“4-ounce” rockets? What does that mean? Well, if you’re interested in the history of the term and some further background information on rockets in general, you can find it in the Introduction to Rockets article. But if you’re more interested in getting started, let’s go!

Specifically, in this project we are going to make a 4-ounce (1/2-inch ID), nozzled, cored, stick-stabilized, black-powder skyrocket with a bag-shell heading.

Here’s a diagram. You’ll see references to it throughout this project.

Black Powder Rocket Diagram

Half-inch rockets are small enough that they don’t use huge amounts of materials. They can be made quickly, and can be flown in many back yards.

But they are large enough to be really impressive, with that black-powder-rocket “whoosh”? as they launch. They can also carry a nice payload of stars or other garnitures into the air. Working with them will provide plenty of experimentation, experience, research and development, and plain old fire-working fun. This is one “Quarter Pounder” you won’t have to drive to McDonalds to get!

Continue Reading: 4-Ounce Black Powder Rockets…

4-Ounce Black Powder Rockets is a post from: Confessions of a Fireworks Man

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This nifty new project shows you two methods for making mines.

To make this project, you need:

• The supplies shown in the project below.
• Black powder, which you can make or buy locally. If you want to make your own, check out the Red Gum Black Powder project.
• Stars. This particular mine is small, and uses 3/8″ stars. The two projects for making Rubber Stars are perfect for these, but any small stars will work.

The mortars you use for your mines need to be securely anchored to the ground in some way. So, you might want to check out these two links on setting up mortars for a consumer fireworks display.

Have fun. This is a fun project to make a spectacular kind of firework that many people in your fireworks display audience have rarely, if ever seen. You’ll be a hero.

–Harry Gilliam

Making 1.75-Inch Bag & Piston Mines

By Ned Gorski

Introduction

In its simplest form, a fireworks mine is a device which shoots a spray of stars skyward from ground level. This dramatic low-level effect, complementing and contrasting with high aerial shells, can lend welcome variety to any fireworks display.

Mines can be used to augment the beats in music. Many mines spaced out across your firing area may be fired simultaneously in what is called a “mine front.” Or they can be fired in rapid sequence down the line from one side of the field to the other in what is called a “mine run.”

These mines are quick, easy and inexpensive to make. So, many of them can be made to provide more devices for a show–and homemade devices at that!

Fireworks Mines

The construction of these mines and the equipment used to fire them can vary considerably, and many different effects can be created. For example:

• Standard length mortar tubes will fire tall, narrow sprays of stars. Short mortars will create short, wide star-sprays.
• Fast burning stars will create vertical rays of light which burn out at the top. Slower burning stars will arc over, creating gracefully drooping spark displays.
• Other inserts besides stars may be used in mines. Small homemade devices or “repurposed” consumer fireworks devices such as hummers, bees, whirlwinds, and reports, as well as flying-fish-fuse, and go-getters may be used, either individually or in combinations with each other.

The mines we are about to work on are impressive fireworks devices, while still being in the “consumer fireworks” size range. So while they present plenty of opportunities for experimentation and creativity, they are also suitable for a basic, backyard fireworks display.

Continue Reading: Making 1.75-Inch Bag & Piston Mines…

Making 1.75-Inch Bag & Piston Mines is a post from: Confessions of a Fireworks Man

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Introduction

The “rainbow” of star colors I’ll be discussing here builds on the methods detailed in the How to Make Screen-Sliced Brilliant-Red Rubber Stars project to expand your color palette of star choices.

Note: Be sure you learn and are familiar with that new way of making and priming stars before starting on this project!

The screen-sliced rubber stars production method has significant advantages for the small-scale hobbyist:

• A full range of great colors with a small collection of chemicals
• Simple and fast star-making process
• Fast drying stars, which are great for on-site pyro-device manufacture
• Very specific quantities of stars can be made, minimizing storage of excess stars
• Matching-color rising tails for shells and rockets can be made at the same time as the stars
• Metal particles may be added to the stars to create spark-trails behind the color-star heads

The introductory project focused on one basic star formula for “brilliant red” stars. At some point most fireworkers start to yearn for a wider variety of color stars and effects. They want to fill out the palette of potential star effects they have to choose from when making fireworks devices. Multiple colors and effects used in the same device, as seen in the photo below, can really make for interesting and beautiful fireworks.

A Pair of Amateur-Built “Stained Glass” (or “Kaleidoscope”) Shells
Photo by Tom Handel

So how do you make a rainbow of color stars to go with those charcoal stars and glitter stars, silver-spark tailed stars, or a nice white star? At the same time, can we get around the problems of using chemicals that are hard to obtain or require special drying?

The purpose of this project is to answer these questions with a set of well-balanced color star formulas that use easily available and relatively non-hygroscopic chemicals. These formulas are designed to work well with the screen-slicing method described in How to Make Screen-Sliced Brilliant-Red Rubber Stars.

