Friday, September 02, 2011

The "anonymice" want to chew on the notebooks.

None of this was about science.  It was about technology.  This is the kind of technical development that most companies do, and which they keep private as trade secrets.  Go to your cell phone company, and ask to see the data on how they developed their last model.  Then, see what kind of a reception you get.  I am a nice guy. :  )

Just as the proof of the pudding is in the eating, the proof of the knitting is in the wearing. No pile of numbers can inform you as to just how warm a hand knit garment can be. The only thing that can give you the gut feeling of how warm a hand knit garment can be is to wear an ordinary knit garment in the rain until you are cold, (and I mean the kind of cold that hurts,) then while still in that cold rain, then put on a good tightly knit gansey. In a few minutes, you will understand just how warm hand knit wool can be. Numbers cannot tell you this. However, it is easy to make your own samples to touch and feel.

You can prove the effects with some cheapo metal #1 DPN and some tightly spun gansey yarn or MacAuslands. You whittle/drill a knitting sheath or stick - crude works - directions are in this blog. Total investment less than $10. Videos of the knitting process are in this blog.

Then, you knit some swatches. Do you like the firmer fabric? - that is all that counts.

Early swatches

I started by knitting tiny swatches, from 800 - 1,000 ypp yarns, very tightly on # 1 circs, and blowing air through them.  Yes, they blocked air flow and thus should be warm, but I did not see any practical way to knit such fabrics. Knitting them with circs was too hard on my wrists. The early data was crap because the fabrics were crap. It only told me that tighter was warmer, and that the relationship was not linear.  As I knit tighter and tighter, suddenly the fabric was much warmer.  The curve relating fabric density to warmth has a sharp bend in it.

 I spent months trying various combinations of long DPN to knit tighter fabrics, and mostly just poked holes in my wife's living room furniture. It was months before I figured out how to use a knitting sheath. Then, the fabrics were much better.

Second Generation Swatches

Blowing air through and pouring water on the Second Generation Swatches gave me the courage to knit some sweaters at those gauges and in those patterns.  The interesting thing to come out the second generation was that some stitch patterns were much warmer than other stitch patterns. This caused me to think incorrectly that the cable patterns were somehow connected with additional warmth.  This was clearly one point where I got things wrong.

I knit the first real gansey from the old Lion Brand Fisherman's Wool.  (The production of this yarn has been moved to China, and it is now very different!)  In those days it was 5 finely spun plies, loosely plied to together.  I knit the sweater on gansey needles with a knitting sheath in about 30 days while I was taking time off to rest my wrists from too much computer work.  This is the warmest garment that I have ever knit.  It is good for skiing on cold days and taking naps in the snow.  It was knit in white, worn and tested, then dyed blue to see if blue sweaters were warmer.  They are.  Note that this is an odd yarn.  You are not going to be able to replicate anything like this gansey because this kind of yarn is simply not available.  On the other hand, this is a very important data point for the hand spinner because it tells us that yarn structure is very important in the warmth of the fabric, and that yarn plies can rearrange themselves within the fabric structure to fill in gaps.  Such rearrangement is not possible with more tightly plied yarns.  Thus, there is more than one way to make a very warm fabric.

The second gansey was knit from MacAusland's three ply (Aran weight). It was knit on #3 steel DPN.  This I call my "gardening gansey" and has been worn until it is going thread bare and no longer has as much warmth as it had that first year.  Then it was worn while I pruned my mother's apple orchard in a week of freezing rain and wind.  The only other guys out that week we the power company's emergency linemen repairing the power lines that kept icing up and blowing down.  I still did not understand how special a tightly knit sweater could be.

One cold rainy day, I put a couple of ordinary fisherman's sweaters that we hand purchased in Canada and the two sweaters that I had knit tightly in my backpack and I went went for a long walk.  I would put on one of the commercial sweaters, and in 15 minutes, I was cold, wet, and freezing.  I would put one of my sweaters on, and in 15 minutes, I was warm, dry and comfortable.  This was an Epiphany! Numbers based on swatches did not hint at the warmth of the entire garment.  These inter-garment comparisons have been done over and over, as they are the only way to get a measure of the truth about how warm a particular garment construction is.

