Soap Bubble Wiki

Bubbling with Diamond Braid Cord[]

About the Cord[]

Diamond braid cotton cord, sold as utility rope or sash/clothes line, can make great bubbling material. But it takes some work to make it work well. Coring is most important. They all have a core of man-made fibers, despite the "100% cotton" claim you might see on the label. This stuffing is intended to make the line stiff, which is the opposite of what a bubbler usually wants in a cord.

Even with its core removed, it's still fairly stiff. In tri-strings, closing bubbles is difficult unless a weight is attached. In garlands, its stiffness prevents the individual loops from laying flat as you lift them from the bucket. Their bubble films can be blown out by fast winds or they can prematurely release a trickle of bubbles, taking away from the drama of the garland's opening.

Hypotheses[]

I had a hunch that I could increase the limpness of diamond braid cord by a combination of bleaching and abrading. I hoped that by partially dissolving the cord's fibers, its braid would loosen and garland loops made from it would lay flatter as I lifted them from the bucket. Abrading tends to loosen braids too. It artificially weathers a cord, causing some of its fibers to break. This fuzziness seems to improve performance. I also suspected that treatment with sodium carbonate might have the opposite effect. Since it tends to "puff out" cotton fibers, it could tighten the braid, making it stiffer and possibly slowing the release of bubble solution.

Here, I attempt to put these ideas to the test and study the effects of various popular bubble cord treatment methods on diamond braid cord. My initial goal was to construct a garland having alternating loops made from the same cord but treated in different ways, so as to reveal performance differences. The results were somewhat inconclusive. That inspired me to see what physical properties I could track over the course of the cords' treatments.

Side-by-side Garland Loop Testing[]

Garlands are great for comparing bubbling materials. Contiguous loops of differing material soon show their strengths and weaknesses. I built one of alternating loops of diamond braid cord that had been treated differently. I cored, boiled, and washed 9 lengths of diamond braid cord. Three were soaked in sodium carbonate. Another 3 were harshly bleached. Then they all were abraded over a sharp (90 degree) edged and washed once again, to loosen their braids and artificially weather them.

Materials[]

CordAndLabelFx

'Wellington Light Load Braided Cotton Multi-purpose Rope, 13 lb. load limit'

The cord I used is labeled 'Wellington Light Load Braided Cotton Multi-purpose Rope, 13 lb. load limit'. It's sold at K-Mart.

The bubble solution I used was a 13:1 (water:Dawn Pro) mix. Each gallon contained 3 grams BLM, 1 tsp sodium bicarbonate, and 1/2 tsp anhydrous citric acid.

For sodium carbonate treatment, I used a product labeled, "Arm & Hammer Super Washing Soda". It has no ingredients list. Neither does Arm & Hammer's website. Its caution label warns that it contains sodium carbonate. My understanding is that it's very near pure sodium carbonate.

The bleach I used contained 8.25% hypochloride. It was Wal-Mart's "Great Value 33% More Concentrated" variety. Bleaching methods varied as described.

All water was from the tap, except distilled water was used to make the BLM.

Cord Preparation[]

I measured and cut nine 27 inch (69 cm) lengths of cord, and removed both the polyester and cotton strands from their cores.

I boiled all 9 for 1/2 hour. Then I soaked 3 of these overnight in sodium carbonate, and treated another 3 for 20 minutes in a hot 50/50 solution of bleach and water. I left 3 lengths untreated.

DryingCordsFx

Drying diamond braid cords on the patio of Ceska Beseda on a late summer afternoon.

I then soaked them all in a strong solution of water and Dawn (8:1) for 1/2 hr, rinsed them thoroughly, and hanged them to dry.

 
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Treated cords before abrading

This is how the cords appeared after drying. The bleached lengths were about 1/2 inch shorter than the others, which were about 23 1/2 inches (60 cm).

 
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Cords after abrading

This is how the cords looked after abrading across a wrought iron rail of a wine rack. Afterward, all the cords were about the same length - between 25 and 25 1/2 inches (63-65 cm).

Limpness Observations[]

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Dry loop limpness

I arranged one cord from each group in a pants hanger with each one's ends face-to-face according to their braid.

