July 14, 2009
Welcome to Issue #04 of
Wood Shop News
brought to you by:
Wood Shop News
brought to you by:In this issue:
- the history of sandpaper
- work in progress
- new and for sale
- woodworking classes
- on a personal note
- final words
The History of Sandpaper:
Everything You Never Knew You Wanted to Know About Sandpaper
(Thanks to Lisa B from MA for the topic)
Sandpaper, a type of “coated abrasive,” as it is known in the industry, is a flexible backing coated with a layer of cutting material. It is generally used for smoothing, cleaning or roughing a surface. Today the list of materials and applications is impressively long, with most coated abrasives being used in industrial production.
In the beginning it was much simpler.
The earliest mention of “sandpaper” is from 13th Century China. The abrasive was made from crushed shells, seeds or sand, which were then bonded to parchment using natural gum.
Since then other materials have been used ranging from shark skin to flint. Glass was a common abrasive starting as early as the 1700’s. By 1769 glass-paper was being sold on the streets of Paris and people were warned of counterfeit glass-paper made with inferior abrasives.
In 1834, Isaac Fischer Jr of Springfield VT, patented a mechanized process for mass producing sandpaper. Nearly a century later, in 1916, 3M invented wet/dry sandpaper which is used with water as a lubricant to wash away the slurry created by sanding.
By the 20th century sandpaper was replacing glass-paper in the US. A 1935 addition of Home Craftsman Magazine described sandpaper as:
[A]n abrasive material prepared by coating stout paper with glue and sifting fine sand over its surface before the glue sets.
Today sandpaper is still made with garnet as well as aluminum oxide, ceramic and silicon carbide among other abrasives. Each material has its own properties that suit it for a specific task. Technology continues to improve both materials and the process of applying them. As woodworkers we reap the benefit.
Check out my expanded article on
choosing and using sandpaper
for more information on modern abrasives for woodworkers.
New and For Sale
Visit my sale page
for new work and sale items. Custom work is always welcomed.
In Progress
Recently, I took a break from boxes to make a couple Adirondack chairs.
I've always liked the looks of these chairs, as well as their comfort, but I'd never made any before.
I enjoyed the process. It mostly involved cutting out templates and then cutting the pieces on my bandsaw. The joinery was all butt joints and screws, so there wasn't anything particularly difficult about it. Lots of sanding.
Mahogany, cedar, white oak and ipe are all good woods for outdoor use as they resist rot and weather nicely. This pair is made from mahogany.
Fortunately, my dog also approved of the design.
Woodworking Classes
(Located S/SW of Boston) Learn new skills or hone old ones in small group sessions tailored to the individual.
Classes are limited to 3 people and take place in my shop outside Boston. They generally meet once a week for 2-3 hours. The sessions go on as long as students are interested, a few months or a few years.
As students progress, class may become "open shop" time when they work on their projects and I answer questions and give suggestions as things come up. Individual instruction is also available.
Contact me for more information.
Rain
Here in MA, where I live, we’ve had a cold wet spring and summer. Rain has been on my mind. So, I looked into it.
Why does it rain?
Let’s start with clouds.
Clouds can form in several ways (and there are many, many, different types of clouds), but the main event is warm and cold air meeting.
The air around us is full of water vapor (humidity).
When warm and cold air meet, the cold air pushes the warm air up. As the warm air increases in altitude the atmospheric pressure lessens. This cools off the air and therefore, cools the water vapor in the air. This cooling causes the water vapor to condense into liquid water droplets. If enough water condenses it forms a cloud.
Four types of clouds
Cumulus (meaning "heap" or "pile"): flat on the bottom with big billowy tops
* Stratus (meaning "layer"): short and spread across great distances
* Cirrus (meaning "curl of hair"): wispy and thin
* Nimbus (meaning "rain" or "rainy cloud"): likely to bring precipitation
(From how stuff works.)
Inside the cloud those droplets can collect together into a drop that is large enough, and therefore heavy enough, to fall back to earth. This happens most easily if there is something the droplets can cling to, for example dust or soot particles. These particles are called condensation nuclei.
If enough droplets cling to condensation nuclei they can become a single drop that is large enough and therefore heavy enough, to defeat gravity and fall to earth. If the conditions are right that drop will hit the ground as rain.
Rain is defined as precipitation in drops that are 5mm or larger. Drizzle is small rain and virga is rain that evaporates before hitting the ground.
Rain and pollution.
As I was looking around I discovered that pollution plays a role in the amount of rain we get. In some clouds, pollution makes it rain more, and in other types of clouds it makes it rain less.
If you are curious and want to know why, for example, it rains more on the weekends here on the eastern seaboard, this site has interesting (and non-technical) info: live science.
Also check out the noaa website for a technical look at the science behind global warming discussions.
And now let us hope for a clear, sunny day.
Final Words and Errata
I hope you have enjoyed reading this ‘zine. Do you have ideas for future topics? Comments? Feedback? I'd love to hear from you. Just hit reply and tell me what you think.If you know someone who might enjoy this newsletter, please feel free to send it on. If a friend passed this to you and you like what you read, please subscribe by visiting my website wooden-box-maker.com or ktwood.com.