30 January 2023


One-Handed Can Opener

Open cans with one hand

I have had this one-handed can opener for over five years. Though the price seems high for a basic tool, I will say that this can opener has turned the chore of opening cans into an easy and straightforward one. The can opener is easy to attach to the can and then you are away with a one-handed cranking motion (squeezing the handles together) to open the can. I can’t recall a time when I have had to restart the opening process (as is my norm with other can openers). The cranking process takes some effort but it is not enormous — I think that it would be feasible for anyone with minimal hand strength. To note however that this can opener is the classic approach where the lid is cut off leaving sharp edges to deal with.

-- Rell DeShaw 01/30/23

30 January 2023


Tools for Possibilities: issue no. 19

Once a week we’ll send out a page from Cool Tools: A Catalog of Possibilities. The tools might be outdated or obsolete, but the possibilities they inspire are new. Sign up here to get Tools for Possibilities a week early in your inbox.

Flexible epoxy

3M Scotch-Weld 3532

This is as close to “bombproof” as I have found a glue to be. It seems to stick to just about anything, although 3M says it’s for metals and plastics. I have used it for gluing D-rings – and other things – into my whitewater canoes.

The rings have been able to hold me boiling through big rapids, often upside-down. For this application the glue joint needs to be flexible and waterproof…and this stuff hasn’t ever failed me. How it is different from epoxy: Fills gaps. Flexes under stress without giving away. Sticks to smooth plastics like PVC or vinyl. Seems a LOT stronger than epoxies. You’ll have to find this in a specialty store or order it over the web. Shelf life is 1 year. — Fen Sartorius

Mixes up epoxy

3M Scotch-Weld EPX Applicator

I always used to buy epoxy locally in disposable dispensers that are supposed to dispense equal ratios of the components. The dispensers never work that well: one side always starts to move first and then to get a reasonably equal mix I have to mix up a lot more than I need.

The 3M duo-pack adhesives are sold separately from the dispenser. Because the dispenser is not disposable, it can be a decently built tool, like a caulk gun for epoxy.

The way it works is that you slip on the adhesive cartridge. The applicator has a plunger that pushes up the adhesive cartridge. Think caulk gun. The epoxy comes in double tubes like a doubled tube of caulk. When an adhesive has a different mixing ratio the tubes in the cartridge have different diameters. And there is a different plunger that fits in the tube. The supported mixing ratios are 1:1, 1:2 and 1:10 because those are the ratios of adhesives available. When you buy the system you get the first two plungers, but the 1:10 plunger is sold separately as it is used only for DP-8005 and DP-8010, I think. Just like a caulk gun you can, but you need not remove the adhesive cartridge between uses. The gun stays clean. There is no need to clean it. (Unlike a caulk gun, the adhesive doesn’t leak out the back and get on the gun.)

In fact, if you’re not so worried about waste there’s even a further convenience: static mixing nozzles. These nozzles attach to the end of the epoxy tube and do all the mixing for you so that it really works like a caulk gun: what comes out is ready to use, completely mixed epoxy.

But even if you don’t use the somewhat wasteful mixing nozzles you can still use the gun to extrude the correct ratio mix of 3M adhesive products and then hand mix. I have been able to mix up just the amount of epoxy I need when with the old system I would have mixed ten times what I needed. (No exaggeration here.)

I first got this system because I was trying to glue zinc-plated magnets to polyethylene. I tried regular epoxy. It doesn’t stick well to either one of these materials. There are two adhesives that I think are of particular note in the 3M lineup.

The DP-190 (which I have only used a tiny bit) is supposed to stick to everything except the “low surface energy” plastics. I saw that it is recommended for use with the zinc-plated rare earth magnets (by the magnet sellers). The DP-8005 is designed to stick to low surface energy plastics. I got it for my application.

I also got a small mat made out of teflon because nothing is supposed to stick to that. This was great for repairs using epoxy. I repaired something and laid it on the teflon and it peeled right off after it was cured.

According to 3M, epoxy shelf life is less than a couple years, so you don’t want to buy a lifetime supply at any given time. The shelf life of DP-8005 is only 6 months. The shelf life of the Scotch-Weld Two Part Urethane is 1 year. — Adrian M.

