blocking question

Every instruction I've read on blocking tells you to use a mild detergent in tepid to warm water which is how I do it but why the detergent, what purpose does it serve? It's not like the yarn is dirty.


Tallguy's picture

Oh, yes, it is. You'd be surprised how much dirt that yarn will pick up, just by you touching it with your hands. Honest! Or do you stop and wash your hands every few minutes? Wear latex gloves?

The purpose of the soap or detergent (not the same thing) is to break the surface tension of water so that the fibres will absorb the water. Otherwise, the water will only sit on the outside. You want the fibres to get wet inside, to allow the bonds to break and shift around, so that your stitches all come out nice and even, the fibres all settle in, get comfy with each other, and it will all look like it just belongs that way! You get a truly professional finish. Of course, this is only for plant and animal fibres... I don't think there is anything you can do to help synthetics.

Joe-in Wyoming's picture

Once again, TallGuy, you are a great fount of wisdom and common sense. Thank you. -- Books, knitting, cats, fountain pens...Life is Good.

Books, knitting, cats, fountain pens...Life is Good.

Kerry's picture

I tend to use detergent only when I know the yarn has been oiled, otherwise it's just warm water.

New York Built's picture

Tallguy is absolutely right. The structure of animal fur and hair are like nested "cups" connected with a central string. The cup edges can be curled, sharp, spikey, soft...depends on the species and the conditions of life. Water swells the fibers, the cups are repositioned into the direction they are bent, and they lock in. Vegetable fibers respond similarly but with smoother surface structures and little "give". Insect fibers are like strands with little surface extruded pasta...they require little water, a spray, and they are done.

As to synthetics, concentrated acids, matches and shredders work quite well. Using common sense, well-ventilated areas and the correct amperage...those pesky synthetics will never be a problem for very long.

“There are those that do and those that don’t”
“Those that will and those that won’t”

Every person I encounter teaches me more about myself. Without whom not.

scottly's picture

Thanks guys! Very interesting. So what do find to be the best detergent or soap to use? I've been using shower gel because I think it's easier to rinse out and leaves a pleasant scent.

chipsir's picture

I always use soak or eucalan for the exact reason that you do not have to rinse. it also contains lanolin so it conditions the fibres as well, the only time I use detergent is to felt.

scottly's picture

Where can one find Soak or Eucalan?

QueerJoe's picture

Here's the first Google result I got for "soak wool wash" (I love using Soak...the fragrances are very mild and still add something to the garment):

james's picture

On the topic of soap/detergent . . . why do you not use a wool wash like Soak or Eucalan? They are gentle and require no rinsing. I use them for blocking as well as everyday laundering of my sweaters and socks.

Crafty Andy's picture

Visit Crafty Andy's Blog
Blocking by detergent and submersion is a typoe of blocking, you can just steam block as well. If it is a natural fiber washing it will give it it's final form and youwill see if your stitches' gauge is correct. If you have something that it is stretchy and has no memory to go back to it's form, when you wash it, if it stretches then your size will not be the same. That's why you need to make a swatch and submit it to the rigors of washing that it will take if it is dry clean only then that's a different story.
1) Steam blocking
2) Washing and blocking!

WillyG's picture

Oh, I learned the hard way about this...I knit my sister a lace beret in Zitron Ecco (100% wool); I gave it to her unblocked. Then, thinking blocking might help it to lay better, I washed it by immersion, and it has never been the same. After the fact I found out that this yarn tends to grow when washed. Lucky for me, I found almost an identical hat sold in the mall...the color was just not as good.