Now if I were you, I’d be clamoring to get my paws on those formulas and itching to start getting my hands dirty right away. So, I’m going to give you the table of new formulas right up front. Your job for this project is to use these new formulas along with the screen-slicing process you learned in the red rubber stars project to make some of these beautifully colored stars and try them out.

However, when you’ve worn out your hands (or exhausted your pyro budget), come on back in here and read the two sections of this project that come after the star formula table below.

In the first one, “Pyrotechnic Color,” I’ll explain how these (and other) formulas work to create colored flames and how you can mix and modify them to create even more colors for your pyro palette.

Finally, in “Developing a System of Bright Stars using Carbonates,” I will show you how to approach a major pyro research project by explaining how I went about developing this one. In doing so, I’ll include many more useful color star formulas for you to try and experiment with.

Continue Reading: How to Make a Rainbow of Colored Screen-Sliced Rubber Stars…

How to Make a Rainbow of Colored Screen-Sliced Rubber Stars is a post from: Confessions of a Fireworks Man

At a certain point, whether for fireworks aerial-shells, mines, roman candles, or rocket headings (or all of these), you’re going to need stars, and lots of them. In addition to spark-producing charcoal and glitter stars, you are going to want to be able to produce brightly colored stars to enhance and add variety to your pyrotechnic palette.

In this article, I’m going to get you started down this path by showing you a simple, easy-to-master technique to make brilliant red stars without any special or expensive equipment. These stars are ready to test in minutes, and dry and ready to use in just a few hours.

This is a breakthrough method of making stars. And I don’t say that lightly.

Why? What makes the screen-slicing method so special?

• Simple equipment: All you need is a screen. Forget about expensive star rolling machines, loaf boxes for making cut stars, and tricky-to-use star pumps, and plates.
• Cheap: A framed screen can be had for $30 or less.
• Fast: You can test your stars as soon as they are made, before they are dry. And star drying time is a couple of hours, max.
• Easy: Absolutely no special skills are needed. If you can play pattycake, you can make these stars. And they are almost impossible to screw up.
• Water Resistant: These stars are water resistant. You can store them longer.

Whether these are the first stars you ever make, or even if you are a seasoned fireworks veteran, screen sliced stars are faster and easier than any other star you can make.

–Harry Gilliam

Introduction

There are an almost infinite number of colored-star formulas out there using a wide array of different, sometimes difficult to find chemicals. In this project though, we’re going to focus on a simple, four-chemical formula which uses commonly available materials. The red formula we’ll start with here, called “brilliant red,” is about as eye-catching a star formula as there is, showing up well even if it is shot during the daylight. When folks call this star “brilliant,” they mean brilliant. I won a best-red-star competition at a large regional fireworks-club event one year with this star.

Among all the different methods that can be used to make fireworks stars-cutting, rolling, pumping, pressing the composition in tubes for box-stars, layering composition between sheets of paper for falling-leaves stars-each method has its advantages and disadvantages, and is appropriate in certain situations. The method I will show you here, screen-slicing, may be the fastest, simplest, and easiest way to produce a finished batch of color stars ever invented.

In this particular project, stars will be sliced through a 3-mesh screen which has three openings per inch (nine openings per square inch). The individual openings in such a screen are about 5/16-inch square. A 3/16-inch thick patty of star composition will be pushed through that screen to cut the patty into cubic stars. Since the composition extrudes through the screen openings as it is forced around the relatively large screen wires, the stars end up being about 5/16-inch thick.

Once these stars are primed using the process described below, they end up being almost spherical and about 3/8-inch in diameter. This size is nice for rocket headings, mines, and aerial shells in the 1.75-inch to 4-inch range.

Using a larger 2-mesh screen (four openings per square inch) and a thicker patty (say 5/16-inch thick), and using more composition per patty (say 24 ounces) will produce finished stars in the 5/8-inch diameter range. These stars would work in 5- to 8-inch shells and devices.

Some advantages of this rubber-bound formula and manufacturing process include:

• Even before drying, these stars can be test-fired out of a star gun immediately after production to check their color. After 2-3 hours of drying in a warm breezy location or in a drying chamber, these stars are ready to be used in devices.
• These stars are relatively water resistant, with no water used in their manufacture. They are rubber-bound, which inhibits water absorption by otherwise hygroscopic chemical ingredients such as strontium nitrate.
• Rising tails for rockets or shells which exactly match the color of these stars can be manufactured at the same time the stars are made.
• Different varieties of colors and effects are possible using this method. More colors and effects will be presented in a follow-on project.
• Particles of metals such as titanium or ferro-titanium may be added to the color composition to create a silver-spark trail behind the burning colored star.
• You can produce just the right quantity and size of these stars for a particular size shell or other device, so you’ll have no leftover stars requiring magazine storage.

All of these attributes make these stars ideal for on-site manufacture at fireworks events where devices are made from scratch in a limited amount of time, and where no excess stars requiring transport and storage are desired.

Acknowledgements: Troy Fish, in Pyrotechnica VII, authored a detailed article on rubber-bound stars, “Green and Other Colored Flame Metal Fuel Compositions Using Parlon.” This article has inspired many explorations into this rubber-star-binding process, and recently Gary Smith has shared his experiences with one variation on this process, the screen-slicing method of cutting these stars. Without these two sources of inspiration, this current project would not have been possible.

