A Journey thru the Kingdom of Lint

(Last Updated On: January 22, 2017)

Lint - Ductsmart brush systemLint is everywhere in the modern home. Here is my recent journey through the natural home of lint, the clothes dryer in our basement and its associated ducts, a place that might be called the Kingdom of Lint. Along the way, a little science, plus three Digressions that illustrate the educational and practical aspects of lint.

This blog is longer than my average. It’s meant to be a relaxed read, with a few useful points and a large amount of personal history.

Lint, Linen and Flax

To understand where lint comes from and why some clothing leaves more lint than others, it helps to look at the word itself. Its origins lead us through the process of fabric-making and a better understanding of lint.

The word lint is related to linseed and linen. The word linen is directly descended from the Latin word for the flax plant, linum, which in turn derives from the earlier Greek word λινόν (linón).

The flax plant, also known as linseed, has long been used to produce clothing. The Dzudzuana Cave in the country of Georgia has yielded flax fibers that had been dyed, twisted and spun, apparently to make clothing more than 30,000 years ago.

When flax plants are used to make linen fabric, they pass through many steps. After harvesting, the plants are dried and then threshed to remove the seeds, which may be used as food or in traditional folk medicines. The flax is then treated by “retting,” a bacterial or chemical process that loosens the fibers from the stalk.

Next, the flax must be “dressed” to yield its fibers. The flax is broken into short pieces, “scutched” by cutting or crushing, then a heckling comb is used to pull the fibers away from the woody plant material. The fibers from flax range in length from 1 to 6 inches (25 to 150 mm). The longest fibers are used to weave linen; the shorter fibers may be used to make lower-quality fabrics.

Origins of Lint

The word lint (or lynt) was used in 14th century Middle English as a name for the flax plant. Dressing flax was also referred to linting. Today, if you encounter someone with the surname Lint, it is likely that one of their ancestors worked as a flax dresser, a linen weaver or a linen merchant.

Most fabrics are woven from a mixture of long and short fibers. Today, we use the word lint to describe the short plant fibers. Lint is shed by clothing as it is worn, washed and dried. And since the loss of lint removes material from the fabric, lint-producing fabrics also tend not last as long as non-linty materials.

We all know that some fabrics tend to produce less lint than others. If you have a linen shirt, which is woven of the longest flax fibers, it will not generate a lot of lint. The same is true of pima or Egyptian cotton, which is valued for having relatively long (1.5 to 2.5 inches, 35 to 60 mm) fibers. In general, fabrics with long fiber lengths such as silk, nylon and polyester shed less lint.

Digression #1: While researching this article I encountered a fascinating online discussion as to why men collect more lint in their navels than women do. The bloggers came to no clear conclusion. However, I have my own theory. Women often wear non-linty fabrics such as nylon and silk next to their skin, whereas men wear more lint-producing garments; moreover, men tend to have larger navels, so there’s a more capacious storage area for random lint. Show me a man who always wears linen or silk shirts and (I predict) I will show you a man who collects little or no navel lint. (Of course, that might also be the sort of man who allows no hair to decorate his midsection; some believe that hair removal alone is enough to banish navel lint.)

Hazards of Lint

Lint is generally counted as undesirable and a good reason to get out the vacuum cleaner, but lint is also hazardous in several ways:

Health. Lint and other indoor pollutants may trigger allergies and symptoms of asthma.

Manufacturing Quality. Cleanrooms are controlled spaces used for manufacturing and research in situations where small particulate matter might disrupt the activity. Cleanrooms typically circulate their air through HEPA (high-efficiency particulate arresting) filters, and cleanroom employees wear “bunny suits” of synthetic materials that do not shed lint.

Fire Danger. Lint poses another kind of hazard in that it is highly flammable, so much so that it has sometimes been used to start fires.

Lint for Education

Digression #2. When Nola’s two daughters were young, they were members of Camp Fire (known at that time as Camp Fire Girls). The Camp Fire members who were second- to sixth-graders were known as Blue Birds. As a volunteer troop leader, Nola and a few other mothers helped their Blue Birds discover many things about the world, for which the girls would be awarded badges in the form of beads.

