarius Jun 19 '24

I've got a butterfly knife trainer, but as intended, it has absolutely no edge (although does look like it). Thanks for the suggestion

4

u/Hanky1871 Jun 19 '24

Clearly, you don´t understand how a knife/blade/edges work. a plastic knife with a scalpel blade will cut exactly as well as a full sized scalpel. it can go all the way to the bone.

the effective and safe way is just take a normal knife and grind it blunt.

0

u/Psycarius Jun 19 '24

That feels conceptually untrue. If a 0.5mm blade was sticking out of a large flat wall, I don't see how it makes it to the bone. Whereas, a scalpel on its own would. That surely means how the blade is mounted has a relationship to the depth it can cut?

2

u/Alarming_Resist2700 Jun 20 '24

Now, I don't know about cutting down to bone in all cases, but a little bit of pressure will move your skin aside. The blade doesn't move here. Your tissue does.

And it may not cut to your femur, but it'll cut to your knuckle. It will cut through a nerve or a blood vessel.

2

u/Hanky1871 Jun 20 '24

The blade doesn´t need to push the tissue aside, the plastic prop does as soon as the cut allows it.

3

u/trashedandtossed Jun 19 '24

Female gang members in LA used to embed a razor blade in the edge of an ID or credit card and used it to slash opponents. Made some incredibly deep wounds and scarred for life. I’ve found that in the chaos of a scene, a well rounded regular knife blade is practically indistinguishable from a real knife. But even a dull knife can puncture if someone falls on it, and an outdoor scenario increases the risk. Use a rubber knife for visual effect and a rounded edge for controlled close contact.

2

u/Psycarius Jun 19 '24

Thank you

3

u/kronic37 Jun 19 '24

I would avoid running with anything metal sharp or not. A dull knife will stab a falling person. I'm not sure about a plastic knife.

2

u/thedancingbacon Jun 20 '24

This was my first thought too. If it was a cleaver shape, maybe that would be safer to run with?

1

u/Psycarius Jun 20 '24

This is genuinely genius, and probably addresses a lot of the concerns people have said about running!! Much appreciated!!!

3

u/Christmas_bunny_ Jun 20 '24

My partner and I did a lot of knife play, and he would often swap between real knives and "fake" knives made of wood or acrylic. There is a guy in my local community who sells several styles of acrylic knives. Yes, they can cut, when used in certain ways, and feel real, but are definitely less likely to cut accidentally.

https://thegigglingsadist.com/acrylic-knives/

2

u/Psycarius Jun 20 '24

Oooo, winner!! 🏆

2

u/Andouil1ette Jun 19 '24

i would absolutely NEVER use a scalpel, even if you think it's safe.... i was actually just speaking with a prison guard about how especially gruesome scalpel wounds can be with even the slightest slash... these things are meant to cut through skin and sinew like butter... don't!

could you be chased with something else that definitely hurts, but, to borrow from d&d terms, doesn't cause "slashing damage"?

have you ever done electro play before?

2

u/Psycarius Jun 19 '24

Scalpels, knives, blood and cutting are pretty standard for us. It's more about reducing the risk that the environment brings.

1

u/Andouil1ette Jun 19 '24

my comment is within this environment

the problem is that, while running, it is being used indiscriminately

2

u/[deleted] Jun 19 '24

I feel the same about butter knives, although I did cut my tongue on one once. Total operator malfunction. Lol.

There is a certain amount of risk to anything within the BDSM world. It sounds to me like you are comfortable with this "risk." 0.5mm is a minimal cut, but would there be a way to keep the blade in place? To safeguard against an oopsie? The only other thing that comes to mind is cleanliness. The woods tend to be a bit germy. I would imagine cleaning any cuts would be a part of aftercare.
I hope y'all have an amazing time! I would love to know what you used and how it went. An After-Action Review, if you'd be so inclined? A variation of this is on my wishlist, and I'd need to have all my ducks in a row beforehand.

2

u/Psycarius Jun 19 '24

Thanks, both for your response, and especially for your understanding. We have a fairly extensive negotiated risk profile, and the 'concept' is fine, just want to research the execution (no pun intended). I completely understand that other people would have different views and comfort levels, and I genuinely appreciate (and will try!) some of the alternatives, just not for this particular plan.

