twelti
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Epoxy in Caps
I have been using epoxy in constructing my caps. There is a possibility that the epoxy may come in contact with the primary and or secondary charge.
Has anyone ever heard of any issues with incompatibilities between 2 part epoxy and any EM's?
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MineMan
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Epoxy is great! Epoxy putty even better! Epoxy can heat up, but the best thing to do is to do a test run! Hot glue is even better, especially if you
can find a tip like that of a needle.
Best of luck 
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XeonTheMGPony
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use a small wad of compressed tissue paper as a gasket/isolater.
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twelti
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Excellent ideas, thank you.
@MM, I also love that putty. I always keep a couple of tubes around.
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XeonTheMGPony
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I use a basic 2 part epoxy mixed with sand for filler, then used a couple basic printer paper gaskets to prevent it fouling the primer.
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twelti
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Quote: Originally posted by XeonTheMGPony  | | I use a basic 2 part epoxy mixed with sand for filler, then used a couple basic printer paper gaskets to prevent it fouling the primer.
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Do you mean you are winding a strip of paper around the inner tube to widen it and make a gasket? That is sort of what I have been doing, just using
thin strip of masking tape.
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twelti
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Found this in "High Energy Materials: Propellants, Explosives and Pyrotechnics", Agrawal:
Epoxy resins: The compatibility of epoxy resins with explosives and propellants is largely decided by the curing agent or hardener. Some curing
agents promote cure by catalytic action whereas some participate directly in the reaction and become a part of three - dimensional networks.
– As a rule of thumb, epoxies cured with aliphatic amines, cause a majority
of explosives and propellants to be excessively reactive. Epoxies cured
with polyamides (of low molecular weight such as versamide) also cause
some explosives to be excessively reactive.
– On the other hand, epoxies cured with acid anhydrides and phenolic
resins exhibit little or no reactivity when stored in direct contact with
explosives and propellants.
Hmmm. I need to look further into this!
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wessonsmith
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| Quote: Originally posted by twelti | Found this in "High Energy Materials: Propellants, Explosives and Pyrotechnics", Agrawal:
Epoxy resins: The compatibility of epoxy resins with explosives and propellants is largely decided by the curing agent or hardener. Some curing
agents promote cure by catalytic action whereas some participate directly in the reaction and become a part of three - dimensional networks.
– As a rule of thumb, epoxies cured with aliphatic amines, cause a majority
of explosives and propellants to be excessively reactive. Epoxies cured
with polyamides (of low molecular weight such as versamide) also cause
some explosives to be excessively reactive.
– On the other hand, epoxies cured with acid anhydrides and phenolic
resins exhibit little or no reactivity when stored in direct contact with
explosives and propellants.
Hmmm. I need to look further into this! |
This is what I use on my melt-cast ETN and NHN. I have detonators that are 2 years old and still going strong.
https://www.amazon.com/gp/product/B0006945SS/ref=ppx_yo_dt_b...
Here is the MSDS
https://www.rectorseal.com/web-media/SDS_Rectorseal-EP-200-A...
curing agent is 2,4,6-Tris(dimethylaminomethyl)phenol, DMP-30
[Edited on 29-7-2019 by wessonsmith]
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twelti
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| Quote: Originally posted by wessonsmith | | Quote: Originally posted by twelti | Found this in "High Energy Materials: Propellants, Explosives and Pyrotechnics", Agrawal:
Epoxy resins: The compatibility of epoxy resins with explosives and propellants is largely decided by the curing agent or hardener. Some curing
agents promote cure by catalytic action whereas some participate directly in the reaction and become a part of three - dimensional networks.
– As a rule of thumb, epoxies cured with aliphatic amines, cause a majority
of explosives and propellants to be excessively reactive. Epoxies cured
with polyamides (of low molecular weight such as versamide) also cause
some explosives to be excessively reactive.
– On the other hand, epoxies cured with acid anhydrides and phenolic
resins exhibit little or no reactivity when stored in direct contact with
explosives and propellants.
Hmmm. I need to look further into this! |
This is what I use on my melt-cast ETN and NHN. I have detonators that are 2 years old and still going strong.
https://www.amazon.com/gp/product/B0006945SS/ref=ppx_yo_dt_b...
Here is the MSDS
https://www.rectorseal.com/web-media/SDS_Rectorseal-EP-200-A...
curing agent is 2,4,6-Tris(dimethylaminomethyl)phenol, DMP-30
[Edited on 29-7-2019 by wessonsmith] |
Hmmm. is 2,4,6-Tris(dimethylaminomethyl)phenol an aliphatic amine or a phenol (or both)?
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XeonTheMGPony
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I just used generic 2 part, I have had caps well over 10+ years fire like fresh, critical thing is you must control ambient conditions and ensure
every thing is as dry as possible.
Metal tube, load, then place your electrical match system and load epoxy, when the epoxy is semi cured crimp it
| Quote: Originally posted by twelti | | Quote: Originally posted by XeonTheMGPony | | I use a basic 2 part epoxy mixed with sand for filler, then used a couple basic printer paper gaskets to prevent it fouling the primer.
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Do you mean you are winding a strip of paper around the inner tube to widen it and make a gasket? That is sort of what I have been doing, just using
thin strip of masking tape. |
more like punched disks that are a fraction of a fraction larger then the tube, it is called an interference fit
https://en.wikipedia.org/wiki/Interference_fit
I have had mine fire with no issue in up to 30 feet under water, fresh and salt
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twelti
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| Quote: Originally posted by XeonTheMGPony | I just used generic 2 part, I have had caps well over 10+ years fire like fresh, critical thing is you must control ambient conditions and ensure
every thing is as dry as possible.
Metal tube, load, then place your electrical match system and load epoxy, when the epoxy is semi cured crimp it
| Quote: Originally posted by twelti | | Quote: Originally posted by XeonTheMGPony | | I use a basic 2 part epoxy mixed with sand for filler, then used a couple basic printer paper gaskets to prevent it fouling the primer.
|
Do you mean you are winding a strip of paper around the inner tube to widen it and make a gasket? That is sort of what I have been doing, just using
thin strip of masking tape. |
more like punched disks that are a fraction of a fraction larger then the tube, it is called an interference fit
https://en.wikipedia.org/wiki/Interference_fit
I have had mine fire with no issue in up to 30 feet under water, fresh and salt |
So you are using standardized tube sizes so you can find these to fit, or are you punching your own?
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XeonTheMGPony
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| Quote: Originally posted by twelti | | Quote: Originally posted by XeonTheMGPony | I just used generic 2 part, I have had caps well over 10+ years fire like fresh, critical thing is you must control ambient conditions and ensure
every thing is as dry as possible.
Metal tube, load, then place your electrical match system and load epoxy, when the epoxy is semi cured crimp it
| Quote: Originally posted by twelti | | Quote: Originally posted by XeonTheMGPony | | I use a basic 2 part epoxy mixed with sand for filler, then used a couple basic printer paper gaskets to prevent it fouling the primer.
|
Do you mean you are winding a strip of paper around the inner tube to widen it and make a gasket? That is sort of what I have been doing, just using
thin strip of masking tape. |
more like punched disks that are a fraction of a fraction larger then the tube, it is called an interference fit
https://en.wikipedia.org/wiki/Interference_fit
I have had mine fire with no issue in up to 30 feet under water, fresh and salt |
So you are using standardized tube sizes so you can find these to fit, or are you punching your own? |
both
I use a standard tube size so I can use a standard punch, cereal box card board is the best for disks
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