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Regarding penetrators. Is
there any rule or guideline to determine the amount of distance between
conductors in a penetrator with regard to voltage and current. For
example, you could hardly have 1/16” (1.6mm) separation for 10,000
volts) and I have heard that some penetrators have failed with using ballasted
lights when initializing the arc. Also another consideration is that
brass appears to be used instead of copper mostly and the current density of
brass will be substantially less than for copper. I vaguely remember
some figure like 2000 amps per square inch for copper. If the cross
section area is too low for higher currents in some motor application the
temperature could adversely affect the resin used. I have not seen
much on penetrator design but I think it is an issue which would gratefully
receive some knowledge and guidelines from the more learned members of
p-subs. ABS and G/L have criteria for testing penetrators and what megger
tests can be used and how much helium can be passed for leakage. I am
slowly compiling all your gems of wisdom into a mini Wikipedia for subbers.
So far I don’t have the penetrators section very well documented.
Up to 29 pages so far and happy to send it to someone if interested. There
is however an interesting catalogue available which classes penetrators into 3
different voltage services and shows commercially available penetrators and
plugs. Hugh From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Emile van
Essen Thanks for the info’s!! It is indeed small; about 1
“ diametric. http://picasaweb.google.nl/submachine55/Kreideseesub#5278628917830184690
and http://picasaweb.google.nl/submachine55/Kreideseesub#5333919163143993442
I made already grooves to
have better adhesion. But I consider fine sandblasting. Frank, Please send the drawing. Regards, Emile Van:
owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org]
Namens Cliff Redus Emile For small volumes of epoxy like for an
electrical penetrator, just about any two part epoxy system will work as long
as the surface roughness is adequate. The problem comes when you want to
cast larger volumes. For large volumes, you have two issues of
concern. The first is getting the epoxy, which can have a high a viscosity,
to flow into all the cavities. The second issue has to do with the
exothermic reaction. For large volumes if the reaction rate is fast, the
temperature gets very hot and the part can crack. I was concerned with
both these issues when I cast the two part epoxy that formed the binding agent
for the syntactic foam for my boat. My casting had 270 lbs (123 kg) of
catalyzed resin which I cast in one piece. To address these issues, I
contacted a company that manufactured epoxy resins and catalyst. Their
guidance was to go with an epoxy resin/ catalysis system that had a low
viscosity so that it could be easily poured and second go with a catalyst that
generated a slow, low exothermic reaction. The resin I used was Huntsman
Araldite GY-9667 with the associated catalyst Huntsman Jeffamine D-230
Polyoxypropylenediamine. These were mixed on a weight bases of 100% resin
(Part A) to 29.46 % catalyst (part B). The canalized resin had a
viscosity of 375 cp at 77 F (part A 500 cp and part B 9 cp at 77 F. The curse
time was several days. This system worked fine. Not sure if you can
get this epoxy system in Europe but you may be able to find something similiar. From: Emile van
Essen <emile@airesearch.nl> Hi, I am about to cast epoxy in some self made
el. Penetrators and a barrier in a thruster First idea is to use normal aero modelling
epoxy but when not okay I have a real problem to get it out the thruster. Does someone have the knowledge or experience
about kind of epoxy, adhesion to metals viscosity etc?? Thanks in advance! Emile van Essen Alkmaar, the Netherlands No virus
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