Sciencemadness Discussion Board - Melt cast(Petn/etn 70:30)

Melt cast(Petn/etn 70:30)

Petn1933 - 25-10-2019 at 21:44

Mass:30gr
density:1.56
Ratio:70/30(petn/etn)
Iron Plate Thickness:9mm(I dont remember exactly)

FDE13266-596E-4C90-BBE1-14A87A288F2A.jpeg - 2.3MB

[Edited on 26-10-2019 by Petn1933]

5641029C-C33E-4978-9B43-142D024194C6.jpeg - 2.8MB

[Edited on 26-10-2019 by Petn1933]

BFE25B2C-0D0A-4650-BB64-AE1E9238DB5B.jpeg - 3MB

[Edited on 26-10-2019 by Petn1933]

07880BE5-D88A-46DD-8308-95CC486FC205.jpeg - 2.6MB

[Edited on 26-10-2019 by Petn1933]

G-Coupled - 26-10-2019 at 03:42

Wow - that looks quite energetic indeed.

twelti - 26-10-2019 at 09:34

What did you use for det?

Petn1933 - 26-10-2019 at 11:54

Electric detonator(150mg sads,700mg petn)
1g petn as booster for reliable detnation!

G-Coupled - 26-10-2019 at 12:36

Less than a GRAM of EM? I'm guessing the charge wasn't shaped at all?

twelti - 26-10-2019 at 20:28

Quote: Originally posted by G-Coupled

Less than a GRAM of EM? I'm guessing the charge wasn't shaped at all?

I'm reading 30 gr for the main charge.

Petn1933 - 26-10-2019 at 22:50

main charge was 30g (21g petn ;9g etn)
on the top of that put 1g petn(as booster) , then electric detonator initiated booster and main charge.

yobbo II - 30-10-2019 at 09:13

Is it safe to melt ETN?
See life after detonation thread

Stay safe,
Yob

MineMan - 30-10-2019 at 22:36

Those that do it think it is. But yah... it gets pretty sensitive... DAUN is a much better choice.

Herr Haber - 31-10-2019 at 01:07

You dont need to be around molten ETN to melt it.
Nobody said you should melt it and pour it, swirl it or whatever.

If I had been in OP's shoes I would have mixed my ETN + PETN, put it in a mold and THEN put the mold in boiling water.
Come back 15mn later, remove mold from water, let it cool.
ETN was obviously used a a binder.

Petn1933 - 31-10-2019 at 01:33

Quote: Originally posted by yobbo II

Is it safe to melt ETN?
See life after detonation thread

Stay safe,
Yob

yes, in small quantities we able to melt it with indirect heat and hot water
though ETN Three times more sensitive than Petn!!

Petn1933 - 31-10-2019 at 01:57

Quote: Originally posted by MineMan

Those that do it think it is. But yah... it gets pretty sensitive... DAUN is a much better choice.

As you know, working with explosives requires a lot of attention. Because the first mistake is the last mistake.
The etn sensitivity in the molten state is equal to nitroglycerin. But if it is well neutralized and temperature controlled, it can be melted in a small amount.

DennyDevHE77 - 15-8-2023 at 23:05

Please tell me, did you process PETN in any way (recrystallization, grinding), after synthesis? Did you stir the melt during fabrication or did you just mix ETH/PETN and immerse it in a hot water bath? It seems to me that the melt density of this mixture should be above 1.56 g/cm³. Considering that cast ETH at different cooling methods gives from 1.65 to 1.7 g/cm³. And density of monocrystalline PETN = 1.77 g/cm³.

Could it be due to the small needle-like crystals of PETN creating small voids? Or lack of ETN, which failed to fully immerse PETN crystals in the melt? It seems like the optimal ratios are 65/35.

P.S. True I'm not quite sure how much more powerful the mixture would be at a density of 1.7 g/cm³. Pure pressed PETN at a density of 1.51 g/cm³ already produces a detonation velocity of 7520 m/s. And at 1.7 g/cm³ it is 8110 m/s. So the difference is essentially only ~500 m/s. With ETH (as well as with ETH/PETN), I'm sure it's the same.