One of the Blue Bird projects involved lint. Each girl acquired an empty cardboard egg carton and used it to collect clothes dryer lint until each of the egg cavities was filled. For a home with young children and frequent clothes washing, it might take only a month to accumulate that much lint.

Then the group of Blue Birds inserted a wick into each egg pocket and poured melted wax into the pockets, enough to congeal the lint and hold it in place. This produced a set of fire starters that might be used to start a camp fire or a fire in the home fireplace. You would break off one or two egg cups, arrange the firewood over them and set them on fire to get the fire going.

Thus a single collaborative activity using lint combined education (lint is a fire hazard!) with practical manufacture of a useful item (an inexpensive substitute for the popular Duraflame firelog).

The Blue Bird experience was an education to me as well. Based on their project, it occurred to me that the present approach in our home, where we store dryer lint in a covered plastic bin prior to disposal, might be really risky!

Constipation in Clothes Dryer Exhaust Ducts

Within our home, the principal collectors of lint are the clothes dryer lint filter, the vacuum cleaner bag, and the areas of floor under the furniture that our vacuum cleaner can’t quite reach. Of these, the mother lode, the easily accessed treasure chest, is the clothes dryer filter.

The filter is supposed to intercept all clothes lint so that only clean air is blown down the exhaust duct and delivered to the outside world. However, some lint can creep through or around the best-maintained filter. Ideally, it is blown outdoors, but it’s possible for lint to stick to the walls of the duct, just as plaque sticks to the walls of our arteries. And just like our arteries, over time that residue can build up and obstruct the air flow.

How likely is that your duct will dangerously block with lint? The people who sell duct cleaning services would like you to toss in your bed, losing sleep until you finally in desperation phone 1-800-CLEAN-MY-PIPES. But this just speaks to the power of advertising to incite fear.

Homeowners who love their leaf blowers have a preferred solution: to blow the lint out with a gigantic burst of compressed air. No doubt this approach is satisfactory in some cases. However, I note that plumbers do not open a blocked drain pipe with an immense overpressure of water, nor do cardiologists unplug your arteries with a pressurized burst of blood.

Therefore it seemed to me that a sensible approach might be to snake a brush through the exhaust duct, pushing out the lint and leaving a clean duct with minimal stress on the duct itself. This is the classic Roto Rooter approach for plumbing and is analogous to some atherectomy tools such as the rotablator, used to cut plaque out of arteries.

My Venture Into the Kingdom of Lint

Our ancient clothes dryer recently went to its reward and we were ready to acquire a new one. While buying the dryer I resolved to use this occasion to clean the lint from our exhaust duct. Fortunately, we did not have a flimsy fabric duct, or an accordion duct whose crevices might serve as nucleation sites for gigantic lint balls.

Our dryer duct consists of sixteen feet of four-inch-diameter lightweight aluminum ducting. It had not been cleaned or even examined since contractor Todd Wire installed it several years ago. The ductwork is shown below in our Grosse Pointe basement.

Lint - dryer ductwork

There is a right-angle fitting on the back of the dryer from which the duct rises about seven feet to the ceiling. Another right angle, and it wanders an additional nine feet around a corner and then attaches to the outside exhaust. The exhaust cover was installed in place of a glass brick and is closed with flaps that open when the dryer air is blowing:

Lint - dryer vent

Tools for the Lint Journey

Next, I needed a proper set of equipment. A search for “dryer duct cleaner” on Amazon.com yields a paltry 352 hits. Further examination disqualified many because they were designed for perfectly straight ductwork. Most others failed to qualify because they could not reach into ducts more than 10 or at most 12 feet.

The only viable options appeared to be Rutland (20 foot cable, $22.73, reviewer score 2.5 out of 5) and Ductsmart (25 foot cable plus storage drum and many accessories, $49.95, reviewer score 4.5 out of 5). Although not every Ductsmart review was positive, in totality it blew away the competition and I bought that kit.

