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| Bob... |
 Posted: Thu Oct 15, 2009 12:29 pm |
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On Oct 15, 7:39 am, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:
Quote: Bob <robg... at (no spam) bestweb.net> fired this volley in news:90346ee8-62fc-41d4-
a08a-1a93fc88c... at (no spam) z34g2000vbl.googlegroups.com:
The effect produces a rim like that of a
tin can. I've been filling it in with sawdust & glue before pasting
over, but it seems one could deliberately produce a rim and trowel
onto it some dampened tailed compo, which could be built up into a
tall enough layer to have enough burn time.
You've described an arrangement similar to the plastic RAP bombette
construction. The cavity so made is about 10-12mm deep on those casings.
It's not an artifact of assembly - as it is in your case - but purpose-
made to hold the rising effect/timing element.
I thought RAP shells were round. I forgot what "RAP" stands for,
except that the P is for "plastic".
I do a smaller version of the description above for 5/8" mini-shells.
Harry sells paper end plugs for 0.5" ID. They fit best if the case is
rolled with that end (or both ends) tapered. I poke a hole in the
middle, insert visco, hot glue or PVA around the inside of the hole,
PVA glue the plug to the cylinder, then fill the concavity with dough-
wet star comp, fuse sticking thru the middle. If need be, the surface
can be dipped onto dry priming compo or FFFg BP, but as long as the
time fuse lights it's going to ignite the rising effect. Then the
break & stars, or sawdust & salute mix, can be loaded and the other
end plugged with either a similar (but minus the rising effect) paper
plug, or sawdust & glue. Some time I should try a color comp on one
end and a tail effect on the other.
The depth of these paper plugs is considerable in relation to their
width, so there is no need to build up the star comp beyond the rim of
the case. It's as easy to seal the visco time fuse hole this way with
star comp as it would be with NC lacquer or glue, and priming either
the compo or the fuse suffices for ignition. The fuse burns faster
than the comet so formed, so at break the burning star is ejected or
fragmented, giving a mini-crossette effect. I used to wrap the visco
with foil but decided that was overkill for such small items.
Robert |
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| Lloyd E. Sponenburgh... |
| Posted: Thu Oct 15, 2009 5:55 pm |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:ea6972ec-7033-4b14-
9871-a56558a27824 at (no spam) j9g2000vbp.googlegroups.com:
Quote: I thought RAP shells were round. I forgot what "RAP" stands for,
except that the P is for "plastic".
R(apid) A(ssembly) P(lastic) shells.
The rest of what you described is just as some Chinese small cake effects
are built.
LLoyd |
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| Bob... |
| Posted: Thu Oct 15, 2009 7:03 pm |
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Quote: The rest of what you described is just as some Chinese small cake effects
are built.
LLoyd
Mine are for cakes too, but I've never seen in the debris from
commercial cakes end plugs that look like the ones from Harry, or like
they were ever in that condition. All I've seen on the ground with a
hole in the middle are flat discs that look pretty rigid. Harry's are
sort of like bottle caps, but smoother than what you would get by
malleting a disc into a smaller hole to form it, i.e. no "crimps".
Kyle Kepley's (I think it was his) "Passfire" article used a miniature
aerolite technique, with a pressed clay bulkhead and a poked (or maybe
drilled) passfire hole with match along the inside of a wall.
Robert |
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| mikes2653... |
| Posted: Fri Oct 16, 2009 10:58 am |
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On Oct 14, 9:36 pm, Bob <robg... at (no spam) bestweb.net> wrote:
Quote: Well duh, that's my very problem. It seems only thinner string would
be "sharp" enough to dig into that curved a surface when I do it
without a horse.
How can you apply proper tension without a horse? Also, how do you
paste your string? Of course the string will slip if used dry. |
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| Bob... |
| Posted: Fri Oct 16, 2009 1:47 pm |
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On Oct 16, 4:58 pm, mikes2653 <ekim2... at (no spam) gmail.com> wrote:
Quote: How can you apply proper tension without a horse?
With my hands. I've thought about stepping on the loose end, but
didn't want to get the floor dirty. Once I tied the end down and
walked toward it, but I couldn't tell the difference in the dried
product from when I just paid it out from my fist.
Quote: Also, how do you paste your string?
By soaking it in the bowl after wetting it with water. Same as I make
match, come to think of it, except with no application of dry material
after removal from the slurry. Different materials applied, of
course.
Quote: Of course the string will slip if used dry.
Feels pretty slippery with paste! But it's not much of a problem with
3" shells because their radius of curvature is enough.
