Monday, 25 February 2008

Balancing a plied yarn

Last week I had spun and plied a fine grey Shetland yarn, when I had wound a skein and removed it from the small niddy-noddy, it twisted over on itself, as shown.

My heart sank at this. I'd spent a couple of evenings preparing this yarn, spinning one singles one evening, the other and plying on the next. I hoped the problem might be solved by washing the yarn and then drying it with a weight to pull it straight. This was not to be - oh no - no such happy resolution. Nothing like. I dropped the yarn in a bowl of hand-warm water and it straight away seemed alive. It squirmed.

I leant over the bowl of water and stared at the skein anxiously, it didn't look right at all. It had kind of curled up in the bowl, like my cat in his basket. Skeins don't normally do this. They normally kind-of stretch out and float, like when you return a strip of seaweed to the sea. I pulled out the unhappy little skein, I hung it over a rack and dried it with a weight, but even with the weight hanging from the wet skein, it wouldn't straighten out.

Do you see its fancy twirls and squiggles? Not the sort of yarn I wanted. Not as good as my previous attempts at a balanced, fine yarn. One of the oddest yarns I've produced.

It reminded me of another skein, tucked away in a drawer for a couple of years.

No, this is not knitted! Yes, it does look like moss! I was trying out an idea, plying a yellow yarn with a green, thinking of knitting a sample square to try out a jumper yarn. When I took it off the niddy-noddy, my beautiful yarn turned into the strange coil you see above. It's very elastic, makes a nice warm neck collar, but will never be knitted!

How was this achieved? I had plied the yarn the same way it was spun. Normally, to ply a yarn the spinning wheel direction is reversed. The twist in a singles yarn gives it kinetic (stored) energy. The straight fibres fight against the spinning. A singles yarn can be set, just like curling your hair with old fashioned curlers: wash and dry under tension. In a plied yarn, two singles spun the same way are plied with opposite twist. The plying "balances" the energy in the singles with a twist that pulls the other way.

I remembered that Mabel Ross's Handspinner's Workbook had a section "Balance in Yarn Spinning". Very much aware that I really don't understand properly how plying works, I went back to this book. She describes how a balanced yarn needs to be plied, and being a mathematician, she gives an equation.

To summarise, plying a yarn the opposite way to the twist in the singles, removes of half the twist from each of the singles yarns.

To achieve balance,
the twist per inch in the plied yarn
must be equal to
the sum of the remaining twist in the singles.

9 tpi in each of two singles, plied 6 tpi the opposite direction, leaves two singles each with 3 tpi. 2 x 3 tpi = 6, the same tpi as the plying, and so a balanced yarn.

O.K. this is not the simplest concept in spinning. But Mabel Ross has done what no-one else seems to. She looked at what happens, analysed it, and made a description that if you can follow it enables you to ply a balanced yarn every time.

Big sigh. I had to stop, think, calculate, but it was worth while. I got some black Shetland, just a little (I didn't want another whole skein going wrong!), and prepared a couple of short lengths of singles yarn, then plied, putting in 2/3rds the twist of the singles. It worked.

What is more, it's a good fine yarn. I didn't spin enough to see how many times it would wrap around one inch of my ruler, but there were 20 wpi in the half inch.


Peg in South Carolina said...

I'm sorry about your mis-plying but you created a wonderful post about it! When I ply I generally end up putting a bit more twist in than when I spun the original yarn. These test,then, is to dunk it in water and hold it up. Mine almost always comes out absolutely straight. Your quote from Mabel Ross now shows me why my plying works!

Leigh said...

I think Mabel's plying twist concept is hard to understand at first, but like you say, it works, and that is usually the best selling point.

Laritza said...

I had the same thing happen with Rambo fleece. Margaret Stove says in her book Working with Merino and other fine Wools, that it is because the fibers are pulled while plying, then they want to go back to their original crimp. Shetland does not have as much crimp as Merino and Rambo so your explanation is the correct one for your yarn. Not for mine....I think! That yarn is on the loom right now. It was curly as your green skein is and it took a lot of tugging to get a "straight" warp. I do wonder what I going to happen when I take the tension off! I might have a boucle yardage! We'll soon find out since I am weaving the last yard of warp. At this point all I can do is hope for luck......

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Barbara said...

Hi Dorothy, Thanks for reading my blog and for comments .Hope you've sorted out that neckline ! The pattern for the Elizabeth Zimmerman baby surprise jacket, but an illustration only, of the adult version are in her " Knitting Workshop "book. The pattern was once published in "Spin Off" and a friend photocopied it . Will try and get it to you if you would like it

Helen said...

Hi Dorothy I understand your frustration about your yarn. When I di a lot of spinning I found a balanced yarn seemed to happen with experience but it is just fascinating to read the mathematical explanation for it! Mty trouble is that I liked your sad little yarn and it can be just great for free form crochet to add textrue.

In answer to asking Enys about planting seeds I am trying very hard to twist her arm to join me on the bloog adding her comments. So I will send her an email and ask her to write something down for you. However I know she has a heated propagator and an enormous greenhouse you could hold a party for twenty in!