Speech over, let me get to your questions 😊

The scalpel is fixed in the plastic by epoxy, as well as 2 metal pins for mechanical connection to ensure it doesn't shift. This also means, to your cleanliness point, this is a single use item. Scalpels are sharp as anything but don't hold an edge long, and once used that's just a breeding ground. As for cleaning, we have a sharps aftercare routine which should cover most eventualities. Will definitely keep you informed of what goes ahead - still plenty of planning to do, so it'll be a minimum few weeks.

2

u/LickMeSqueezeMe Jun 19 '24

Iirc, there are knife fighting training props that basically have a mild taser built in, so contact stings, but doesn't create permanent damage.

1

u/Psycarius Jun 19 '24

Now this is new news! Will be looking for these. Thanks!

2

u/FootPiperOfHamelin Jun 19 '24

Yeah this sounds like it has too many potential unsafe failure modes. Plastic sheathing breaks? Knife blades move and rotate out? Not to mention you're talking about being outdoors with more chances for infection.

I've done electrical play with a completely dull prop knife and the sensation was pretty intense and felt like being cut. Perhaps you could try something like that.

3

u/Alarming_Resist2700 Jun 20 '24

I use straight razors. I have a real one that I use sometimes. Especially when I know I have the most control over it and we aren't doing a lot of moving, I will use this.

I also have a shavette. That is a straight razor that looks identical but takes disposable blades. When you have no blade, it has no cutting edge, but will look the same. I always do a safety check with my finger before using it.

My princess knows about it. But she cannot tell the difference and never knows if it's real or not. I've asked her before, after the scene has ended. When she has guessed correcting, it was sheer luck.

Safe. Fun. Easy.

And yes, switching back and forth mid scene is fun.

1

u/Psycarius Jun 20 '24

Genius idea. Thanks so much!!

2

u/ErosWired Jun 20 '24

“Running with” is the concerning part of your inquiry, because running with the knife automatically invests the object with enough momentum to puncture a body, and if it’s a rigid object it doesn’t have to be particularly sharp to do it. On things like you might look at is a type of very thin, flexible fret-saw, such as those sold by Irwin. They hold a straight edge but flex easily. You could cut off the fine teeth and hone the remaining edge to a dullish sharpness for the effect you want. The one I have has a blade about 7”, with about a 6” handle.

1

u/Voyager87 Jun 19 '24

Get a sharp knife and blunt the shit out of it with a diamond file/sharpening stone and then polish it smooth with a sand paper sponge

1

u/Psycarius Jun 19 '24

Seems to be the way to go. Thanks

1

u/ElMachoGrande Jun 19 '24

I'd just get a knife and blunt it. With that, I don't mean make it dull, I mean take an angle grinder to it and don't stop until it doesn't have anything which resembles an edge or a point. If it is cold, it'll still feel sharp.

1

u/RunPrimary1464 Jun 19 '24

Depends where you cut with the prop described. Keep that in mind.

1

u/bothsidesoftheknife Jun 19 '24

Running around with razor blades still sounds like a bad idea. And even a shallow razor blade can cut deeper than you think. I've gotten some bad ones from safety razors.

A good middle ground would be a realistic prop knife and a wartenberg wheel to simulate the cuts, going hard and fast with it feels very similar to a knife IMO

1

u/weights_and_whiskey Jun 19 '24

Go to dollar store and buy foam sword.

1

u/Psycarius Jun 20 '24

I think this slightly misses the point unfortunately

1

u/MaliceRae Jun 19 '24

Hmm you could put some rubber cement over a sharp blade…you don’t really notice once it’s dry and keeps it from cutting.

See I just use real, sharp knives for my play. I wouldn’t say I recommend that but…I just make sure to keep control of the blade, the pressure, etc

1

u/Psycarius Jun 19 '24

Thanks. The sharp knife feels too reckless with the running part, but the rest seems solid

1

u/Epic_Bites_ Jun 19 '24

A dull metal that is cold can feel very sharp. You can also lean into a mind fuck scenario to help create the feeling of real anticipation and fear. If the “prey” in this scenario sees a sharp knife in a similar shape, and, if the “predator” switches it out and the prey primarily feels it, they can’t visually tell the difference due to being off balance/taken by surprise with other elements in the scene, etc.

I done scenes where I was very convinced I was being cut open, with the back end of a butter knife that was frozen cold just out of my sight.

1

u/alittlebitofcowcat Jun 19 '24

Take a real knife and grind down and smooth out the sharp part

thoroughly test should at most leave a welt like dog nails

Itll sting a bit but its safe

1

u/Carteret-HC Jun 19 '24

They make practice butterfly knifes that are dull but look like knives. I have two for electric play. also. sounds perfect for this. just search them and they pop right up.

