bend in cord elastic
Joy Beeson
When I put flat elastic into a casing, I sew the ends together, but
when I use cord elastic, I just tie a knot.
The last time I had to open a casing because the knot had come untied,
I said well, duh! -- a square knot is a *binding knot*; I should have
been using a bend.
My first impulse is to use a sheet bend, mainly because I can tie one
without consulting a book and sometimes don't even think about the
rabbit and the tree*, partly because the sheet bend is also called
"weaver's knot", which suggests that it's particularly suitable for
textiles.
The only other bend that I know about is the carrick bend, which I
reject because (a) I don't know how to tie one (b) its main virtue is
that it tightens correctly under strain, so it's safe to tie in ropes
too thick to tighten by hand (c) both ends stick out at right angles
to the standing parts. I'm slightly unhappy with the sheet bend
because one end sticks out.
So is there a better bend for a cord that rubs back and forth inside a
tube? Since weavers tie sheet bends in warp threads that get rubbed
hundreds of times before they get woven in, I suspect that it will
turn out the be the winner -- but I do like to have a better reason
than "It's the only knot I know."
footnote:
* It would be much better to teach children by pointing out the way
the curves interlace and hold each other than by distracting them with
mnemonics. Takes more time to explain, but it would stick better.
Joy Beeson
--
joy beeson at comcast dot net
http://roughsewing.home.comcast.net/ -- sewing
http://n3f.home.comcast.net/ -- Writers' Exchange
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.
rootw...@yahoo.com
> When I put flat elastic into a casing, I sew the ends together, but
> when I use cord elastic, I just tie a knot.
>
> The last time I had to open a casing because the knot had come untied,
> I said well, duh! -- a square knot is a *binding knot*; I should have
> been using a bend.
>
> My first impulse is to use a sheet bend, mainly because I can tie one
> without consulting a book and sometimes don't even think about the
> rabbit and the tree*, partly because the sheet bend is also called
> "weaver's knot", which suggests that it's particularly suitable for
> textiles.
>
> The only other bend that I know about is the carrick bend, which I
> reject because (a) I don't know how to tie one (b) its main virtue is
> that it tightens correctly under strain, so it's safe to tie in ropes
> too thick to tighten by hand (c) both ends stick out at right angles
> to the standing parts. I'm slightly unhappy with the sheet bend
> because one end sticks out.
>
> So is there a better bend for a cord that rubs back and forth inside a
> tube? Since weavers tie sheet bends in warp threads that get rubbed
> hundreds of times before they get woven in, I suspect that it will
> turn out the be the winner -- but I do like to have a better reason
> than "It's the only knot I know."
>
Tie a Zeppelin Bend, set the bend firmly, and trim off the ends. You
could also seize the ends down if you want, but I think you may be
overly concerned about it.
http://www.geocities.com/roo_two/Zeppelin.html
Mnemonicized for your convenience.
Joy Beeson
> Tie a Zeppelin Bend, set the bend firmly, and trim off the ends.
> http://www.geocities.com/roo_two/Zeppelin.html
Now that is one cool knot -- rather like a symmetrical weaver's knot.
Shouldn't be too hard to remember once I've done it a few times.
> You
> could also seize the ends down if you want, but I think you may be
> overly concerned about it.
My spouse sometimes says that he needs my "dainty fingers", but I
don't think they are quite dainty enough to seize down cord elastic.
<firmly stomps on temptation to grab cord elastic, sewing thread,
prove above statement wrong>
> Mnemonicized for your convenience.
Lessee -- one rabbit comes up out of the hole, a different rabbit
dives in, no dogs or trees in sight.
ford....@embarqmail.com
> The above message is a Usenet post.
> I don't recall having given anyone permission to use it on a Web site.
You could try a "water knot", basically an overhand knot in both
strands, but with the strands coming from opposite directions into the
knot, or a "fisherman's knot", two overhand knots that slide together
and lock.
Good luck,
Ford Walton
Dan Lehman
> ...
> when I use cord elastic, I just tie a knot.