I was immediately impressed by the packaging. The Ductsmart comes in a cardboard box about one foot on each side, with an integral handle:

Lint - Ductsmart box

This type of box is ideal for rarely used toolkits: the top can be readily re-closed for storage and transport:

Lint - Ductsmart packaging

The other equipment I have that is similarly packaged (a comb binding machine and a photographic lighting kit) is easy to use and doesn’t add to clutter.

Inside the box is a Styrofoam tray with compartments for the accessories, beneath which is the plastic drum that feeds out the metal cable.

Lint - Ductsmart kit unpacked

The tray contained a wider range of tools than I ever expect to use: circular wire brushes in three diameters (2, 3.5 and 5 inches); a bullet-shaped fitting to feed through narrow hoses; an auger screw attachment like a drain cleaner; a cranking handle for the cable drum; and various small parts including three small hex keys. Some of this bounty is shown below:

Lint - Ductsmart small parts

There was also a carrying strap and an instruction manual. I felt well equipped to venture into the jungle.

Entering the Forbidden Kingdom

I chose a snow-free day since much of my work would be outdoors. The exhaust duct is a closed space, trapped by the clothes dryer at one end and the exit flapper at the other.

The duct came off the clothes dryer with the loosening of a screw holding a metal band around it. I removed the L-bend from the dryer and then took the L off the end of the duct. Thus I had a straight line of vertical ducting for the first seven feet.

At the outside end, I removed the screws holding on the flapper cover and found the open duct end floating there behind it. It may have been attached to the cover at one time, but now it was just floating in space, unsteadily. I could see into the basement around it.

My plan was to feed the cable into the duct from the outside, pushing the brush ahead of it until it came out behind the dryer. Then I would pull it back out, dragging lint off the walls as it came. The cable drum has a hex fitting allowing it to be spun using a power drill; however, I intended to turn the cable only manually, using the handle provided.

In any case, there was no point in turning the cable very strongly when pushing the brush through the duct: the cable is much smaller in diameter than the duct; exerting too much torque would simply wind the cable into a spring that pressed against the duct walls, preventing further progress into the duct. It was only on withdrawal from the duct that the cable and brush could be spun with any force.

I started by attaching the 2 inch brush. The close-up below shows the brush along with the supplied Allen wrenches that tighten the parts into position.

Lint - Ductsmart brush installation

I noted with approval that all the parts were solid metal – the only plastic elements were the cable drum and its handle, and those seemed sturdy enough for the job. Once assembled, the device looked like this:

Lint - ready to clean!

I soon found that I needed four hands. I was holding the loose end of the duct with my gloved left hand and feeding the brush and cable into it with my right hand. However, the cable drum was so light weight that it wanted to walk around and not stay in position to feed me the cable. I finally fetched a stool to sit on and trapped the cable drum between my feet.

Through Darkest Ductwork with Stanley and Livingstone

The next problem of course was negotiating the brush through the twists and turns of the ductwork. The turns were no more than 45 degrees for the first nine feet but when I reached the right angle turn immediately above the dryer I was brought to a stop. No amount of wiggling, pushing and twisting of the cable would persuade the brush to pop around that corner. This taught me to henceforth insist that exhaust ducting be installed with no more than gentle changes of direction!

Of course I still had the option to enter the duct from the dryer end, so I figured that nine-sixteenths wasn’t too bad. I hooked the duct to the dryer and had Nola run the dryer while I pulled the brush back from outside. I was rewarded with a large bolus of lint, so large that it surprised me, since we clean the lint filter every time we use the dryer. If the lint had been cat hair, you could have made a cat out of the quantity that I had.

It was time to head indoors to clean the vertical section of ductwork. I then discovered a problem at the ninety degree turn. The duct looked solid enough, but the turn was made up of several tapered cylinders that snapped together. The duct was solid only until you started lifting it to get access to the opening, whereupon it sprung apart into its component pieces.

This caused me some chagrin, which was offset by the realization that we now could easily clean the vertical section since it was disconnected from the whole system. It was a quick matter to run the 5 inch brush through it and back, cleaning out yet more lint that was stuck to its walls.

I then returned to the outdoors and ran the larger brush through the duct up to the truncated corner, bringing back only a small amount of lint on its return trip.

