Tuesday, December 25, 2007

Your steam iron: a mighty weapon in the fight against curling and flipping bands (and why bands want to flip in the first place)

Today TECHknitting has a new use for an electrical appliance you probably already own: a steam iron. A steam iron is a mighty weapon against curling and flipping, so part of this post takes a detour into WHY bands want to flip in the first place. But before all that, a brief look at the iron itself.
 
Steam irons, 101
Steam is vapor from boiled water. In order to make steam, irons boil water inside a little chamber. Water contains minerals. Sometimes, the mineral load of the water is high enough to cause problems. If your kettle stays clean, no worries. But if your kettle is mineral-encrusted, then so will the inside of your iron be. 

A new iron will not give trouble, even if filled with high-mineral-content water. This is because when water turns to steam, it leaves behind its mineral load. But as the inside of the iron's heating chamber becomes coated with minerals, the steam channels get clogged, and the iron starts spitting bits and flakes. Where I live, water is hard from dissolved limestone, so tap water in a steam iron causes whitish powder to spray out with the steam. In other areas, more staining minerals are found in tap water: iron (the metal) dissolved in water causes your iron (the appliance) to stain clothing gray or brown. 

Therefore, keep a new iron new by topping it up only with distilled water--a gallon from the supermarket will usually last quite a while. If no distilled water is handy, then boiled COOLED water is a near substitute. Boil the water, let it cool in the pot, and pour the cooled water off, leaving the mineral sediment behind. DO NOT USE BOILING WATER--first, you will hurt yourself, second, you might wreck the plastic parts of the iron, and third, the water does not shed the minerals until it cools. 

Clean an old iron by using distilled water to steam-iron some old towels on the highest heat setting and the highest steam setting. Run at least three or four refills of water through the iron (this won't take that long--steam irons have tiny reservoirs). If the iron seems to be getting clean, you might trust it on your woollies, but if doubt remains, use a pressing cloth or a flour-sack kitchen towel between the iron and the woollies. (This is also a good idea to prevent scorching, more, below.) 

Another problem with irons is gooey sticky stuff melted onto the sole plates. This happens from ironing plastic-y dust onto clothes, or ironing synthetics on a high setting: plastics melt. The cure is iron cleaner.  Iron the residue off onto rags.

GETTING THE CURL OUT (or at least taming it)
Stockinette curls. Perhaps the most annoying curl happens when stockinette is edged with a non-curling fabric--an edging which is SUPPOSED to stop the problem. Up flip the sweater hems, bands and cuffs, or down they curl, or maybe both. The one thing they don't do is lay flat. 

A tangent on band flipping and curling

Typically, a garment pattern will call for a band of a non-curling fabric to be knitted onto a stockinette fabric. The chain of logic is this: stockinette curls like mad, but that garter stitch (seed stitch, ribbing etc.) does not curl or flip. It seems that adding ribbing would therefore prevent flipping. Logical, but unfortunately, untrue. 

See, the garment edge itself will not curl up. However, the whole garment continues to curl, taking the "non curling edge" right along with it. Curling and flipping is due the stockinette fabric to which the non-curling stitch bands have been attached, not the bands themselves. 

One last note: this post lays out the steam-iron method for dealing with already existing curled edges, like the sweater bands. This NEXT post shows how to knit edges less likely to curl in the first place.

 
Helpers in the fight against curling: CHEMICALS, BLOCKING and STEAM IRONING

Chemicals, blocking and ironing are all common in commercial knitwear.  Think about it: commercial knits lay flat, while hand knits want to curl strongly. Why?  It's partly because machine-made knits are usually knit from finer yarn which exerts less curling force. However, the real answer is industrial processes like giant stentering (steaming/stretching) machines or chemical relaxers. 

Hand knitters facing curling or flipping can use similar tricks. For chemical treatments, fabric relaxer is a good start.  Evidently the relaxer is essentially a wetter, which lets moisture into the fabric fibers, causing them to swell a bit, and de-kink. Once damped with fabric relaxer, the item can be further wetted with a spray bottle of water, or even a quick trip to the sink for a brief soak, and this treatment can be followed by wet-blocking or steam blocking. 