 
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Cord limpness observations with water and bubble solution.

I soaked them for several minutes in plain water and observed their limpness. The bleached cords were visible limper. After 5 dips in a BLM-based bubble solution, the relative limpness of the bleached cords was also apparent.

Garland Construction and Initial Testing[]

ConnectionSwivelDetail

Test garland connection detail

I constructed a garland with repeating sequences of untreated, Na2CO3 treated, and bleached cords. Each loop had about a 9 inch (23 cm) top-string. There was no clear winner in this configuration. All loops occasionally blew out prematurely, but even in soft winds the garland performed poorly overall. This particular 13 lb diamond braid is simply not heavy enough for garland loops of this size.

 
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Test garland

I divided each loop in half using garden tape and had much better results. The bleached loops blew out far less often than the others when being raised from the bucket. However, when all or most loops had intact films upon opening, the bleached loops performed worst of the 3 types. The untreated ones performed best. After a few dozen dips, the bleached loops appeared noticeably larger than the others. The stiffness of the untreated loops effectively made them smaller.

 
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Test garland with extra spacers

After three test sessions in varying wind conditions, and rinsing, squeezing-out, and drying the garland between each session, the bleached loops had measurable 'grown' by about 10% in length. Their limpness had improved too, whereas that of the others appeared unchanged. To even the playing field, and account for the larger bleached loops, I added more garden tape spacers dividing each bleached pair.

Results[]

Overall, the bleached loops still underperformed the others, although to a less dramatic degree. In faster winds, the more I delayed opening the garland after raising it from the bucket, the better the relative performance of the bleached ones. The other ones blew out more often, or lost a significant amount of their solution unless I hurried the deployment of the rig, and sloshed a lot of juice around. Despite my adjustments to the sizes of the loops, there were still shaped differently.

Quantitative Analyses of Treatments[]

To get a better idea of the effects of these various treatments on this cord's properties, I conducted another series of tests. No bubbles were harmed in the process of conducting these experiments. Neither were any created. I only wanted to see what physical properties might change in the cord between the various phases of treatments.


I began with nine 26 inch lengths of raw rope, and brought all 9 through the same series of treatments: Coring, washing , boiling , sodium carbonate soaking , bleaching , and abrading.

Treatment Phases[]

Coring[]

CoringCordFx

Diamond braid's core

Removing the cores of short lengths of cord is pretty easy but still requires some attention. The type I used had both cotton and man-made fibers in its core. If you apply too much force pulling it out, some of its fibers can break (especially the cottons ones) and remain trapped inside. It's good to inspect their ends after coring, to make sure there are no stragglers.

I wet each cord and held it up to a bright light, to see if any pieces of core remained. It didn't appear to be the case. However, I did see a few specks of debris about 1 mm in length that seemed to be trapped inside.

 

Washing[]

Before washing, raw cored cord is able to hold a significant amount of liquid in its hollow center. If you raise a length from a liquid and keep its upper end closed, it holds much more liquid than if the top is left open. You can sometimes hear air being drawn in through the top, if you restrict its opening.

All cords were washed after each treatment.

 

Boiling[]

All were boiled for 1/2 hour in tap water. I bundled their ends with string to minimize the braids' unraveling.

 

Sodium Carbonate Treating[]

All cords were soaked in a 15:1 solution of sodium carbonate (washing soda) and water for 10 hours.

 

Bleaching[]

Bleaching_Diamond_Braid_Cord

Bleaching Diamond Braid Cord

Bleaching Diamond Braid Cord

For this, the cords were placed in a 2 cup measuring glass and covered with bleach. An amount of hot water equal to 1/2 their combined volume (200 ml) was added (100 ml), and the glass was set in a pan of freshly boiled hot water for 40 minutes.

During this process the cords fizzed with bubbles as the bleach dissolved their fibers. At first it was a fine foam, and toward the end more like a glass of champagne.