Moreover air flow through the fabric is a minor part of the effect.  The critical point is getting the fabric tight enough to block drops of liquid water.  Fabrics that block the movement of liquid water through the fabric are much warmer than fabrics that do not.  This is true even when it is not raining because the body produces a lot of water vapor that tends to condense on the outer surface of  clothing in cold weather.  Convention knit fabrics are so loose that these droplets tend to be redistributed back toward the skin with any motion of the fabric.  Then the droplets wet the skin or under garments (often linen or cotton, which wicks the water against the skin), the water absorbs its heat of vaporization from the skin (cooling the skin), and the water vapor moves outward through the fabric, condenses on the outer surface of the clothing, and is transported back to the skin again.  Thus, the liters of water released by the body each day can transport huge amounts of heat away from the skin because the water recirculates through the clothing system.

Laying a gansey on a table,  pouring a bottle of water on it, and having no water leak through to the table is more dramatic that any notebook full of numbers.  It says, this sweater is different from any sweater you have ever worn.  There are photographs in this blog of sweaters on the patio, with water on them.  Yes, those sweaters are different from anything that you know.  They are weatherproof.  However, seeing that a sweater is weatherproof  still does not convey how warm the garment is.  One problem is that we do not have words for the "warmth of garments" in common English, and most people do not have experience with the technical units (i.e., R value, suits).

It turns out to be very easy to knit stuff that is way too warm for ordinary use. The only people that need gear that warm are professionals - crab fishermen on the Bering Sea, electrical linemen working during an ice storm, guys installing tire chains, and so forth. Most recreational sailors, hikers, skiers, & bikers do not venture out in really bad weather.

This is hand knitting. A dab of hand lotion changes the tension and hence the warmth of the fabric. Different batches of yarn are blended from different kinds of wool and thus generate different insulation values. Nothing is standard. On the other hand the skill of the knitter allows the production of consistently warm objects.

The vagaries of hand knitting are not big deal if you just want to knit a fabric that is warm enough to keep a sailor warm. You simply test your own materials and knitting technique.  If you knit a garment that fits rather snugly, and you knit it tight enough that you can lay the swatch (or the garment) on the floor, pour a bottle of water on it, and 20 minutes later the floor is still dry, then that (swatch) garment is weatherproof and will keep a sailor warm. Another test is to hold a single layer of the fabric right in front of your eyes as you face a bright window. If you cannot see the outline of the window, then that garment is weatherproof and will keep a sailor warm. Two different tests and they both work.


Anonymous said...

"those sweaters are different from anything that you know. They are weatherproof"

Hey, I sure know them. My first gansey that I knit as a teenager out of eight-ply (from one of the Gladys Thompson patterns) was waterproof also. Good for camping. Not dyed; grey from the sheep. No problems with my hands, but no OA at that age either.

Anonymous said...

P.S. I wonder if that sweater would get warmer if I dyed it (post-knitting)? What do you think? ;) Too bad it's long since returned to dust or it could be subjected to testing by an hapless MSE student.

=Tamar said...

The garment is obviously weatherproof if the water puddles on top of it; what if the water soaks into it, but just doesn't reach the floor?

I had a rainproof sweater once, but I outgrew it and no longer have it. It was nice while it lasted. Oddly, it was also dark indigo blue.

Anonymous said...

Very illuminating post, though perhaps not in the way you intended.

I don't quite understand the hostility in your post about people who "wanted the numbers." I'm one of those "anonymice" who expressed a real (and, I thought, an enthusiastic and friendly interest) in the actual details of your experiments.

First, I don't generally use my name or identifying information on internet sites run by people with whom I am not personally acquainted. If this is unacceptable to you, then we have very different ideas about personal security and safety protocols online. Since this was my profession for a good many years and my success in it allowed me to retire quite young and pursue passions such as knitting, I don't plan on changing my approach.

Second, I find it inconceivable that a "good scientist" (or even a decent technician) would take the time to design equipment and experiments, create samples, conduct hundreds of tests and then NOT collect and tabulate the data. In my world, we like data. We like it so much that we save it, organize it, analyze it, use it to design more experiments and then share the results with like-minded enthusiasts. If you feel that an honest interest in your work is some kind of gauntlet flung at your knitting, may I remind you that YOU were the one who repeatedly talked about your experience in research and your enormous sample set? I had no expectations of seeing those results detailed in a blog post; I simply thought that you had excellent material for a book.

My suggestion for that book was based on my interest in your work and results. Based on your rather inexplicable attitude, my interest has certainly cooled. I came across your blog after a search on Google, read many, many posts, thought I recognized a kindred spirit and was thrilled. Obviously, I was wrong. Best of luck in your continuing work - I shan't be checking in again.

Aaron said...

I did knit a sweater in white, test it, dye it, and test again. Here at 38 N latitude, the blue was warmer during the day. (Just as the physics theory says.) Theory says the blue would not be as warm on a clear cold night. This I have not tested, but it is the kind of physics that is always correct.

AL : )