Continue Reading: How to Make Screen-Sliced, Brilliant-Red Rubber Stars…

How to Make Screen-Sliced, Brilliant-Red Rubber Stars is a post from: Confessions of a Fireworks Man

Click here: TultepecFireworks

A whole buncha my pyro pals from the Florida Club are down there as I write this. And I am NOT.

I HATE when that happens!

Enjoy the video. And tell me what you think of it.

Harry

Insane Fireworks in Tultepec is a post from: Confessions of a Fireworks Man

Reducing particle sizes is commonly done with thumb and forefinger, screening, blade milling, ball milling, and more exotic and expensive alternatives. Each has its pros and cons.

A blade mill is a cheap chemical grinding mill, available everywhere, and incredibly efficient and fast. They are not suited for grinding large quantities of stuff, but for a pound or less of a single chemical, they are hard to beat. They mill faster, and are quick and easy to clean up. Bigger, ball mills have a place, too. Eventually, you will want to have both.

A spinning blade-type coffee grinder is what I use. They’re cheap, and available at Walmarts everywhere in several models. My advice is to get three. One for oxidizers, one for everything else, and a backup. Look for simplicity. Higher cost is a waste of money. Cheap and simple is best. Avoid tops that are tricky to get on and off, or having locking mechanisms on them.

How to use a blade mill. Use them this way and they will last and last: Put your chemicals into the mill. Put the top on, and holding the mill in your hands, off the table, turn the mill on and off intermittently for a few seconds at a time while you shake the mill at the same time to really circulate the material around inside.

How to burn out your mill. Turn it on and leave it on for a few minutes. It’s simple and foolproof. You can reliably burn it out every time this way. The most common reason blade mills burn up is the way they are used. I have two (out of 3 purchased originally) that have been used regularly for nearly 15 years. Cost me $12 each at Walmart.

The secret is not to leave them running very long. I run mine for very short periods, 15-30 seconds max, shaking the grinder at the same time it is on. Then I shut it off, and repeat the process *IF I HAVE TO*. Which I almost never do. I don’t get much additional reduction in particle size after 30 seconds of milling.

How to grind a lot of chemicals fast: I can blade mill a pound of potassium nitrate rocks into fine fluffy powder in 5 minutes or less. Just use small batches in your mill. Be sure and shake the mill at the same time you’re milling the powder. It speeds up the process and you can actually hear the coarse particles getting smaller. Don’t try and put too much in at a time. Smaller batches mill up faster. Bigger batches bog the mill down and slow the process.

Cleaning blade mills: Dump and tap as much powder out as you can get out that way. Then use a paintbrush to get down into the mill and the top to remove the rest. Remove everything you can see. The tops can usually be run through a dishwasher, but be sure they’re completely dry before reuse. The base unit with the motor cannot be submerged, but you can certainly use a damp cloth on the inside of them.

Lifetime of a blade mill: Mills used for oxidizers will break sooner. The corrosive action of the oxidizer dust will eventually kill the little mill. Not to worry. You have a spare.

Milling fuels and oxidizers together. You can only do this once. If you survive the first attempt, you will certainly never do it again. Depending on the reactivity of the particular chemicals you’re trying to mill together, your injuries may range from bad burns to death. Never attempt to blade-mill oxidizers and fuels together.

Tell Me What You Think: Was this Article Helpful to You or Not?

Just leave a comment below. Thanks.

- Harry

Fireworks Chemical Milling – Fast is a post from: Confessions of a Fireworks Man

Here’s your link for Turbo Pyro:

http://www.turbopyro.com

———————————————————————-
I DON’T KNOW WHETHER YOU HEARD THIS YET
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I’ve added *more* stuff to Turbo Pyro. I want to make sure you have fun with your projects, so I added a bonus Smoke Bomb Kit and project–Making Jumbo Smoke Canisters eBook (including videos).

Be sure and get online fast and place your order. Again, there are only 400 Turbo Pyro Supplies Kits available.

Grab yours here:

http://www.turbopyro.com

P. S. You get instant access to the Turbo Pyro eBook and the Smoke-Making eBook right after you order.

P. P. S. Be sure ahead of time your credit card has enough $$ left on it to make the charge. Otherwise you may miss out. (V, MC, Amex, Disc.)

Harry

Turbo Pyro goes LIVE at 12:00 Noon Eastern time today, June 19th is a post from: Confessions of a Fireworks Man

We’re getting very close to releasing Turbo Pyro this week.

Here’s some info on 2 new bonuses I have added to the Turbo Pyro Supplies Kits, as well as some tips on getting your order to go through on product launch day.

Early Bird Bonus #1-limited number: If you are one of the first 75 people who buy the Turbo Pyro Supplies Kit, you’ll get a free copy of the North American Fireworks Trade Directory, a $44 value.

