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Make a gory Hollywood style bloody knife wound with spine tingling results. Perfect for Halloween or film SFX.

From the Make Halloween Edition by Zack Stern



Step 1: What You Need...

1. Knife. Pick a cleaver style knife with a decent sized blade.
2. Small diameter plastic or vinyl tubing
3. Baby medicine dropper or turkey baster
4. Hot glue
5. Dremel or grinder

Step 2: Prepare the Knife...

Make a measurement of your forearm by holding the knife down on your arm (CAREFULLY!). Make two marks on both sides of your arm and then draw a rough arc.

Step 3: Make It...

Put the knife in a vise or use clamps to hold it down firmly. Once secure, begin cutting the arc using the tool of your choice. I used a Dremel and was surprised that one cutting blade made the entire cut.

WARNING: Be sure to wear safety goggles and gloves.

Then using a grinder or file, flatten out ALL of the blade edges and corners. Carefully test it with your finger to make sure it is not sharp. We don't want to draw real blood.

Using hot glue, secure the tubing to the blade. You may want to test the blade on your arm for the best location of the tubing so the 'blood' squirts out at the right spot.

Step 4: Use It...

Make some fake blood or buy a small tube of it. There a quite a few recipes for fake blood on the internet if you want to go the hard way.

This effect works best with long sleeves. Run the end of the tube up your sleeve and down your shirt or jacket. Suck up some blood using the medicine dropper or baster and attach it to the open end of the tube. Your hollywood effect is ready to use.

Lay the knife down on your arm and slowly squeeze out the blood as you make a spine-tingling scream!

I hope you enjoyed this Halloween SFX Instructable!
<p>just kidding !!!!!!</p>
<p>i hate it</p>
AAUUUGHHH!!! I forgot to cut out the arc in the knife!!!... ... (*tears) I want my arm back...
...Just Kidding 5 stars
LOL!!!!
do you know how hard it is to cut through hardened steel? not all people have diamond-coated dremel bits
You can make a pretty realistic knife from duct tape, so there's always that.
uhh yeah, but they are $7 on ebay. a simple 2 second google search proved that.
Wow really there are diamond coated bits?
Oooh. I want one<br />
Yeah :D<br />
i might just make the knife part and put it on a dummies neck (my brother maybe?)
&nbsp;It would've been better to make the whole knife out of wood and hide the tubing in the handle. thats only if you want it to be shown on both sides.
lovely pick of knives if you can cut through the whole thing with one blad roflmao<br />
7@7 4 1337 kr3w
This is very excited.
have fun cutting through hardened steel with a dremel ; )
I think its cool, but can't see this being used in a Halloween costume. you need to secure it to your arm. to me it also seems inconvenient, if not impossible to collect Halloween candy while holding that thing up to your arm.
A good job and well explained instructable! In my opinion "Tech" section is not an apppropriate classification. The content is not "Tech".
Couldn't you just use a plastic knife that looks realistic? Or mod it to look realistic?
Just to safe some google search: Fake blood: Water+Cornstarch+Food coloring ( works for me )
Maybe it's a good idea to dull the blade with the Dremel before doing this...
Step 3, third paragraph - <em>dull all the edges</em>.<br/>
ah yes, but step 3 is AFTER you've put a sharp cleaver to your arm to mark the cut out part... i would dull the blade before putting it on my arm... but then again, scars like that are cool..
I think, if somebody is daft enough to cut their arm at the preparation stage, then they probably shouldn't be allowed sharp things anyway.
true true :) but there's probably a lot of them out there, more then you and i both might think :)
Lol
Hehehe... Nice effect
in the movie, you looked at a different arm then was shown. lol, anyways, cool!
it almost made me faint! Looked real.
..."and now back to Cannibalistic Chefs on FOX"
teehee
how much did this build cost?
I enjoyed the bad jokes and cheezy facial expressions - they made my day :-)
simply, awsome
haha i got paint on my leg and my mom thought it was real
Lol, awesome FX )
Haha cool ! one question, how do you pump the blood if one arm is being cut and the other is holding the knife?
Squeeze with your armpit. he he.
Your thumb holding the knife squeezes the bulb.
This was also in Make: Volume 9 FRINGE.
This is Awesome! hehe, nice face there at the beginning of the video KipKay =P<br/>
ooh <br/><br/>deviously nasty =D<br/>
I love it KipKay! Great idea!
Another great one! Next you need to make then that can be secured to ones arm as part of a costume.

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