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InfernoMDM
January 15th, 2007, 03:54 AM
I poked around and poked around the forum and can't find anything about how to make Ballistics Gelatin. I was kind of amazed, because all the projectile weapons created here, I figured you guys would want to test it in a good semi scientific medium. Although I use to indulge in the wet newspaper trick I moved up to homemade Ballistics Gel for a few interesting rounds I picked up. I thought some of you might like the info.

The recipe I used.
http://www.customcartridge.com/pdfs/BallisticGel.pdf

Calibration and info for the scientist.
http://www.firearmstactical.com/tacticalbriefs/volume4/number1/article412.htm

Before I post someone elses info I wanted to pass on a few pointers.

1. Make sure your weapon is centered with the gel. My friend set it up just askew and the round passed out the side. It was a big waste.

2. Make sure your container doesn't flex to much, or you will mess up the gel during transport.

3. Stir by hand with friends. If you use a drill your gel may be impossible to see into further then a inch or so.

3. Ballistic Gelatin Recipe
by Ed Harris @1:109/120.3006 via 1:2410/271 FIDOnet

The target material is prepared from gelatin, USP. The government laboratories purchase this as Pharmagel A, Type 250 from the Kind & Knox Co., Park 80 West, Plaza 2, Saddle Brook, NJ 07662. The last time I bought any was in 1984, and at that time the price was $2.40/lb., or about $600 for a 55 gal. drum, shipped F.O.B. from Sioux City, IA.

The powder is mixed 10 percent by weight in warm, but not boiling water until dissolved, and then poured into moulds and chilled in a large refrigerator. The standard block size is 15x15x30cm for handgun bullets and 20x20x50cm for rifle bullets, but improvised moulds such as from cal. .50 M2A1 ammunition cans work well.

You will also need Thymol or cinnamon oil as a clarifier, which is added in the proportion of 1 drop per liter. You will also need heavy duty electric stirrers or an industrial mixer, moulds, a release agent, such as Pam cooking spray for releasing the castings, LD plastic film or Saran wrap for wrapping the blocks, a freezer for storage if you will not use the blocks within a week, and foam coolers to transport them to the range, if you do not have a walk-in cooler near your lab.

To do this right, establish the tare weight of a 5 gallon stainless steel container in which you will heat the water and mix the gelatin. Ideally this should have a spigot on the bottom to aid decanting the dissolved gelatin into the moulds. Add 12 liters of water to the container and bring the temperature to 65 degs. C and adjust the weight by adding or deleting water to obtain 12,000 grams. Place two electric stirrers into the hot water, one near the top and the other near the bottom of the container. Add three grams of Thymol or 12 drops of cinnamon oil and stir until dissolved in the hot water. Add 1500 grams of Pharmagel A to the hot water, breaking up any lumps with a stainless steel rod or paddle, to supplement the stirrers, as necessary.

After the gelatin is dissolved, in 10-15 minutes, turn off the stirrers and remove them from the solution. Allow the bubbles and foam to rise to the surface for 20 minutes. If the container used does not have a spigot at the bottom, it is necessary to skim the foam off the surface before transferring the solution to the moulds. Allow the warm gelatin to stand at room temperature for at least one hour after transferring, so additional foam which rises to the top may be removed.

Place the gelatin in a refrigerator overnight at 0-5 degs. C. The gelatin may then be removed from the moulds by placing the container in hot water. After 15-20 seconds use a spatula to loosen the gelatin from the sides of the container. After two minutes remove the mould from the hot water and invert it over a piece of plastic film spread on a flat surface.

Once the gelatin is removed from the mould it should be allowed to remain at room temperature for one hour, then tightly sealed in plastic film and the wrapped block inserted into a plastic bag, which is again sealed to prevent evaporation, which drastically changes the consistency of the gelatin. Once tightly wrapped, the blocks can be stored up to six months in a freezer, or up to one week in a refrigerator. Unused blocks should be frozen immediately to retard mold growth. Before firing the blocks must be allowed to thaw and stabilized overnight at a temperature of 5-10 degs. C, because proper consistency is a function of the tempoerature.

Evaluation of the blocks is best accomplished by flash X-ray photography which permits measurement of transient cavity volume as a function of projectile striking velocity, time, distance penetrated and projectile exit velocity energy deposit). If high speed photographic equipment is not available, it is useful to use a small caliber calibration test shot, such as a steel .177 air rifle shot from a Daisy pump-up air rifle known to give consistent performance, which can be placed as a consistency calibration check in a corner of the block out of the way. The permanent cavity can then be made to stand out well for still photography by injecting a colored water solution of ten drops food dye to a liter of water, using as veterinary syringe or laboratory wash bottle to reach all corners of the permanent cavity. To provide proper scale for the photograph, a piece of graph paper can be photocopied onto overhead transparency film, and used as a template to be positioned over the shot. The block should then be placed on a light table or photographed using diffused, backlit strobe flash. Detailed ammunition test methodology is available in various open-source medical and technical references.

In Home Mix We Trust, Regards, Ed

stupid939
January 15th, 2007, 12:48 PM
I was actually looking into this the other day. I think it was cause of Mythbusters or something, but I found a lot of the same information. I kind of ignored the Knox Gelatin idea because it seemed to me that it would be too weak and tear easily.

How well did it hold together? What color is it (clear-white)? I didn't find any of these answers and so I never made it. Do you mind answering them since you already made it?

InfernoMDM
January 15th, 2007, 02:18 PM
We have made 4 sets. IT comes out in this yellow color, one of the links suggests painting something white when you are going to take photos. You place the white background behind it and take the shot. I also would suggest foam core board as its white and very light.