Robert |
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| Lloyd E. Sponenburgh... |
| Posted: Fri Oct 16, 2009 6:14 pm |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:bb8fb43f-b882-42d7-
8091-ae4fbc70fdd7 at (no spam) j19g2000yqk.googlegroups.com:
Quote: Feels pretty slippery with paste! But it's not much of a problem with
3" shells because their radius of curvature is enough.
It's not the least slippery if it's drawn tight enough to "bite", but that
can't reasonably be done if you don't have a horse, and it cannot be done
with cheap cotton kitchen twine; you must have a strong twine such as
linen (or a large gauge, long-staple cotton twine).
LLoyd |
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| Lloyd E. Sponenburgh... |
| Posted: Fri Oct 16, 2009 6:15 pm |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:bb8fb43f-b882-42d7-
8091-ae4fbc70fdd7 at (no spam) j19g2000yqk.googlegroups.com:
Quote: Feels pretty slippery with paste! But it's not much of a problem with
3" shells because their radius of curvature is enough.
Oh... and I forgot to say: You should only soak the twine in paste, not
in water first, or it will not well absorb the paste.
LLoyd |
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| Bob... |
| Posted: Sat Oct 17, 2009 5:17 am |
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Quote: Bob <robg... at (no spam) bestweb.net> fired this volley in news:bb8fb43f-b882-42d7-
8091-ae4fbc70f... at (no spam) j19g2000yqk.googlegroups.com:
Feels pretty slippery with paste! But it's not much of a problem with
3" shells because their radius of curvature is enough.
Oh... and I forgot to say: You should only soak the twine in paste, not
in water first, or it will not well absorb the paste.
LLoyd
It's supposed to ABSORB the paste? Like the paper does? I hadn't
realized that, thanks. The twine does seem to stiffen when it dries,
but I'd never realized that was an intended effect. I thought the
paste was to LUBRICATE the twine for pulling it over the edge of the
cylinder. Where it bites into the edges, it can develop considerable
friction.
I started with cotton string, but then got some rough twine. With 3"
shells it seems to get tight enough with my just paying it out from my
hand and pulling each half loop, although sometimes it slips and I
have to go back a loop or two. When it dries, the strands that form
the "tent" around the fuse are musical when plucked, so I figured I
couldn't get any more tension than that in the product, horse or no.
But I've never tried spiking a cylinder as small as 30 mm dia.
I have, however, tried spiking kubisches kanonenschlagen roughly that
size. Would the techniques herein described for spiking cylindric
shells be appropriate for cubes like that?
Robert |
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| Bob... |
| Posted: Sat Oct 17, 2009 4:29 pm |
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On Oct 17, 7:41 pm, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:
Quote: The paste serves to lubricate the twine, yes, but that's not really its
primary function; it's to shrink and fix the twine when it dries.
Wouldn't water achieve the same shrinkage? So then what's the fixing?
Quote: I've never built the kanonenschlagen, but have made the East Indian style
of jute-wound box crackers.
How do they differ? Joe Gwotz once made a tetrahedral one.
Quote: IIRC, the Germans allow only black powder in their crackers (maybe that's
only the Brits...)
It's the Brits.
.... anyway... if it were the case, then instead of
Quote: spaced spiking, one would wish to spike like the Indian crackers (or a
Maltese shell) -- with a continuous frapping of twine,
I've never heard of any done any other way.
Robert |
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| Lloyd E. Sponenburgh... |
| Posted: Sat Oct 17, 2009 5:41 pm |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:d99f22d9-7134-49ac-
8868-f5eb8d79c0d9 at (no spam) g23g2000yqh.googlegroups.com:
Quote: I have, however, tried spiking kubisches kanonenschlagen roughly that
size. Would the techniques herein described for spiking cylindric
shells be appropriate for cubes like that?
The paste serves to lubricate the twine, yes, but that's not really its
primary function; it's to shrink and fix the twine when it dries.
I've never built the kanonenschlagen, but have made the East Indian style
of jute-wound box crackers.
IIRC, the Germans allow only black powder in their crackers (maybe that's
only the Brits...)... anyway... if it were the case, then instead of
spaced spiking, one would wish to spike like the Indian crackers (or a
Maltese shell) -- with a continuous frapping of twine, just as one would
properly dress the end of a throwing line, or attach guides to a fishing
pole.
LLoyd |
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| Lloyd E. Sponenburgh... |
| Posted: Sat Oct 17, 2009 5:45 pm |
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> fired this volley in
news:Xns9CA7C85033E66lloydspmindspringcom at (no spam) 216.168.3.70:
Quote: The paste serves to lubricate the twine, yes, but that's not really its
primary function; it's to shrink and fix the twine when it dries.