The Trade Directory lists all of the important fireworks related companies on the continent. This included importers, distributors, wholesale/retail, manufacturers, consumer fireworks, special effects, display fireworks, consultants, companies who offer shooter training, attorneys, display shooters, clubs, shooter training, trade associations, fireworks transportation, fireworks insurance, publishers/booksellers, lab services, customs brokers, and suppliers of everything pyrotechnic you can imagine.

This is a book everyone in fireworks should keep on hand forever. If your order arrives without one of the Trade Directories, it is because we ran out before your order was placed. Sorry, we don’t have but 75 of these.

Bonus #2: Colored Smoke Bomb Kit, a $60 value. You get a complete kit containing smoke mix, potassium chlorate oxidizer, tubes, end caps, fuse, and a new smoke bomb project written by Ned Gorski, never published before. This project and kit give you step-by-step instructions for making up to 20 big, fat smoke canisters.

Great for daytime effects. Definitely a step up from the consumer smokes you’ve probably seen. Very easy and fast to make. The chemicals and supplies for this one will be included in your Turbo Pyro Supplies boxes. The project, “Making Jumbo Smoke Canisters,” will be available to you as a free downloadable .pdf document.

More about the Turbo Pyro Supplies Kits. Once you order your Kit, it will be shipped from Skylighter right away. We want you to have them as soon as possible before the 4th of July. The kits are shipped in two boxes. They have to be shipped that way to keep oxidizers separate from flammable items. Since both boxes contain hazardous items, they have to be shipped by US Mail Parcel Post. Occasionally, the post office will not deliver both boxes on the same day. Please be patient. The second box will arrive.

The Turbo Pyro eBook. Once you order your eBook, you will be given instructions on downloading it. It is a big file, over 10 megabytes. You will want to use the fastest Internet connection you can get. It cannot be emailed to you. The book comes in Adobe .pdf format. Sorry, no other formats, and no printed versions are available. Please read Chapter 1 immediately for more information about using the book, and playing the videos.

How to Order Turbo Pyro. If you are on our mailing list, you will receive a notice telling the exact time the link to the Ordering page will open.

When that time comes, as quickly as you can, go there and place your order. You will not see the familiar Skylighter.com shopping cart. Don’t worry. Just follow the instructions onscreen and place your order as quickly as you can. Please do not start an order and not finish it; you may lose your chance at the book and/or the Kit.

We cannot predict how many people will be trying to get through the same process at the same time. You may experience delays. Just keep trying. Have your credit card ready before you start.

Your credit card will not be charged at the time you place your order. We will charge your card on the day we actually ship, which will most likely be this Friday. You will be emailed a shipping notice and tracking number at that time. So be sure you whitelist any Skylighter.com email, to be sure and receive your shipping info. Your card will be charged the exact amount showing on your receipt. It would be a good idea to print that out and keep it.

That’s about it for now.

Harry Gilliam

2 New Bonuses Added to Turbo Pyro is a post from: Confessions of a Fireworks Man

In my experience, there are three basic machines, which become necessary as one gets deeply into fireworking: a ball mill, a star roller, and a hydraulic press. Ball mills were discussed extensively in Fireworks Tips #91, and I showed some options for star rollers in #92. Now it’s time to look more deeply at rocket presses.

Commercial Rocket Presses

In past newsletters I have shown several of my hydraulic presses in action as I’ve made rockets, comets, pressed stars, black powder pucks, or fountains.

Some devices, like simple gerbs or black powder rocket motors, can be made by simply hand-ramming them with a rawhide mallet and a pounding post. Or they can be pressed with a hydraulic press.

Other devices such as whistle rockets or strobe rockets utilize more sensitive fuels, and require hydraulic pressing for their manufacture. Hand-ramming these motors is simply asking for a disaster.

Since I’m about to present projects showing how to make whistles, whistle rockets, and strobe rockets, I thought an introductory essay on hydraulic presses would be in order.

In the previous articles mentioned above I’ve shown my small Hobby Fireworks press. It’s a nice press and was not too expensive. It sits on top of my workbench and is light and portable. I can take it to club events like the PGI convention. Unfortunately, Hobby Fireworks has gone out of business.

Over the years I made some modifications to the press so that it suited my needs better. I replaced the 1/4-inch-thick steel plate on the top of the bottle jack with one that is 3/4-inch thick. The thinner one started bending a bit, and I want that plate to be perfectly flat.

I replaced the original 4-ton bottle-jack with a fast-action 6-ton one. The new jack can exert forces up to 12,000 pounds, which is about all I ever need, even when pressing large 4-inch comets and large rockets. Additionally, the new jack raises very quickly compared to standard-lift models.

The jack is available at Northern Tool, and currently it sells for $28, including a nice, collapsible lug wrench.

When I showed an advance copy of this article to my friend, Dan Creagan, he sent me a photo of a jack he had just found at WalMart, apparently identical to this one except it was painted black and had the Torin Brand name on it. It only cost Dan about $19.

I had the welding shop reinforce the press’s adjustable cross “bridge” so that it would withstand the additional force exerted by the 6-ton jack.