 

Abrading[]

AbradingFx

Abrading diamond braid cord on an old wine wack

I abraded all 9 lengths against a 1/8" (3.2 mm) rail of a wrought iron wine rack, giving each 20 passes across its top and bottom. While doing this, a fine whitish dust was generated as some cotton fibers were shed. Much more of this dust was created by the bleached lengths.

 

Liquid Release Tests[]

My goal was to quantify how quickly cord was able to drain liquid - water and bubble solution - at various phases of treatment. After much experimentation, I arrived at a method that seemed to yield reasonable estimates.

Methodology[]

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Drip test setup

All 9 cords were soaked for 15 mins in room temperature water or solution. Each cord was raised by one end from the liquid, allowed to drain for 2 seconds, and then weighed. This was repeated two more times, and the averages of the 3 trials were averaged.

This established the 'baseline' representation of a fully soaked cord. It's somewhat arbitrary, but my attempts to measure this baseline prior to 2 seconds yielded wildly variable results, and a mess.

I then repeated this tests, weighing the cords after 12, 22, and 32 seconds had passed, in order to determine how much liquid was released relative to the baseline - after 10, 20, and 30 seconds had passed, respectively. Although this doesn't really simulate what happens when a cord releases solution into a bubble, my hope was that it might reveal some interesting differences among treatment methods nevertheless.

 

Treatment Effects on Cord Length[]

Treatment Effects on Cord Length
Treatment

% Change in Length

vs. Previous Treatment

% Change in Length

vs. Uncored

Coring -6.9 -6.9
Washing -6.0 -12.5
Boiling -12.5 -23.5
Na2CO3'ing -1.2 -24.4
Bleaching +6.8 -19.2
Abrading +25.3 +1.9

Treatment Effects on Cord Weight[]

Treatment Effects on Cord Weight
Treatment

% Change in Weight

vs. Previous Treatment

% Change in Weight

vs. Previous Uncored

Coring -66.26 -66.26
Washing -0.91 -66.56
Boiling 0.00 -66.65
Na2CO3'ing -0.46 -66.72
Bleaching -22.58 -74.23

Abrading

-2.45 -75.61

Drip Release Tests - 2 Second Baseline[]

Drip Release Tests - 2 Second Baseline Weights (grams)
Treatment

2 Second

Baseline

Weight

Dry Cord

Weight

Solution

Weight

Solution %

of Baseline

Cored 12.64 2.20 10.44 82.60
Washed 12.04 2.18 9.86 81.89
Boiled 10.97 2.17 8.79 80.13
Na2CO3'ed 10.75 2.17 8.58 79.81
Bleached 10.41 1.63 8.78 84.34
Abraded 10.50 1.59 8.95 85.24

Drip Release Tests - Solution Release Over Time[]

Drip Release Tests - Solution Release Over Time
Treatment

Baseline

Solution

Wt (g)

%Released...

Secs 0-10

Secs 11-20

Secs 21-30

At 20 Secs

At 30 Secs

Cored 10.44 21.07 12.01 6.48 30.56 35.06
Washed 9.86 19.78 10.11 7.03 27.89 32.96
Boiled 8.79 20.14 8.40 5.60 26.85 30.94
Na2CO3'ed 8.58 20.75 7.06 4.91 26.34 29.95
Bleached 8.78 23.23 10.24 6.94 31.09 35.88
Abraded 8.95 24.69 11.28 7.53 33.18 38.21

Observations[]

Freshly cored cord appears to have the best properties, but of course, after 1st use, it's no longer fresh. It's washed. The greatest incremental improvement among these treatments seems to have been accomplished by bleaching. By also abrading, the greatest amount of solution was released in the 1st 10 seconds, the period during which most bubbles are made. It's interesting to note that despite the cord losing more than 25% its weight after bleaching and abrading, the amount of solution it could hold slightly improved.

More Questions[]

This exercise creates a LOT more questions than it might have answered. How would the cords release bubble solution if they were actually making bubbles, rather than just draining? How would the cord behave if either the Na3CO3 or bleaching treatment was omitted?

I saw hints of cord loading during some tests, where it seemed the cords grew slightly heavier after repeated dunks in solution. I'd like to test this phenomena too.

As they say: "Further study is needed."