DnA 2-7: Home Explosives Workshop #2
Home Explosives Workshop
Chapter II: Blasting Caps and Better Bombs
Written 4-28-93
By -=Arclight=-
DISCLAIMER: I, Arclight, or anyone else working with DnA cannot be responsible for anything that happens as a result of using these recipes. This is dangerous shit! I advise you not to attempt any of these recipes until you feel totally confident with all the tools, techniques, etc involved. Very bad thing can happen. So if you blow your hand off, or become a Data, I will not be held responsible.
Anyway, on with the show...
Welcome back to another exciting chapter of Home Explsoives Workshop. For those of you that are just joining us, I strongly recommend getting a copy of Chapter I: Low Explosives and the Basics. This will bring you up to speed. Anyway, our topic for today is Blasting caps and better bombs. This will cover what is probably the most important part of this series, how to safely make and use blasting caps (Detonators).
Blasting caps or detonators are small explosive devices that connect to a fuse or electrical circuit and explode with enough force to detonate a high explosive charge. (Unlike Black Powder and other low explosives, high explosives cannot be detonated directly with a -ame.) The caps utilize a small charge of black powder, as an ignitor, and a charge of primary high explosives, which detonates from the black powder ignitor and sets off your explosives.
While I said high explosives cannot be detonated directly by -ame, I should clarify that. There are two types of high explosives: Primary high explosives and secondary high explosives.
Secondary high explosives are the type you usually think of when someone mentions high explosives: they include TNT, Nitroglycerine, RDX, C-4, etc. These cannot be detonated directly, but require a blasting cap.
Primary high explosives are those used in blasting caps and other types of detonators. They are sensitive to shock and heat, and for this reason are used only in small amounts in detonators. They include Mercury Fulminate, Lead Styphinate, Silver Fulminate, TACC (Tetramminecopper (II) Chlorate), and Lead Picrate. These must be handled with the utmost care, as they are so sensitive!
Now that you have some background information, let's take a look at how detonators are made and used.
Blasting Caps
As you have seen, blasting caps are an essential part of any project involving high explosives. While their manufacture is not difficult, it requires EXTREME CAUTION and attention to detail. Unless you'd like to run around the rest of your life with four fingers, having people call you "Cuatro," I suggest you do not deviate in the slightest from these recipes. Mistakes can kill! Anyway, you've been warned.
To begin with, select a clean working area, and assemble all tools/materials needed for the recipe you wish to use. See chapter I for a list of sources. As before, obtain the best grade of chemicals you can find.(USP grade is the best, but ACS is ok.) The first thing you will need to do is make a small batch of the explosive you wish to use in your caps. While there are several compounds that will work, Mercury Fulminate is probably the easiest and cheapest to make. Note that a booster explosive is also required, as it would be dangerous and unreliable to build a cap with 100% Fulminate. Be sure you are ready to load the caps when you make the explosives though, because the they should not be stored for long periods of time.
Mercury Fulminate
Materials:
- Nitric Acid, 90% conc. (Chem. supply store)
- Mercury metal (Chem supply, mercury switches)
- *Ethyl (grain) Alcohol
- Filtering Material
- Teaspoon Measures (1/4, 1/2, 1 teaspoon. S. Steel or Aluminum)
- Heat source (Hot plate)
- Stirring rod/stick
- Water
- Glass containers
- Tape
*Other types of alcohol will not work! If you cannot find grain alcohol, use "Denatured alcohol."
Proceedure:
1. Dilute 5 teaspoons of Nitric Acid with 2 1/2 teaspoons of clean water in a glass container by adding the acid to the water.
2. Dissolve 1/8 teaspoon of mercury into the diluted Nitric Acid. Dark red fumes will appear. It may be necessary to add water, one drop at a time, to start the reaction. Caution: Mercury and fumes are VERY poisonous! Do this outside.
3. Warm 10 teaspoons of alcohol in a container until the alcohol feels warm to the inside of the wrist.
4. Pour the mercury-acid sloution into the warm alcohol. A reaction should begin in less than 5 minutes. Dense white fumes will be given offduring the reaction. As time elapses, the fumes will become less dense. Allow 10-15 minutes for complete reaction. The fulminate crystals will settle to the bottom.
5. Filter the solution through a paper towel into a container. Crystals may stick to the sides of the container. If so, tilt and squirt water down the sides of the container until all the material collects on the filter paper.
6. Thoroughly wash the crystals several times with ethyl alcohol.
7. Allow the mercury fulminate crystals to air dry.
Caution: This is a very shock/friction sensitive high explosive. Handle it with care. Also, store it only in very small quantities and not for prolonged periods of time.
Picric Acid
Materials:
- Asprin Tablets (5 Grain)
- Alcohol, 95% conc.
- *Concentrated Sulfuric Acid
- Potassium Nitrate
- Water
- Paper Towels
- Wide-Mouth Jar, 1pt.
- Rod, glass or wood
- Glass Containers
- Ceramic or glass dish
- Cup
- Teaspoon
- Tablespoon
- Pan
- Heat Source
- Tape
*Not Battery acid! It is not strong enough. Order USP grade conc. Sulfuric Acid.
Procedure:
1. Crush 20 asprin in a glass container. Add 1 teaspoon of water and work into a paste.
2. Add approx. 1/3 to 1/2 cup (100ml) of alcohol to the asprin paste; stir while pouring.
3. Filter the alcohol-asprin solution through a paper towel into another container. *Discard the solid left over*
4. Pour the filtered solution into a ceramic or glass dish.
*5. Place the dish in a shallow pan of hot water and heat it until all the solution in the dish has evaporated into a white powder.
*Note: The water in the pan should be hot, not boiling, approx. 160-180¯F. It should not burn the hands.