I drilled holes in the back of each horizontal leg-support so that I could bolt the press down to the workbench to secure it during use.

The pressure release knob had a hole drilled through it and a 3/16-inch rod-handle installed for fast and easy operation.

This press has gotten a lot of use over the years, and if I had welding capabilities and I wanted a nice little press, I’d duplicate this model.

There are H-frame shop-presses available at various suppliers. In the past I’ve referred to one such press sold by Greg Smith Equipment. It’s a floor standing unit, and weighs over 150 pounds, but it looks like a pretty nice press, has a good range of adjustability, comes with a pressure gauge, and sells for only slightly more than $200.

Simple Do-It-Yourself, Hydraulic Press

Note: My friend, Jim B, has a favorite saying; “For every 10 pyros, you’ll get a dozen different ideas on how to do any task in pyro.” The ideas I present in the following project are designed to simply get your creative juices flowing. I seriously doubt anyone will build a model that is exactly like mine. But maybe these ideas can point you in the right direction.

In addition to the commercially-manufactured options described above, I got to thinking about a sturdy, relatively lightweight, bench-top press which did not require much welding. I’ll describe one possibility that came to mind.

The setup and operation of the hydraulic bottle-jack is similar to the Hobby Fireworks press. I had six, 4×4-inch, 3/4-inch-thick, steel-plate shims cut at my local steel supply, to augment the adjustability of the press. Between the 5.5-inch travel of the bottle jack’s piston, and the 4.5-inches of adjustability the shims provide, the press has a total of 10 inches of travel between all the way down and all the way up.

This allows me to adjust the press’s top plate with the hex-nuts only one time per the particular device that I’m pressing. I never needed more than that 10 inches of adjustability for any of the devices I make. I’ve tripled-up the top hex-nuts because of the forces they endure during pressing. I don’t want to be stripping any threads.

The Press’s Main Frame:

The main frame of the press is made from four 3/4-inch x 36-inch threaded rods, nuts and washers from Home Depot. I had my local steel supply-house cut the bottom and top plates, which are 12-inch long pieces of 1-inch (thick) x 9-inch steel plate.

One-inch-thick steel plate is obviously very strong, and that strength is necessary to withstand the forces, which will be involved in pressing fireworks devices. I wouldn’t want to use steel plates that are thinner than the ones I used, and I also wouldn’t want to make them larger and spread the threaded rods out farther. This could lead to bending the plates.

The PVC plumbing pipe sections on the threaded rod uprights are there to keep me from cutting my knuckles on the threaded rod as I insert and remove devices in the press.

Installing a Blast-Shield

When I’m pressing whistle or strobe rocket motors, which use pressure sensitive, powerful fuels, the installation of a blast-shield is a good idea. The 1/2-inch thick plastic sheet will offer some protection just in case a motor “goes off” while it is being pressed.

The blast-shield is attached to the press and held in place with 3/8-inch eye-bolts, large fender washers, and hex nuts. Polycarbonate plastic such as Lexan is used in bullet-resistant windows, and serves well for blast-shields.

The other benefit of the PVC pipe on the threaded rods is to hold up the bottom blast-shield, eye-bolt supports.

Jack Return Springs

The two 7-inch springs, also from Home Depot, serve to return the bottle jack to its “down” position when the pressure-relief valve is opened. The top of each spring is attached to the 4×4-inch plate that is welded to the screw-out jack-post. The bottoms of the springs are attached to eye-bolts that are mounted in holes drilled through the bottom steel plate.

I had my welding-shop weld on small hex nuts for the top spring attachment at the same time they welded the plate to the jack post. This was the only welding required in this project.

Pressure Relief Valve Handle

To create an easily-operated handle for the jack’s pressure-relief valve, a hole was drilled through the end of the relief valve. A piece of 3/16-inch galvanized steel rod, bent in an L-shape was inserted through the hole, and the small end was pounded flat on a vise-anvil to hold it in place.

Holes in the Steel Plates

The holes in the top and bottom steel plates were drilled using a drill-press. That was the only large piece of equipment that was necessary in the fabrication of the rocket press. The threaded-rod holes were drilled at 9.5-inch centers, side to side, and 5.5-inch centers, front to back.

The jack is attached to the bottom plate with three, 5/16-inch bolts, which go up through the steel plate and into holes I drilled and tapped in the bottom of the jack. (Threading holes in metal is done with a tool called a “tap.”)

Two extra holes were drilled toward the back of the bottom steel plate, through which bolts will go to attach the press to my workbench. This will make the press nice and steady as I’m pressing rockets.

I used a hand-held grinder to smooth all the edges and corners of the steel plates. Then I primed and painted the plates using spray primer and finish paint.

Hydraulic Pressure Gauge

There are a few pressure-to-force (PtoF) hydraulic pressure gauges available to the pyro-hobbyist community. These gauges employ a one-square-inch-area piston, so they directly read out the number of pounds of force being applied to the item being pressed.