>
> The last time I had to open a casing because the knot had come untied,
> I said well, duh! -- a square knot is a *binding knot*; I should have
> been using a bend.
This is utter rubbish: the Square/Reef ('squaREef' in my
shorthand :o) knot
is quite a *bend* (in the sense Ashley et al. have tried to force a
meaning)
-- it is a knot that joins two ends of rope(s). Plain & simple and no
point in
trying denying. Whether it's the **right** knot for the job is a
separate issue;
it is THE right *bend* for tying together broken rubber bands (pull on
all parts
to set), possibly because of the setting process for it.
It sounds as though for your circumstance/materials you should try the
Fisherman's KNOT (nb: NOT "bend", which is a *hitch*, as per Ashley
and
before him) -- the Overhands around each other's S.Parts that are
pulled
together to lock. This knot should be able to be set well compact and
with
a good profile for the sort of rubbing you describe; it is the "bend"
of choice
in commercial-fishing lines because of its simplicity, general
strength, good
resistance to abrasion (the neatly parallel parts make a protective
surface),
and alignment of the ends along the S.Parts where they can be secured
by
"hog rings" or tape or seizing. (FYI, some testing found that this
knot can
slip at high loads in nylon kernmantle dynamic & low-elongation
ropes. FYI)
You should tighten each Overhand component separately to try to get
the
sort of drastic size/diameter reduction such elastic material will
give into
the component before then drawing them snug together in the knot,
which
should preserve their tightness.
The suggested Ring Bend / <traced Overhand knot> / Water knot has the
same form, but draws up with a difference depending on which ends are
loaded (i.e., those leading to extreme ends of knot body or those
turning
interior to this, which will give a slightly better (more even)
shape).
Otherwise, which is less bulky, return to the squaREef but this time
put
special emphasis on setting it tight (pull on all ends) & well, and
then
secure the ends with seizing (good excuse to employ a long-lost
technique,
no?). The beauty of this joint is its small size.
> My first impulse is to use a sheet bend,
I'd expect you'll have no luck here -- it's not secure, not a jamming
knot.
And it's one end sticks out rather perpendicularly.
> The only other bend that I know about is the carrick bend, which I
> reject because (a) I don't know how to tie one
But that should be at most a couple e-clicks away from you!
> that it tightens correctly under strain, so it's safe to tie in ropes
> too thick to tighten by hand
This sounds like nonsense / speculation to me: a great many big ropes
are actually much more conducive to bending (i.e., folding) than say
"static" (low-elongation) caving ropes, which stubbornly resist
curving
around 1 diameter and even 2(!). Moreover, one really wants to ensure
a proper setting of the knot and not leave to the vagaries of
capsizing
by loading -- which might see an end pull free or too nearly so.
Finally,
when tied in the very stiff, hard-laid ropes of those Alaskan crabbers
shown on The Deadliest Catch, it is tied in a different manner than is
shown by most sources (which are largely echoes of each other): one
side is folded into a sort of Crossing-Knot (Munter Hitch) form, and
then
the other end is rove through this accordingly (though this allows for
easy
goofs until practised & learned).
But you're right re this knot's not meeting your shape needs.
> * It would be much better to teach children by pointing out the way
> the curves interlace and hold each other than by distracting them with
> mnemonics. Takes more time to explain, but it would stick better.
No need for this to be either/or: do both, the one ensuring correct
tying
of the knot, the other giving fuller understanding of it.
--dl*
====
Joy Beeson
> I haven't access to any post on this subject prior to this one (10
> July, 2009), so I am wondering if the Zeppelin bend was considered in
> this thread?
When I finished my new knickers, I tied a Zeppelin bend in the elastic
of one knee and a sheet bend in the elastic of the other. I'll report
back if one or the other fails.
I think I like the sheet bend better, as it's a trifle smaller. But
I'm glad to have learned the Zeppelin bend. (Not that I can tie it
without referring to my print-out from Notable Knots.)
(Notable Knots is a splendid Web site, by the way. I must get around
to linking to it on the _Rough Sewing_ website.)