6. Pour 1/3 (80ml) cup of concentrated sulfuric acid into a canning jar. Add the white powder to the acid.
7. Heat the canning jar of the sulfuric acid-asprin solution in a pan of simmering water for 15 minutes, then remove it from the bath. The solution should turn a yellow-orange color.
8. Add 3 level teaspoons (15g) of potassium nitrate, in three portions, to the yellow-orange solution; stir vigorously during additions. Solution will turn red, and then back to a yellow-orange color.
9. Allow the solution to cool to room temperature while stirring occasionally.
10. Slowly pour the solution, while stirring, into a jar containing 1 1/4 cups (300ml) of cold water and allow to cool.
11. Filter the solution through a paper towel into a glass container. Light yellow particles will collect on the paper towel.
12. Wash the light yellow particles with 2 tablespoons (25ml) of water. Discard the waste liquid.
13. Place the particles in a ceramic dish and set in a hotwater bath, as above, for 2 hours.
The Picric Acid is now ready to use. It is needed to manufacture blasting caps, as a booster or intermediate charge. As with any high explosive, extreme care must be taken while making and handling it. It is especially sensitive to friction and shock, so beware.
Fabrication of Blasting Caps (Detonators)
Now that you have your Mercury Fulminate crystals and Picric Acid (And you're still all in one piece, hopefully), we'll take a look at how to use it. A blasting cap is a small metal cylinder, usually around 1/4" in diameter and 1-1 1/2" inches long. It contains a small charge of Black Powder (See chapterI), a quantity ofPrimary High Explosive (i.e. Mercury Fulminate), and a quantity of a booster explosive (Picric Acid). Commercial Blasting Caps are packaged in a thin brass tube, with either electrical leads or a fuse hole at the end, for detonation. Note that commercial caps will probably not use the same Fulminate/ Picric Acid combination seen above, as their process has been optimized for mass production and safety.
Commercial Blasting Caps
Electrical Leads
/
Black Powder -ø⁄- Heating coil
| | / |¿Ÿ|/
||/ Primary High ||
Brass case |∞∞| / Explosives |∞∞|
\ |∞∞| / |∞∞|
\ |∞∞| Booster Explosive |∞∞|
\ |≤≤|/ |≤≤|
‘--æ ‘--æ
(Non-electric) (Electric)Improvised Blasting Caps
Materials:
Primary High Explosive (Mercury Fulminate)
Booster Explosive (Picric Acid)
Scale (Weighing in grams, like a dope scale)
Used cartridge cases (Larger than .22 caliber)
Fuse, 12" long
Round wooden stick (Just small enough to fit into mouth of
case)
Drill or knife
Long nail w/sharpened end
Vise
Loading fixture (See below)Proceedure:
1. Remove the spent primer from the case by holding the case in the vise and tapping out the primer with the nail, inserted into the mouth of the case.
2. Use a drill or knife to open up the -ash hole to accomodate the fuse you will be using.
3. Place one end of the fuse in the -ash hole and extend it through the case until it becomes exposed at the open end. Knot this end and then pull it back into the cartridge case, preventing it from falling out.
| |
| | Case
| | /
| |/ Knot in fuse
| Ì | /
‘ ∫ æ
– Fuse (Actually 12" long)
“ /
∫4. Load the cartridge case with .75g of Mercury Fulminate.(No more, no less!) Use a scale, do not try to estimate the amount. A modest investment will get you a good OHAUS scale capable of measuring .1-2000g. Use a piece of folded paper to pour in the Fulminate.
| |
| | Primary Explosive
| | /
|∞∞∞|/
| Ì |
‘ ∫ æ
–
“
∫5. Compress the primary explosive into the cartridge casae with the wooden stick and the following fixture:
1X8X12" (Slot in middle for2X4)
/ 1X8X18"
2X4" 5' board / / Hinge ß
/ › ∫ \ € |
--------------------›---Œ-----------------‡€
› ∫ Support ›-Case € 8"
› ∫ blocks €€€ €
fi€ ->€€€ € |
----------------------------------------------------- ß
|<- 18" ->|
| <- 5 Feet, 1"X12" board ->|Basically the loading fixture is just a long lever, with a hinge on one end and a base. The two vertical wood pieces in front are shields, they protect you in the EXTREMELY likely event that a cap blows up. This aparratus can be constructed from pine or other inexpensive wood, using screws and angle brackets. Note that this operation is the most dangerous in this recipe, and it advised that you were a face shield, or at very least safety glasses when attempting.
6. Add one gram of booster explosive. (Picric Acid)
7. Compress the booster explosive, using the above tools and technique.
| |
| | Booster Explosive
|≤≤≤|/
|∞∞∞|
| Ì |
‘ ∫ æ
–
“
∫8. If the case is still not full, fill the remainder with the explosive to be detonated.
This proceedure, though long and involved, will yield very powerful and effective blasting caps. These are not firecrackers, handle them with the utmost care! They must not be stored for long periods of time, or handled roughly. When made properly, they will detonate almost any imaginable type of charge.
Note that this recipe was an adaptation of that found in The Improvised Munitions Handbook, available at militaria stores gun shows, or from Loompanics Unlimited, as the Black Book series. Other useful titles include Kurt Saxon's Poor Man's James Bond series, and Ragner Benson's Kitchen Improvised Explosives series. Their catalogue costs $5.00 US, and is well worth it. They can be reached at the following address:
Loompanics Unlimited
PO BOX 1197
Port Townsend, WA 98368
Please join us again for Chapter III: High Explosives. So have phun, stay out of trouble, stay aware and informed, and remember: If someone rips you off, don't just take the law into your own hands, take revenge!
{Arclight out}