[Edited on 17-8-2023 by DennyDevHE77]

OneEyedPyro - 16-8-2023 at 10:04

Quote: Originally posted by DennyDevHE77

Please tell me, did you process PETN in any way (recrystallization, grinding), after synthesis? Did you stir the melt during fabrication or did you just mix ETH/PETN and immerse it in a hot water bath? It seems to me that the melt density of this mixture should be above 1.56 g/cm³. Considering that cast ETH at different cooling methods gives from 1.65 to 1.7 g/cm³. And density of monocrystalline PETN = 1.77 g/cm³.

Could it be due to the small needle-like crystals of PETN creating small voids? Or lack of ETN, which failed to fully immerse PETN crystals in the melt? It seems like the optimal ratios are 65/35.

P.S. True I'm not quite sure how much more powerful the mixture would be at a density of 1.7 g/cm³. Pure pressed PETN at a density of 1.51 g/cm³ already produces a detonation velocity of 7520 m/s. And at 1.7 g/cm³ it is 8110 m/s. So the difference is essentially only 500 m/s. With ETH (as well as with ETH/PETN), I'm sure it's the same.

[Edited on 16-8-2023 by DennyDevHE77]

At some point PETN seems to stop dissolving. I can say that a 50/50 mix appears fully liquified and homogeneous. I assume it would be a hassle to exclude air from the cast entirely once PETN begins to remain solid, at that point you're probably going to start seeing lower densities.

While 500 m/s doesn't sound all that significant you also have to factor in the greater energy density. You're getting 12% more gas generation by volume and 8% higher VoD, due to the higher temperature of the detonation products with the higher density and VoD you will see a significant increase in brisance.
An increase from 1.5 g/cc to 1.7 g/cc is a much bigger difference in performance than you might assume.

DennyDevHE77 - 17-8-2023 at 02:17

And if you get a vacuum cap, is it worth it? Or is it easier to make a 50:50 mixture where the ETH is guaranteed to fill all the cavities between the PETN crystals?

Just wondering if PETN could crystallize into large crystals, not the long needles it usually falls out in when pouring acetone solution into water? I think there is also such a thing in the industry as ultrasonic pouring, but I'm not sure how safe it is with ETH.

OneEyedPyro - 18-8-2023 at 05:47

Quote: Originally posted by DennyDevHE77

And if you get a vacuum cap, is it worth it? Or is it easier to make a 50:50 mixture where the ETH is guaranteed to fill all the cavities between the PETN crystals?

Just wondering if PETN could crystallize into large crystals, not the long needles it usually falls out in when pouring acetone solution into water? I think there is also such a thing in the industry as ultrasonic pouring, but I'm not sure how safe it is with ETH.

ETN and PETN form a eutectic mixture. At a 50/50 ratio they go into solution together and harden at the same temperature but after certain point the PETN doesn't seem to dissolve and floats on top.
Maybe with some stirring or higher temps it would dissolve but I REALLY wouldn't recommend trying that.
At a 50/50 ratio it's still absurdly powerful and I don't think a higher percentage of PETN would add enough power to be worth the trouble of dangerously handling it.

[Edited on 18-8-2023 by OneEyedPyro]

DennyDevHE77 - 19-8-2023 at 01:06

Thanks, I didn't realize 50/50 was a eutectic mixture. In fact, I thought that 65/35 was considered the optimal blend because it forms a uniform blend where all the PETN crystals are evenly covered by the ETH melt.

However, I wanted to know about the 65/35 composition mainly because of the benefits. PETN is much cheaper than ETH.

OneEyedPyro - 19-8-2023 at 08:16

Quote: Originally posted by DennyDevHE77

Thanks, I didn't realize 50/50 was a eutectic mixture. In fact, I thought that 65/35 was considered the optimal blend because it forms a uniform blend where all the PETN crystals are evenly covered by the ETH melt.

However, I wanted to know about the 65/35 composition mainly because of the benefits. PETN is much cheaper than ETH.

It's possible that 65/35 is the limit that PETN will go into solution. I tried 75/25 at 70C for 20 minutes and found that the PETN didn't fully dissolve, a lot was still on top and stuck to the sides of the container.