Yes it is fragile so it takes two people to work it, but its not as fragile as say jello. You have to keep it damned cold though, it makes it easier, and safer to move.

It will get almost white if you stir with a anything powered. We used pieces of wood siding(flat wide is best) the second time and it came out so much better. Just have 2-3 friends and do the stirring for 20-25 minutes. The second batch was clear and a lot firmer.

stupid939
January 16th, 2007, 01:33 PM
Since there's not much else going on on this forum, I'll ask some more questions.

What kind of projectiles did you fire at it: bullets, crossbow bolts, homemade weapons?

Compared to the human body, is it about the same density, stiffness, flexibility?

I can't think of any more right now, but that should be a good start.

InfernoMDM
January 16th, 2007, 01:59 PM
Bullets only. I had picked up some wild 357 SIG rounds that I believe went 2200 FPS. They promised that they would get 9" depth, and explode which technically they did, however most of the particles didn't go that far. I know people have used as ballistics gel for several different projectile tests, to include homemade items.

Ballistics gel is "about" the same consistency as human muscle. Remember humans have internal organs, bones etc. The scientists that work with this stuff have set depths to represent impact with things such as leather or denim, bone etc. I think the exact details are either in the link I posted, or I will get them for you if I can find them.

However we do know that 12-14 inches is the average depth a hollow point round from a pistol penetrates. From there we can guesstimate some things. I will try to get better info. Also I think the minimum penetration depth required is 7-8 inches assuming no clothes and bones get in the way.

Apparently my search fu is weak as there is a archived thing about ballistic gel. However the link is dead so I don't feel to bad.

nbk2000
January 16th, 2007, 09:50 PM
Gelatin has it's problems, such as storage and preparation being a hassle.

A new ballistic simulant "transparent gel candle" (experimental study).

General Surgery Department, Gulhane Military Medical Academy, Ankara-Turkey. mdakak@gata.edu.tr

BACKGROUND: Inanimate tissue stimulants have been used to show the bullet effects in ballistic studies. Gelatin has been being used as a ballistic stimulant for the last 20 years. It was considered that transparent gel candle (kraton in white paraffin oil) might be used as a soft tissue stimulant that can be an alternative for gelatin. METHODS: For calibration of transplant gel candle, firstly it was shot at the 10% ordinance gelatin at 4 o C, and several concentrations of the transparent gel candle at 4 o C, by later on, by using a competition air gun. It was seen that 15% kraton in 85% white paraffin oil is the most suitable concentration. This kind of transparent gel candle blocks tested by using 9 mm parabellum and 7.62 mm x 51 (NATO 7.62) infantry rifle bullets and high-speed camera. RESULTS: Because of its transparency and elasticity, the penetration, permanent and temporary cavities of bullets were observed clearly in transparent gel candle. CONCLUSIONS: As a result, transparent gel candle is a good soft tissue stimulant that it can be used in wound ballistic studies.

Perma-Gel simulant (http://www.cabelas.com/cabelas/en/templates/links/link.jsp?id=0037512216133a&type=product&cmCat=search&returnPage=search-results1.jsp&QueryText=gelatin&N=4887&Ntk=Products&Ntx=mode+matchall&Nty=1&Ntt=gelatin&noImage=0) seems a likely to be the above material.

Skin is also an important part of the penetration model, since you don't see many people running around without their skin on. ;)

The target values of the mechanical properties of the skin simulant were the following: threshold velocity v[th] = 94 ± 4 m/s, tensile strength 18 ± 2 N/ mm[2] and elongation at break 65 ± 5%. A selection of synthetic and natural materials was evaluated as skin simulants by analysing their mechanical and ballistic properties. The results were compared to literature values obtained with human cadavers. The tests showed that the best skin simulant of the ones evaluated was semi-finished chrome tanned upholstery crust cowhide of 0.9-1.1 mm nominal thickness. Its threshold velocity was 90.7 m/s, tensile strength 20.89 ± 4.11 MPa and elongation at break 61 ± 9%. These values are the same as the average values of human skin. Of the synthetic materials evaluated, 1 mm thick natural rubber can be used on impact side as a threshold velocity filter with some reservations although its theoretical threshold velocity is only 82.9 m/s.

cracker
January 17th, 2007, 10:29 PM
Kraton 1650 & 1652 Polymers are recommended for the White Pariffin Oil suggested.

Due to the high density of the 1650, machinery is needed for proper mixing, for this reason Kraton 1652 is used for "homemade" gels.

One of the distributers for Krayton Polymers is Chemcentral out of Seattle WA.

InfernoMDM
January 26th, 2007, 04:23 PM
Perma-Gel simulant (http://www.cabelas.com/cabelas/en/templates/links/link.jsp?id=0037512216133a&type=product&cmCat=search&returnPage=search-results1.jsp&QueryText=gelatin&N=4887&Ntk=Products&Ntx=mode+matchall&Nty=1&Ntt=gelatin&noImage=0) seems a likely to be the above material.

Interesting stuff. I think people don't use it because of its inability to be calibrated after the first shot, and its expense compared to the stuff they make. I'll see if anyone can check on up on this.

cracker
March 25th, 2007, 01:00 PM
Throughly mixing Kraton Polymer 1652 with White Paraffin Oil will "cure" the Oil to a "rubbery state". Achieving the desired Ballistics Gel with the proper Mold.

nbk2000
March 25th, 2007, 07:31 PM
The idea behind Ballistic Gelatin, was to have a material that best simulated human tissue.

While anything can be shot, that doesn't make it suitable to the task, even if it is a gel.