As far as mechanical processes, it is not just industrial knits which are stretched. Hand production knitters of the past traditionally employed extreme blocking. Those picturesque sweater forms ("jumper boards") in old photos from the Shetland Islands had a serious purpose. Of course, extreme blocking like this is not only going to tame curling and flipping, but it is going to make the fabric grow. Commercial knitwear factors this in, but knitting purposely small followed by serious stretching isn't part of the program for most hand knitters--lace shawls being the exception.

And, this is where the steam iron comes in. It is the most mighty weapon against curling and all the other tricks hand knitting gets up to. 

A steam iron in the hand of a knitter is capable of producing three things:
  • steam
  • heat
  • pressure
Each factor has the capacity to alter hand knit fabric, sometimes fatally, so the first rule of using a steam iron on woollies is BE CAREFUL: amp up gradually. 

STEAM
On wool and acrylic, the steam has a great effect all by itself, so be sure that the STEAM setting on your iron is set on "high" right from the start. It may be that steam with hardly any pressure at all will do the trick, as it does on kinked yarn. This is called steam blocking, and if it works, you're all set. In other words, on acrylic and wool, the ideal is to start with a steaming, billowing iron held just above the fabric, and only if this does not work, would you next progress to light dabs, and only then to pressure. If your item is silk, bamboo, cotton--anything but acrylic or wool--do NOT start with billowing steam. Instead, start with the absolutely lowest steam AND the lowest heat AND the least pressure. Increase the steam in the same manner as you increase heat and pressure: in small increments.

For steam blocking alone, make the garment nice and steamy with several passes close above the fabric, but not touching. Then, spread and smooth with your hands (careful of the hot fabric though!) Keep steaming and spreading, steaming and smoothing until the garment looks the way you want and the bands lie flat--or flatter, at any rate. Then, let dry in the smoothed and stretched position. Dry time for steaming is much less than for wet blocking, and a small swatch is ready instantly, but a large garment needs a couple of minutes to cool and set. 

HEAT
Heat has a powerful effect on fabrics. Most obviously, a too-high heat can burn precious hand knits. Even at non-burning temperatures, Heat can "set" woolen fibers--kink them permanently. It can melt acrylics, changing the very composition of the fiber. 

With wool, be careful of scorching--maybe use a pressing cloth or flour sack towel between the garment and the iron. For acrylic (or another synthetic) use the cloth or towel PLUS be careful of melting--increase the heat by VERY slow degrees, and realize that non-wool, non-acrylic fibers are even less resistant to heat. 

 
PRESSURE
All knitting three-dimensional, so ironing can crush it. On stockinette garments with garter or ribbed bands, remember that bands have no tendency to flip. It is the stockinette which acts up. Luckily, stockinette is the flattest knit fabric: less likely to show effects from pressure. If you get as far as actually ironing the fabric, dab lightly on the stockinette part of the fabric only, to avoid crushing the 3-d nature of garter, rib or textures.

 
COMBINATION OF FACTORS
For wool and acrylic, start with a fully steaming iron. Progress in pressure and heat carefully.  For other fabrics, start with minimal steam, and progress in steam, pressure, and heat carefully, increasing each factor, one at a time, in small steps. 

As to the interplay of heat and steam, most irons will give steam on the wool setting, but there are two higher settings, usually: cotton and linen. For hand knits, I can't imagine ever getting above the wool setting for actually touching the fabric with the iron, even with a thick ironing cloth. However, the higher settings do generate more steam. So, if using the cotton or linen setting for the steam effect, turn the iron back down to wool setting and let a cool a little minute before actually touching iron to fabric.
 Steam ironing is a big gun--it certainly has the power to persuade curling stockinette to lie flat and stop flipping. But, there's a trade-off. The more heat, pressure and steam, the limper the fabric. 

I knew a production hand- and machine-knitter who HEAVILY ironed all her garments--and she made many over the years. All those many garments lay flat, yessiree, no question: never a curl, never a flip, no misbehavior at all, and the bands got up to no tricks. However, all those garments were oddly limp, with none of the spring normally associated with knit garments. Bottom line: lots of steam and a light dab or two is the practical upper limit before limpness sets in. 

--TK
* * * 
This post is part 6 of a series. The other posts are:
*How to knit better bands and cuffs, part 1: Opera and Soap Opera (November 1, 2007) 

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