rope, fire and safety

[KnotNow!]

Hi,
  In the Telephone Industry we fuse glass fibers.... but we do it for light tranmission, not strenght.  I use heat to fuse the braid of synthetic cord to make it solid, often to help in tucking and end or often to finish ends when the knot is done.  I just used heat to fuse the tapered yarns of a eye splice... so not long threads could stick out and no short threads could pull into the splice.. but...  As an end to end joining.. a true splice... I can see no way get much tensile strength.  It is an tempting idea.  I may make up a long splice in some of the 7mm "stinkum" cord we have here and at the junction of two strands I try to fuse them with heat.  Then I might try to destroy the splice, to see what I get.  My guess is that fused ends do not transmit load up the thread, yarn and strand far enough to take advantage of the friction within a thread, yarn and strand.  Have you watched rope fail?  Friction is a big factor as to why rope works in the first instance.  This is why there is a length where the long splice works no matter how sloppy you make your tucks.  I suspect we could join two lines, carefull sheared to 90 degrees and fuse them to melt into the line for several turns and perhaps have a homonogous splice.  However since the line relies on flex and transfer of forces through friction to be strong.. I think it will still break.  A good avenue to explore.  I am sure Carol was just fusing the end of the cord to prevent unraveling.  The ever present zippo back splice.  But it sent me to thinking....

[Willeke]

What I missed in the replies so far, (or did I overlook it?) is that in many cases it is posible to use sticky tape. When working it will keep the ends of most kinds of string sealed. When applied right it does not need to make the string thicker by much, sometimes it even reduces the size of the string. Apply one and a bit, or two layers, of tape, well streched and under tension, before cutting the string.
It is no solution at the end of a project, but it should halve the need to melt.

Willeke

[alana]

awesome discussion,
i will use soldering iron instead of shopping for a hot knife   

[KnotMe]

Here's a video I made for a class that I was teaching to adults.

When I have just a few ends to singe or one join to make, I often (so lazy!) fire up our kitchen stove (gas) with the fan on full blast.

[JohnC]

I prefer to use a gas cigarette lighter, it gives a small stable flame.
Light the flame and bring the end of the cord close to the side of the flame.  When the cord is still about half to one mm away from the flame, the fibres will start to melt.
Gently heat the end of the cord this way until all of the end has melted over.
Dowse the flame and dab the melted end onto the side of the lighter - it will stick.
Quickly drag the cord away from the lighter, this will drag off any blob from the end of the sealed cord and neck the fused polymer into a taper. 

  (Bold added to quote)
I find this interesting, but is "the side of the lighter" the plastic side (if it's a Bic you mean) or the side of the metal top part? (which can get quite hot). I prefer to ask than to experiment - to avoid a damaged lighter.

Or is this the cold flat steel side of a Zippo? I had one 30 years ago when I was a smoker but I don't think I could afford one now. In this part of the world they're collectors' items.

[mcjtom]

There is this rope end sealing technique using superglue instead of fusing it.  I think people use it on rope materials that wouldn't fuse well, but it should work on nylon or polyester just as well, I think. I haven't tried it yet.  Would anyone have any experiences with it to share (e.g. would superglue be the adhesive of choice - it's thin which is probably good for penetrating fibres, but wouldn't it be a little stiff when set)?

[roo]

There is this rope end sealing technique using superglue instead of fusing it.  I think people use it on rope materials that wouldn't fuse well, but it should work on nylon or polyester just as well, I think. I haven't tried it yet.  Would anyone have any experiences with it to share (e.g. would superglue be the adhesive of choice - it's thin which is probably good for penetrating fibres, but wouldn't it be a little stiff when set)?

If you are sealing rope on a regular basis, using superglue could start to get costly.  It doesn't keep well in bulk and so tends to get sold in teeny tiny single-use tubes.

[Dan_Lehman]

Late to the discussion, but Roo's point about frequency
is good : I don't know ... , but there is special "liquid whipping"
goop that might serve also for the light-duty fusing of ends
which I think is the point here?  (I only know of some of the
play ropes I inherited ... being so whipped, and being nice
in the non-bulky sure termination.