Re-Assembling Humpty Dumpty

It is axiomatic that young children of a certain mechanical bent like to take things apart. Those who are able to put them together again are destined to be researchers, or engineers, or surgeons, or plumbers. Those who fail to re-assemble them are more likely to become theoretical physicists like yours truly.

What I am saying is that I am not your all-purpose household handyman. I have learned many things in the course of (paying for the) building and maintenance of three houses, and I have an obsessive-compulsive’s collection of tools, so I am not totally incompetent at manual work. When confronted with a set of disconnected pieces that absolutely must be put back together, I always feel a “glunk” in the back of my throat. However, I shoulder forward.

By this time I had clean ductwork and was able to release Nola from her spousal assistance. She was getting pretty chilly with the cold air blowing through the open duct cover anyway. So I worked on re-assembling the dratted pipe.

I was able to snap the corner elements in place all right, but when I tried to then mount the duct to the back of the drier, things slipped enough that all the parts came asunder again.

The obvious solution to all duct problems is duct tape, and I had plenty of duct tape. However, quick examination of the ducts revealed that they were held together with what appeared to be aluminum tape. This was completely different from my supply of cloth duct tape, and the reason why was evident: dryer ducts get hot, and cloth is flammable.

No matter how many tools and supplies I accumulate, a home project usually involves a trip to the hardware store. Our reliable Pointe Hardware supplied me with a generous thirty yards of aluminum duct tape for under three dollars.

Lint - aluminum duct tape

They also confirmed that aluminum tape is required by building code for clothes dryers; and by seeing their samples of duct exit covers I realized that my ducting was supposed to fit tightly over the flange on the back of my flapper cover.

The rest of the job was a snap. I fitted the exit duct to the exit cover and held it in place with aluminum tape. I assembled the ninety degree fitting and wrapped each joint securely with the tape. I re-joined the middle of the vertical duct, which had come apart during my coming and going. I re-attached the duct to the dryer, finally putting Humpty back on his proverbial wall.

Of course, lint had spilled out everywhere. Globs went into a kitchen trash bag, more was swept and vacuumed up, and my thoroughly linty jeans went into the wash basket. Thus ended my journey through the Kingdom of Lint.

The Bottom Line of Lint Banishment

Later, relaxing with my sweetie at the cocktail hour, I had time to reflect on our afternoon of experimental work. I concluded that the time had been well spent. I felt educated in new dimensions of duct taping and roto-rootering; I felt reassured that our laundry system was breathing safely through clean pipes; I had acquired a practical skill that I may have occasion to employ again, if not on my ductwork then on that of a family member; and I had amassed yet another hopelessly specialized yet useful addition to my obsessive collection of tools and supplies. Nola’s enthusiasm for the project was more measured, but she was a good sport about it and gave me excellent help. I did not attempt to probe her feelings about participating in a dirty and chilly afternoon’s project; not being one to go looking for trouble, it seems to me best not to question a spouse too closely on her opinions about male handiwork.

Would I do it again? Yes, certainly. I admit that the leaf blower approach is glamorous in concept, especially when the video shows how it squirts lint out the dryer vent in a huge cloud that envelops the entire neighborhood. Nevertheless, sometimes it is best to put the hand to the brush.

Digression #3. The special properties of handwork reminds me of the early days of gas lasers, when I as a graduate student worked part-time at Hughes Research Laboratories in Malibu. My supervisor was Bill Bridges and his laboratory research assistant was Bob Hodge.

These early lasers were hollow tubes of quartz that were evacuated and filled with low pressures of various inert gases. The gases were electrically excited, much like neon signs are illuminated. The ends of the laser tubes were covered with polished quartz windows, placed at a precise angle (Brewster’s angle) that was non-reflecting for one polarization of light.

Because the light avoided reflection, light could pass through the end windows with almost no loss. The early lasers had very low optical gain, and low loss optical components were essential to allow them to operate. With the Brewster windows, light could come out of the end of the laser, reflect from a mirror back into the laser tube, and undergo a similar reflection at the other end. When the light built up enough to create laser action, a small amount could be released by introducing a reflector into the optical cavity between the mirrors.