For example, if the PtoF gauge is reading 2000 psi, the actual force being applied to the tooling is 2000 pounds, the equivalent of 2000 pounds of concrete sitting on top of the tool.

An advantage to using one of these gauges is that you won’t need to install a pressure gauge on the press’s bottle jack.

I personally like to use a gauge that is actually installed in the bottom of the bottle-jack. Doing so enables me to eliminate one loose, movable component, like the PtoF gauge, when I’m aligning and pressing devices in the press.

Using a gauge on the jack, though, requires that the gauge’s reading be multiplied by the area of the jack’s piston, in order to determine the actual force being exerted by the jack. I’ll show what that means in a minute.

Installing a gauge on the bottle-jack presents what is probably the most challenging aspect of this project–drilling and tapping/threading the bottom of the bottle-jack, and installing a hydraulic pressure gauge. But, it’s good to know how to do this, even if a PtoF gauge is going to be used.

Installing a gauge on a bottle jack requires the partial disassembly of the jack, drilling a couple of holes, tapping/threading the hole where the gauge will be installed, cleaning debris out of the jack, and reassembling it.

One of the nice things about the bottle-jack I’m specifying in this project is that it is relatively easy to take apart and put back together.

First, the rubber drain/fill plug on the back of the jack’s cylindrical body is removed, and the oil that fills the jack is emptied into a clean pot. This oil can be filtered through a coffee filter and reused in the jack when it is reassembled.

When draining the oil, it helps to remove the pressure-relief valve. This valve has a 1/4″ steel ball bearing down in the hole into which it is screwed. Carefully set the ball and valve aside, and finish draining the oil. Pumping the lever assembly a few times works the rest of the oil out. Now is a good time to drill the hole in the pressure-relief valve and install the L-handle.

The lever-arm has a couple of steel pins, held in with spring-clips, and is easily disassembled. (You are making mental notes of how all this goes back together, right?)

It’s time to remove the large hex-nut at the top of the jack now. This requires that the base of the jack be held securely in a vise or a rocket press. (Waitaminnit, I’m making my rocket press! How can I hold the jack in my rocket press? I have 3 presses, and this will be my fourth.)

The hex-nut is then loosened with channel-lock-pliers or a large pipe-wrench. It may be necessary to whack the wrench with a rubber mallet or similar heavy object. The nut is screwed off when it is loose, and the central jack piston and outer jack shell-body can also be removed. The nut has a plastic O-ring gasket on it where it hits the main body, but this gasket is usually “glued” on with paint and does not need to be removed.

There is a “tapered” large rubber O-ring which sits in the groove that the shell-body came out of. Remove this O-ring. Remember that it was in there with the thin edge up, and the wide edge down.

Inside the jack, there will be a small, wire-mesh filter shoved in one of the holes in the base. Make a note of which hole it’s in, and then remove it. Actually, this is a good recommendation, which has never worked for me in real life. Each time I’ve disassembled a jack, the filter has dropped out before I get to notice where it was in the first place. I’m not sure how they get the darn thing to stay in during shipping and/or operation.

I’ll show in a moment how to determine which hole the filter ought to go back into when the jack is reassembled.

The screw-post will only unscrew so far as it extends out of the jack’s piston. It is not necessary to remove this screw-post all the way. The whole jack can be taken to the welding shop when the 4×4 plate is welded to the screw-post. If one wants to remove the post all the way, some filing/grinding is necessary to remove the small “indents” which have been knocked into the top of the cylinder to hold the post in place.

Now is a good time to measure and make note of the diameter of the bottom of the piston. In this case it measures 1.375 inches. Squaring half that diameter (the radius) and multiplying that by Pi (3.1416) yields an area of the bottom of the piston of 1.5 square inches. (3.1416 x .6875 x .6875 = 1.5 square inches)

Because of that, when my new, jack-mounted pressure gauge is reading, say, 1000 pounds-per-square-inch (psi), I’ll multiply that gauge’s reading by 1.5 to determine the actual amount of force the jack is exerting on the tooling in the press, which in this example would be 1500 pounds.

Once again holding the base of the jack in a vise or rocket press, I now carefully use a pipe wrench to loosen the jack’s inner cylinder. I apply the wrench right down at the bottom of that cylinder in order to avoid crushing or distorting the tube as I loosen it.

Once the inner cylinder has been removed, another plastic O-ring gasket can be seen inside the base where the cylinder bottoms out. This O-ring does not need to be removed. Notice that there is a top and a bottom to the inner cylinder. The top is beveled on the inside lip to make insertion of the piston easy. The bottom has a flattened edge, which bears on the O-ring seal.

The small lever-operated jacking piston/cylinder should also be removed at this time. There is a metal washer and a 1/4″ steel ball down in the base’s recess which should also be removed.

And, now, finally we’ve arrived at the final disassembly step. There is another 1/4-inch metal ball in the bottom recess of the base, held in with a plastic retainer. This can be seen in the base’s large recess in the photo above. The retainer is removed by prying it with a screwdriver, and the ball is also removed.

I’m keeping all the little parts in a clean paper cup to prevent me from losing them as I go along.

