Question about felting in the washing machine

If I understand correctly, you knit or crochet with felting yarn, and then put the finished piece in the washing machine on the wool cycle. Once the cycle is finished, the project is fully felted. Do you need a special detergent for this, or is regular wool detergent enough?
Can you also felt with regular wool? What’s so special about felting yarn?
If the project made with felting yarn is fully felted and you want to wash it again, will it felt even more? Thanks for your answers

Hi Hamster,
For felting, you need pure sheep’s wool. Felting wool is pure sheep’s wool that hasn’t been treated. Sheep’s wool that isn’t specifically intended for felting has been specially treated so it doesn’t felt during washing. (Superwash)
This wool usually felts at higher temperatures—60° and up—but usually not as evenly.
Felting wool felts during wash cycles at 40°.
You can use regular laundry detergent!
If you wash a felted item again, it will continue to felt. The advantage of this is that if the piece is still too large after the first wash, you can wash it again, and the piece will become smaller and more compact.
However, felted items can therefore only be hand-washed or washed at a maximum of 20°.
I hope this helps!
Best regards,
Karin

Even though this is Hamster’s thread, thanks, Karin, for the tips. If you don’t want to felt in the machine, can you also felt by hand?
I think it would be difficult to reach the necessary temperatures when washing by hand, though. Or is there a trick to it?

Hi muetzekatze,
you can also felt by hand, but in that case you’re not felting something that’s been crocheted or knitted—instead, you use felting wool in fleece or skein form and shape it into shoes (around a shoe last or other mold). Then, using hot water and soap, you felt the whole thing by stroking and rubbing it.
But that’s a separate technique—wet felting.
I’ve never heard or read of anyone felting crocheted or knitted items by hand, and I don’t think it would work very well—the washing machine is definitely the more reliable option.
Best regards,
Karin

Thanks, Karin. I saw a video on YouTube where they were felting the strands by hand, so I figured that was the standard method.

You can definitely felt crocheted or knitted items by hand, as Karin already mentioned: provided you’ve used pure wool that isn’t superwash-treated. I tried it last winter. It works very well with lots of wringing and kneading, and by alternately dipping it in hot soapy water and cold water. Of course, it’s more labor-intensive. But you can always check how much it’s been felted so far. For example, you can knit or crochet a scarf and felt it just a little—it’ll shrink a bit and become firmer and cozier :-) Rinse it well and add a tablespoon of vinegar to the final rinse water.

Well, I just thought there had to be other options, since felting as a technique was already common long before washing machines existed.
Thanks for the info, Osaki. What’s the vinegar actually for? Is it to stabilize the color, or does it stop further felting? What kind of vinegar do you use for that?

Hi mützekatze

The vinegar neutralizes the last traces of soapy water and helps against limescale, and neither is good for wool. Regular household vinegar is perfectly fine.

You can’t use vinegar for felting. Every time the wool is washed, you have to wash it gently; otherwise, it will continue to felt until the piece is as hard as a board and the fibers are so dense that nothing works anymore. So always wash it carefully.

Thanks for your info on felting—I’m still a little hesitant to try it. Does it have any effect on the washing machine?