However, this ideal situation required absolutely, perfectly, faultlessly clean windows on the laser. Bob experimented with various solvents that were sprayed on, brushed on, wiped on. He finally determined that no kind of spray gave as perfect a finish as a single wipe of an alcohol-moistened cloth wielded by a (very talented) human hand.

If I seem to distrust the leaf blower’s brute force approach to lint, my feelings stem in part from this early experience in the laser lab. It taught me that less technology and more of a human touch sometimes yields the best result.

I hope you find this lint journey useful, and perhaps even entertaining!

Image Credit: all photos by Art Chester


A Journey thru the Kingdom of Lint — 2 Comments

  1. A very entertaining, educational, and enjoyable read … thanks, Art.

    Your observation about children who like to disassemble mechanical things and their likelihood of entering certain professions later in life struck a bell with me. I would add to your list of professions for the “failures” at the reassembling step, the career of computer scientist. That’s in fact exactly how my own career path went, and for the same reasons as you.

    When I started college at UC Berkeley, I had to choose a major. Not having any idea what I wanted to do with my life at the time, and after discussing the subject with my father (a systems engineer) as well as some professors on a visit to several UC campuses, I decided any career having to do with space travel would work for me (being an ardent science fiction reader all through childhood). The professor I spoke to on my visit to the UC Berkeley campus was in the Engineering field. He told me there was no such major as I had described, but said there were 2-3 courses which had to do with “that kind of thing” in the Mechanical Engineering department, so I could effectively “minor” in a space science field if I took the right courses.

    That sounded good enough for me so I signed up at Berkeley in the college of Engineering, and in the sub-field of Mechanical Engineering. I’m sure many a boy has entered the military after nice-sounding comments of that nature from their military recruiter. And, like many such young men (let’s not call them boys) I quickly found to my dismay that a 4-year stint in mechanical engineering had some drawbacks … like not being able to easily switch to any non-engineering major without sacrificing a number of credits that were accumulated in non-transferrable engineering courses, and having a very restricted choice of courses I could take in addition to those required by engineering itself. This wasn’t going to be the college experience I had imagined.

    That problem was complicated by my not knowing or being told about what you found — that boys who are in the no-reassembly category should NOT choose to be Mechanical Engineers, because .. well .. to be good in engineering you really SHOULD be good at the reassembly part. Life becomes hard for you otherwise, and you will find you don’t particularly enjoy the work you are doing. As with all higher educational experiences, it’s one thing to learn the theory behind things but quite another to put those theories into practice … and while a determined student can succeed at getting degrees (and therefore “succeed” at college) it does not mean they are properly equipped to enjoy the rest of their life doing that thing every day.

    Fortunately, I got lucky (always an available option for those who feel trapped). I took a required computer class in my sophomore year, and suddenly I was in my element .. ducks to water and all that. Knowing a few simple language elements, you could construct a whole world in your mind and then implement it as thought-stuff in a computer, and all it took was perseverance and a bit of creativity to succeed. As a bonus, nothing you constructed would ever degrade, and if a problem occurred there was ALWAYS a solution if you were only stubborn enough. Those happened to match my traits extremely well, so it took only a mid-course life change after graduating from Berkeley to go to UCLA for a Masters in computer science and I was on my way, shedding the mechanical engineering label and happily taking on the mantle of computer scientist. It was only one step from there to ending up at the Research Labs in Malibu, working for one Art Chester (and Dave Rensch) to complete the picture.

    So, for those who have kids or grandkids needing assistance in deciding what they want to do in life, I heartily endorse Art’s perceptive comment about observing how kids handle mechanical reconstruction after their inevitable destruction of mechanical things. If they can put those said things back together again after tearing them down, it indicates one type of career but if they can’t … then they should be pointed at another very different set of careers. They will be much happier and more fulfilled in life if they don’t end up in the wrong category.

    • Charles, thank you for that great personal story! I had no idea that my tongue-in-cheek comment might contain a truth that applied to others besides me. As always, your comments are much appreciated… Art