I might add that if the twine is properly tensioned, there will be little
or no sliding against any part of the shell. The only lubrication of any
value will be for your hands, which get rapidly "rope burned" dealing with
dry twine (especially in the first joint of the index finger and the second
joint of the little finger on whichever hand you favor).
LLoyd |
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| Lloyd E. Sponenburgh... |
| Posted: Sun Oct 18, 2009 6:31 am |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:baf44cd9-112f-4b34-
85e8-24075991b876 at (no spam) l9g2000yqi.googlegroups.com:
Quote: Wouldn't water achieve the same shrinkage? So then what's the fixing?
"Fixing" as in "fastening in place".
Wheat paste in thick-film layers is remarkably strong and resistant to
moisture once dry. Once the paper and string have thoroughly dried, they
lock together such that it's quite difficult to disturb the spiking
pattern without seriously damaging the shell.
LLoyd |
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| Bob... |
| Posted: Sun Oct 18, 2009 2:22 pm |
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Quote: Bob <robg... at (no spam) bestweb.net> fired this volley in news:baf44cd9-112f-4b34-
85e8-24075991b... at (no spam) l9g2000yqi.googlegroups.com:
Wouldn't water achieve the same shrinkage? So then what's the fixing?
"Fixing" as in "fastening in place".
Wheat paste in thick-film layers is remarkably strong and resistant to
moisture once dry. Once the paper and string have thoroughly dried, they
lock together such that it's quite difficult to disturb the spiking
pattern without seriously damaging the shell.
LLoyd
So why doesn't that defeat the function I've heard of spiking a star
shell, which was controlled inflation? Correct me if I'm wrong, but
wasn't the idea different from the spiking of a maroon, which is to
maintain as small a volume for as long as possible? That in a star
shell, by contrast, the string is supposed to break at some point and
unwind while the shell inflates and bursts like a balloon instead of
shattering? ISTR that being explained at the panel on "Paper, Paste,
and String", subtitled, "With Tape, Glue, Imagination, and Foam" which
AFN sells a recording of.
Robert |
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| Lloyd E. Sponenburgh... |
| Posted: Mon Oct 19, 2009 5:36 am |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:73747e30-ac3c-4ed4-
80fd-9f035ed39453 at (no spam) x37g2000yqj.googlegroups.com:
Quote: That in a star
shell, by contrast, the string is supposed to break at some point and
unwind while the shell inflates and bursts like a balloon instead of
shattering?
Bob, I have a different theory. Given the (lack of) elasticity of pasted
paper (or styrene plastic) and paste-soaked twine already stretched near
its breaking limit, I think a shell couldn't possibly inflate like a
balloon.
In my mind experiments, I see a star shell as pressurizing without
yielding until the casing finally fails.
At that point, the large sail area, low mass shell housing is ejected
away from the center, leaving (if you will imagine this in your mind's
eye) a mass of stars immersed in a beginning-to-expand ball of hot, high-
pressure gas.
This "fuzzball" of gas/stars expands about its own center of mass (as it
must without any external mechanical constraints), giving a symmetrical
burst. The symmetry is only permitted if ALL of the shell fails
simultaneously; otherwise, the stars will "squirt" out one side. This is
why a rapid pressure rise is desirable, and why a slow rise-time burst
will create an asymmetrical shell casing failure.
This theory explains to me why even a half-shell of stars will give a
round break. I challenged this at one FFFF (taking side-bets for fun).
We "group-built" a daytime smoke 6" plastic shell. One half - exactly -
was filled with Shimizu's naphtalene black chrysanthemum stars. The
other half was filled with a mixture of 4FA and mealed hulls, with some
4FA sprinkled in among the stars, as well. It was broken with an 8g
flash bag centered in the shell (not centered in the stars).
With observers posted all over the field, the unanimous opinion was that
it gave a perfectly symmetrical, round break. (and I grinningly picked up
about $10 of fun money!<G>)
I do not understand any other mechanism that would allow that, than the
theory I've stated.
LLoyd |
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| Lloyd E. Sponenburgh... |
| Posted: Mon Oct 19, 2009 5:39 am |
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Bob <robgood at (no spam) bestweb.net> fired this volley in news:73747e30-ac3c-4ed4-
80fd-9f035ed39453 at (no spam) x37g2000yqj.googlegroups.com:
Quote: That in a star
shell, by contrast, the string is supposed to break at some point and
unwind while the shell inflates and bursts like a balloon instead of
shattering?
I should have added this: If you locate the shell parts of a shell that
bursts hard and round, you will find hardly a piece of it larger than a few
percent of the shell's surface area -- and no signs of stretching.
LLoyd |
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