There is also an over-pressure, safety relief valve, covered by a plastic cap. This assembly, including the cap, screw-out post, spring, metal-mushroom, and very small metal ball, is all removed and placed in the paper cup.

I can just hear ya hollering, “Crikey, Ned, what the heck have you gotten me into?”

It’s really not as bad as it all sounds and looks. If you keep track of all the little parts, and remember how they all go back together, this can be fun. Really! There’s learnin’ happenin’ here.

At this point, for my own education, I spent a bit of time envisioning how the jack works when it is being operated. The small jacking-piston and cylinder create high pressure using the principle of mechanical leverage. The pressurized oil is forced through the small hole in the bottom of that recess and up past the ball/hole/retainer in the large base recess.

All those balls in this device simply act as valves, sitting in nicely machined recesses, and only allowing oil to flow in one direction, pushing the ball slightly out of its recess. Oil pushing from the other direction forces the ball against the machined seal and shuts off the flow.

As it is needed, more oil is “sucked” into the small base recess from the main reservoir between the outer jack body and the inner cylinder.

The pressure in the cylinder jacks the piston up a small amount. The process is repeated as the piston gradually is lifted.

If too much pressure is generated inside the main cylinder, the oil can push the small ball and spring in the over-pressure relief valve and allow the excess oil to escape back into the main oil reservoir between the outer jack body and the inner cylinder. This acts as a safety to prevent the jack from being over-pressurized and dangerously rupturing.

And finally, when we want the jack to retract and go down, the pressure-relief valve is loosened. This allows oil to move past the ball at the bottom of that valve, and back into the main reservoir.

Since the only hole through which oil moves out of the main reservoir is the one leading to the bottom of the jacking-cylinder’s small recess, that is the hole that the small filter will be replaced into (so it functions to remove debris from the oil as it circulates). I find which hole that is by blowing into it to make sure the air is coming out of the ball-blocked hole in the bottom of the small base recess.

And, keeping debris out of the whole jack is why I’ve completely disassembled it. After the next drilling and tapping steps are completed, all the parts will be completely cleaned before any reassembly. Small bits of metallic debris are the enemy of a properly functioning jack. They can become lodged in the various ball-valve assemblies and allow slow leakage, preventing optimal performance.

Drilling and Tapping the Jack-Base to Receive the Pressure Gauge

You’ll notice, when looking at the jack base, that all the existing holes and inner “channels” that the oil flows through are located in the right side of the base.

Conveniently, this jack’s base has a nice flat area on its left side, and plenty of room on the left-inside of the large recess where a hole can be drilled.

This is the point we’ve been heading toward. I want to drill a 3/16-inch hole down from the bottom-inside of that main base recess, but not all the way through the base. I drill this hole about 3/8-Inch deep.

I want to drill in from the left-outside of the base with the same 3/16-inch drill bit, until that hole hits the first hole that was drilled. I only want to drill as far as that first hole so that I don’t hit any of the other inner channels in the base.

The hole coming in from the side is drilled high enough from the bottom to allow the fittings I’m going to install later to clear the press’s base plate. I also plan that hole so that it is centered in the bottom “thickness” of the base, so that the strength of the remaining metal surrounding my new fitting is maximized.

Drilling this hole, centered up 1/2 inch from the bottom of the base, accomplished all the above goals. And it kept the metal thickness between the hole and the bottom of the base no less than 5/16 inch, which is needed to withstand the internal jack pressures.

These two holes are gradually deepened until they hit each other, and no further.

The two holes will form a new channel which will allow the pressurized oil inside the inner jack cylinder to reach the new gauge which will read out the same pressure that exists inside the cylinder.

Warning: The main power tool I’m using in this process is a drill-press. Like Norm Abrams says, “Read and understand the safety precautions concerning this tool before you use it.” I do this drilling at low speeds. I firmly hold the piece I am drilling with a clamp and/or other tools. This drill-press can be my best friend, or it can slice my hands open and/or break bones. Be careful.

The hole in the side of the base is enlarged with a 5/16-inch drill bit (Q drill bit) enlarging a section about 3/4-inch deep. This side hole (only) then has threads cut in it with a 1/8-inch-pipe-thread tap.

This is also a good time to drill and tap the bolt holes, in the flanges on the base, which will attach the jack to the press’s bottom steel plate.

There, the hard part, the machining, is done. I now clean all the debris, excess paint, and metal shavings off of all the parts in a pot of clean kerosene or paint thinner. I pay special attention to the base to make sure all the small metal debris has been washed off of it and out of all its holes and channels.

After the parts have dried, the bottle jack is reassembled in the reverse order in which it was taken apart. Before adding the oil back into it, I attach the new pressure gauge using hydraulic fittings and Teflon tape. My local hydraulic-fitting supply-house was able to supply the fittings that I needed, and which would handle the pressure the jack will be exerting.

These fittings were inexpensive, and it pays to use fittings certified for hydraulic pressure, rather than plumbing fittings which might rupture under that pressure.