ANNND, this stuff is likely a bad thing to inhale.


 

[mcjtom]

Did anyone have any luck with other types of glue, other than cyanoacrylate/superglue, for practical sealing, not necessarily decorative?  Also, electrical shrink tubing has been advised, but I'm not sure if they will last.

[SS369]

One of the neat ways to seal the end(s) of rope or cord that I employ is to first wrap the end(s) with tape, usually of the masking variety. Then I will cut the end squarely through the tape to eliminate potential fraying. At this point I have the options of melting the ends, if meltable or sealing it with some adhesive. If one is in a hurry and only doing a few, then I would chose "super glue". The tape keeps it neat and at the end, only migrating a bit into the core and sleeve ( if that is the construction). I can then remove the tape or not.
The above is for end sealing, not splicing, although it might work as well. I just have never worked it that way.
Aside from super glue there are other solutions to be tried. I have used a product called "Modpodge" (which I believe is some kind of pv glue. It smells similar.).
Heat shrink tubing, if applied well, will last a long time through rough use. It is applied to climbing rope ends frequently, although the rope ends are melted also.
SS

[Dan_Lehman]

I have used a product called "Modpodge" (which I believe is some kind of pv glue. It smells similar.).

Right, and it would be on the order of Elmer's glue.
(And I've some "Tacky" glue of like composition.)

Heat shrink tubing, if applied well, will last a long time through rough use.
It is applied to climbing rope ends frequently, although the rope ends are melted also.

And like a good moderate length whipping
it can stiffen the line enough to be an effective
(--when <stuff> happens!) stopper in a knot
--not to depend upon it, but it might come into
play sometime!  (In non-critical uses, I do sometimes
stuff just a pretty-rigid-whipped tail to be nipped,
say of the hitching line in a Lapp bend.)

 

[mcjtom]

Heat shrink tubing, if applied well, will last a long time through rough use. It is applied to climbing rope ends frequently, although the rope ends are melted also.
SS

There is also another curiosity, which I've never used, but seems to be widely available - heat shrink tubes lined with hot-glue adhesive.  I'll try it once I get my hands on it - may be an ideal solution to rope ends' sealing (you never know untill you try...).

https://www.youtube.com/watch?v=wDwl5EcOumw

[SS369]

Heat shrink tubing, if applied well, will last a long time through rough use. It is applied to climbing rope ends frequently, although the rope ends are melted also.
SS

There is also another curiosity, which I've never used, but seems to be widely available - heat shrink tubes lined with hot-glue adhesive.  I'll try it once I get my hands on it - may be an ideal solution to rope ends' sealing (you never know untill you try...).

https://www.youtube.com/watch?v=wDwl5EcOumw

I'm wondering how those tubes would do as a splicing... ?
You won't untie those !

[alana]

i hold a cord end with a clothes peg near a flame,
then pull the cord through the clothes peg hole,
including pausing for 3 seconds (3mm polyester cord) with the melted end just inside the level of the clothes peg face,
then yanking it out.

this has evolved to just pulling the melted end through the peg,
and then again with the cord rolled 90 deg.,
which smooths the sides that have been pinched a bit by the clothes peg profile.

in the same way as knotme discussed,
i join ends with lighter or candle, and just put the two ends together,
then have had success with neatening the join using pliers 

pic:
my clothes peg (reva australia),
3mm v.b cord finished end,
joined ends shaped by pliers,
and my igkt scale / colour card ! 

[mcjtom]

I just discovered flameless whipping.  I have this 0.7 mm low-stretch, braided polyester cord (MBS of some 10 kgf) - I think made as a radio dial string.  I started tying the Constrictor (#1249) - can be tied really fast by flipping a loop over the rope end - or the #1253 - with 3 wraps around the rope - on small rope ends, snugging it tightly by pulling the ends with two screwdrivers in Marlinspike(?) hitches, cutting the ends of the twine short, and trimming the rope end bit closer to the whippings.  I was rubbing some universal UHU glue around whipping and at the tip of the finished rope end for good measure, but it may not be necessary.