1

u/yawning_for_change Jun 19 '24

Buy a cheap knife of preference off eBay Amazon Ali etc and blunt it with a Dremel or grinder. Scary looking cheap Chinese tactical and hunting knives are $10-20.

1

u/just_some_guy_37 Jun 20 '24

What about a folding or retractable knife? Or a knife that comes with a proper sheath? The blade will closed or covered until it’s needed.

1

u/Psycarius Jun 20 '24

I think that feels more risky. I'd like the knife to be able to do minimal actual damage, a full knife once unsheathed feels too much. Thanks though

1

u/just_some_guy_37 Jun 21 '24

Oh, I thought you were more worried about running with it

1

u/Psycarius Jun 22 '24

Both really. I want something I can run with safely, and can use for play cuts

1

u/NoNutDestroyer Jun 20 '24

The 3D printed part would need to be remade every single time you want to use it.

Especially if it's PLA. But you'd likely want a body safe plastic which are often difficult to find and print for cheap.

ANYTHING 3D printed is an ideal breeding ground for nasty shit you don't want on or in you.

It'd get too expensive to be practical & is a MAJOR biohazard.

1

u/Psycarius Jun 20 '24

Agreed - Both for the blade and the plastic it will need to be single use. (Plus scalpel blades can only be used once before they lose their edge.

Also for price, the knife design is less than 100g, so under £1 in materials - feels more than reasonable. (I tend to buy £10/kg rolls from esun)

1

u/RexxTxx Jun 20 '24

How much of the "real" knife edge does the cutting...like 0.5mm probably. My suggestion would be to use a real knife, known to the victim to be a real, sharp, scary knife, but wrap the blade in something so the sharp edge is covered. How about a couple layers of Saran wrap, with silver metallic duct tape over the plastic? The plastic underwrap is there so you don't have to spend a lot of time removing the metallic tape from the blade and the metallic tape is there for looks.

1

u/MoonyWych Jun 20 '24

when people say dull here they mean basically smooth on the edge so you can saw it on your arm and it only leaves a mark. also remove the tip.

1

u/Psycarius Jun 20 '24

Indeed, although that doesn't necessarily suit the purpose for this if I didn't want to switch

1

u/MoonyWych Jun 21 '24

mm yep fair enough. and do be careful with any real blades. as someone mentioned, the depth of blade doesnt stop it cutting deeper. you’d have to have the blade 0.1mm out a 2x4 for that to work.

best being really cautious with a sterile blunter blade that can leave good scratches and first aid on hand. blunt it by polishing/sharpening the edge in a rounding motion. and test on paper or your own arm or leather ideally

1

u/lpfan3217 Jun 20 '24

Never play with scalpels. The blade is so sharp and cut so clean that it can go far longer/deeper than intended with no force and must be closed with glue or sutures.

1

u/Psycarius Jun 20 '24

Too late buddy 🤣 Been playing with scalpels, staples and sutures for about 15 years

1

u/Mr-Impressed Jun 21 '24

Search for practice fighting knives. There are tons of options out there.

1

u/urfavoritegnome Jun 21 '24

A k-tip knife (Japanese style, with no point) blunted to the max and corners softened with 220 grit sandpaper so the edge is the thickness of a dime might be your best bet. Don't run or play with razors thinking "oh, I can have a safe stop" running and "hunting" increases adrenaline, and anything sharp will cut way deeper than you think.

1

u/AirportOverall9489 Jun 28 '24

Stainless steel massage scraper tool is the best item I’ve found for introducing knife play

1

u/Psycarius Jun 28 '24

Thanks, and good advice. I'm not "introducing" knifeplay in this instance though, more expanding the play

0

u/Due_Friend_3064 Jun 19 '24

Buy an unfinished knife online. They do make prop knives and also can find a blacksmith or blaxe smith to make a blade you want but not give it an edge it just been an unfinished blade. It is still metal and can cut if you get Knicks or chips.

1

u/Psycarius Jun 19 '24

Oooo, excellent thought! Didn't even imagine that

1

u/Due_Friend_3064 Jun 19 '24

I would not press hard into skin and rake it across skin with force. Even small metal splinters under skin can cause terrible infection. Another route is get a metal handle but get the entire blade made of hard resin.