Before I say anything else I say this. Pepper Spray like any other weapon is nothing more than a defensive weapon. You cant just go around macing people as fun as that may sound to some of the readers here.
Unless you are getting robbed, beat up or otherwise justified (stopping a heinous crime or felony) there is no reason you should ever dispense this stuff without warrant. In some jurisdictions the use of this may be illegal and for good reason. Do not spray this at any animal unless it is trying to kill you.
Before reading any further let this act as a disclaimer in relation to this post: I am telling you the reader, right now, not to make pepper spray after reading this. Personally I would only ever use this stuff to keep the bugs out of my fruits and veggies. Yep. =) But if you are interested in learning how to do so simply to gain the knowledge then you have come to the right place. If you are asthmatic or have breathing difficulties make this stuff in a well vented area or have someone else compile it for you.
You really only need two things, a way to deliver the spray (delivery system) and a stock of dried pepper/chilli. You can buy the peppers at any local nursery or garden center or just grow your own. The canister (delivery system) can be as simple or complex as you would like (more on that later) and be purchased through a local grocery store on up to Law enforcement surplus.
Picking the right Chilli or Pepper.
The ghost pepper
We base our pepper hotness on the Scoville Heat Unit (SHU) rating system. The system measures peppers on a scale from mildest to hottest.
I would simply use the hottest pepper that is readily available. If you know of any let us know!
At 50,000 SHU to 150,000 SHU we have the Thai Chilli.
Topping the charts are a few burners such as the Red Savina Havanero at 350,000 to 650,000 SHU but to my knowledge the Ghost Pepper is king and the hottest pepper known to man burning everything in its path at a whopping 800,000 to 1,500,000 SHU.
Capsaicin is what we want here when making our pepper spray.
Capsaicin is an active component of chili peppers, which are plants belonging to the genus Capsicum. It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact.From the Wiki.
Most Law Enforcement are issued Capsaicin pepper spray with a payload of 2,000,000 to 6,000,000 SHU. The stuff you buy in the store usually has less than 10% Capsaicin and varies between 500,000 to 2,000,000 SHU.
Delivery System
This can be a simple 3 oz spray bottle from your medicine cabinet or even a empty Windex bottle that can mist or stream when pulling the trigger. You can make larger delivery systems as well that deliver gallons through hand pumps and pressure sprayers used for gardening and weed control but that would also require considerably more pepper/chilli. You can really use anything that sprays.
Part 1. Canister Preparation
Thoroughly inspect your bottle or sprayer for leaks. You want it air tight. Fill it with water and ensure that there are no leaks and that it is dispensing water the way it was intended to. If it leaks in anyway get rid if it and try something else.
Part 2. Things you need
Peppers/Chilli
Rubbing Alcohol (Extracts the Capsaicin)
2 small container
Baby Oil (Ensures the pepper does not break down)
1 clean cloth for filter
1 filter
1 funnel
1 N95 mask or other respirator
Part 3. Putting it all together
3.1 Don your N95 mask. You don't want to inhale anything. Ground up 15 or 20 pieces of pepper with a mashing tool of your taste. Place them into your container.
3.2 Add enough rubbing alcohol until the solution reaches 2cm above the pepper. Stir it steadily for 5 to 10 minutes. Your goal is to dissolve as much as the pepper as possible.
3.3 Add an oz of baby oil into the concoction and stir for a few more minutes. Put a lid on it and shake well. Letting this sit overnight greatly increases the effectiveness.
3.4 Separate the solution form the pepper powder that you could not dissolve. Any impurities may blog or clog the spray. Pour the mixture through one cloth filter (or filter of your choice) into your secondary container. Once everything has been filtered throw away the waste.
3.5 Move your liquid to a spray bottle. You cant use the pressurized cans (single use) to get the long pressurized effect however many many spray bottles use a pump system to spray their contents well enough. And trust me, with this stuff on hand you wont need anything else.
3.6 Go wash your hands and place your solution in the fridge. With the alcohol in it, it should be good for roughly 3 months.
If anyone knows any other recipe let us know in the comment section. Nothing that causes real long term harm or damage. We don't want to maim anyone. If we wanted to do that we would just carry around sulfuric acid or caustic soda. Please don't do that. That kinda stuff kills people.
*You assume all responsibility to ensure you are in accordance with all applicable laws and regulations pertaining to your area.
Cover Image Via PepperWorld / Wikimedia
Source: http://surviveourcollapse.com/diy-how-to-make-your-own-pepper-spray/