The gauge sells for about $22 at McMaster-Carr. It is a 2.5-inch diameter dial, glycerin filled, 0-10,000 psi range, 1/4-inch pipe-thread bottom-connected, Model #4053K16.

But, the same supply-house where I bought the fittings, had a very similar gauge for only $16. I bought one for a spare while I was there.

I have temporarily hooked up gauges to lower-pressure jacks with iron pipe fittings. But those plumbing fittings are not rated for the 8000 psi that will be developed in this new jack when it is putting out the full 6 tons of force.

Remember that when the gauge reads 8000 psi, that reading is multiplied by 1.5 to determine the force that the jack is exerting. That means an 8000 psi reading equals 12,000 pounds of force, the maximum force this jack is rated for. That’s why I chose a gauge with a range of 0-10,000 psi.

The Teflon tape is carefully wrapped on the pipe threads, in the direction that will tighten the tape wraps as the male threads are screwed into the female fittings. 4-5 wraps of the tape are put on each threaded section. I’m careful not to overlap the tape down onto the end of the fittings, where bits could break off and clog the channels or valves in the jack.

After the gauge was installed and all the fittings tightened up, I filtered the oil through a coffee filter and filled the jack back up with the oil through the fill hole on the back of the jack’s body. I pumped the jack up and down a few times to work any trapped air out of the system. Then the jack was installed on the rocket press.

I topped the oil off with more, new hydraulic-jack oil until it started to run out of the fill-hole in the main jack body. Then I installed the rubber plug.

I put my Pressure-to-Force gauge on the jack-plate, and jacked the press up to various pressures. This was to make sure that, indeed, the PtoF gauge read 1.5 times what the gauge on the bottle jack was reading. I also removed the PtoF gauge, and jacked the press up to its maximum pressure and let it sit there for a while to make sure it wasn’t losing any pressure through leaks or badly sealed steel-ball valves.

Everything worked great, so I moved the press into its permanent location on my work bench and attached it there with bolts which go through the two extra holes in the back of the bottom steel plate, and on through the workbench top.

Conclusion

Great! My fourth press is now up and running. Why the heck do I need four presses? I think I’ll paint and clean up my old Hobby Fireworks press and see if I can find a new pyro who wants to give it a good home.

There’s one final thing I thought about this press when it was done: “Hey, I built that thing. I know every part of it, and if anything goes wrong with it, I know how to fix it.”

I bought an extra bottle jack while I was working on the project, and drilled and tapped it at the same time as the main one. That way I have replacement parts, or the whole complete replacement jack if necessary.

This all results in a good feeling, and I suppose that’s why I do all of this in the first place.

Stay Green, and now on to more, ahh, Pressing matters.

Ned

How to Make a Hydraulic Rocket Press is a post from: Confessions of a Fireworks Man

If one does not have a ball mill there is another option for grinding coarse potassium nitrate into a free flowing, fine powder. Coffee and spice grinders work well for grinding small batches of individual chemicals.

Even though I have a ball mill, there are times when the coffee grinders come in handy for pulverizing smaller batches of chemicals. I have some Parlon, most of which will pass through a 40-mesh screen, but which has some larger particles as well. I’ll take those larger bits and run them through the coffee grinder in order to reduce them to smaller particles.

Warning: Dedicate one grinder for use on oxidizers, and another one for use on fuels such as charcoal. We don’t want fires or explosions when we’re grinding chemicals. Never grind complete or mixed compositions such as black powder in a coffee grinder.

I have found two kinds of coffee grinders: blade-grinders and burr-mills. Don’t get a burr-mill; they don’t work as well as blade-grinders. The blade-grinders have a stainless steel blender type blade that spins at high speeds in the bottom of the material cup, chopping the material into small bits in the process.

I have purchased many of the smaller, less expensive, blade-type coffee grinders. But here’s the warning: they really don’t last too long if you mill chemicals for a minute or two at a time. To use them, mill your chemicals in pulses of a few seconds at a time. I’ve found that shaking them while pulse-grinding gives me the fastest results.

The Kitchenaid blade mill has a larger hopper, and a larger, more powerful motor, and is rated to be used often. I’m hoping that it will last longer than the $13 WalMart models I’ve been using.

I put a half-cup, 4.6 ounces, of 12-mesh potassium nitrate into its hopper, pressed down on its lid to start it, and pulse-milled the powder for just under a minute, shaking the grinder now and then in the process.

Quite a bit of fine powder started to accumulate on the inside top of the clear lid as it milled. I dumped the ground chemical onto my 100-mesh screen, and used a fine paint brush to clean off any that was clinging to the inside of the hopper or the lid.

About three-fourths of this milled powder would pass through the 100 mesh screen, and I set aside that which wouldn’t to be ground again with the next batch.

Granular potassium nitrate can be dried if necessary, and ground easily with a ball mill or with a coffee blade mill, so that it passes through a 100-mesh screen and is ready to be used in pyrotechnic compositions.

Using a Coffee/Spice Grinder to Pulverize Potassium Nitrate is a post from: Confessions of a Fireworks Man