McMaster-Carr sells a very similar product much cheaper, half the cost, for $23. It does not use 3M cartridges. I have had good experiences with Lord adhesives that this gun does use. — KK

Best source for magnets

SuperMagnetMan, supermagnetman.net

I have been buying Neodymium Iron Boron (NIB) super magnets for years. Back then, Wondermagnets was the only source for hobbyists and they had quite a have changed. For the past five years, I have been ordering my magnets from “Mr. George the SuperMagnetMan,” unequivocally the best source today. His prices are the best on the net. His selection is vast: no one else has the stock he has or the variations in size of commonly available shapes. This is no exaggeration or hype. He’s got stuff you can’t get anywhere else and is constantly adding new items, like axially- and diametrically-magnetized NIB wedding rings and radially-magnetized ring magnets. He has magnets so large they are dangerous (fortunately he has put videos on YouTube that show you how to safely handle these monsters — with large leather welding gloves and a special wooden wedge and a 2×4!). He also sells magnetic hooks, pyramid shaped magnets, magnetic jewelry, teflon coated magnets, heart, star, and triangle magnets. You can even get powdered magnets that act like iron filings on steroids! You name it he’s got it. Most magnets are N45-N50 grade, the highest strength you can buy.

Some of the products I have ordered are the magnet powders, radially-magnetized ring magnet, various size sphere magnets, conical magnets, large rectangular magnets, cubes, and many others. Shipping charges are reasonable. Service is great. One time I ordered a bunch of stuff and never completely checked what I got. I went to use one of the magnets months later and found out it was the wrong size. He sent me the right size in the mail a few days after I emailed him.

Mr. George seems like a pretty cool dude, too. An electrical engineer, Mr. George develops magnet products himself and caters to other engineers, inventors, and hobbyists. He can have custom magnets made to order. He has also put up a series of educational videos on YouTube and has done a lot of work with kids. He has a saying, something like, “Give a kid a magnet and you have a friend for life.” — Laral

A strong hold on brake fluid

Seal-All Adhesive & Sealant

Like other adhesives, this one can be used on metals, glass, wood and leather, but it is the only household product I have ever used that will withstand constant exposure to gasoline and/or brake fluid. J-B-WELD will work in some cases, but you have to thoroughly clean and dry the surface or it will fail. Seal-All will seal a leak in a master cylinder-reservoir (non-pressure side) even if you apply it over brake fluid that has already wept out onto the surface. I have also used it to seal an old Coleman fuel tank, and also a weeping fuel fitting on the bottom of a gasoline tank on my bike. This stuff is not what I would consider a toolbox item, but I ride my bike far from home on occasion, and this is one of the items I like to keep in the “just-in-case” bag. — Jackie Gregory

Squeezes tubes dry

Tube-Grip Dispensing Plier

This Tube-Grip easily squeeze tubes of adhesive, calk, sealant, etc. with more precision, less waste with better finished results than other methods. Learning curve is short for starting and stopping applications. Tubes are squeezed beginning from the tube’s bottom seam, and 96% use of product efficiency is claimed. Very thrifty.

Mechanical advantage is claimed to be ten times more than by hand whether gripping vs. pinching. Less fatigue, more control. Concentration on product flow is enhanced because less physical effort is used during application. Tube squeezers for toothpaste and art paint are a different category. Some calling projects are too small for standard tubes of calk, or are in confined areas where a large gun won’t fit.

Tent seam sealing with drippy sealer is controlled better with whole arm movements and a hand grip vs. finger squeezing. I’ve used this 2” dispensing plier for at least 5-years and would not consider many squeeze tube projects without it. A 2 1/2” model also exists. — David McKenzie


29 January 2023

Chip War/40 useful concepts/Wikenigma

Recomendo - Issue #342

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Who controls computers?

For the past half century the most powerful resource in the world has been computers. The book Chip War is the story of the political, commercial, and military struggle to control this global resource in the form of tiny silicon chips used in everything. Chip War is a brisk, insightful, punchy, fast read. The ups, downs, upsets, rebounds, and flameouts of the major players make it clear that this story is not done and there will be more surprises around this power in the future. Highly recommended. — KK

40 useful concepts

“Principle Of Humanity: Every single person is exactly what you would be if you were them. This includes your political opponents. So instead of dismissing them as evil or stupid, maybe seek to understand the circumstances that led them to their conclusions.” Read 39 other useful concepts in this issue of The Prism. — MF

Encyclopedia of the unknowns

Wikenigma is the wikipedia of unanswered questions and gaps in human knowledge for the curious-minded. For example, words of unknown origin, the dilemma of free will, or the purpose of the human chin. It’s a jumping-off point for the imagination. — CD

Video summarizer

We’ve recommended a site that summarizes YouTube videos before, but Eightify is markedly superior and very cool. This Chrome browser extension gives you a little button on the YouTube video play page. You click “Summarize” and in a few seconds the Eightify AI gives you a very usable text summary of the video content broken into ten parts with time stamps. You can click on the time stamps to play that part. You get three free summaries per week, or you can pay for more (which I have done) at about 30 cents a piece. I use it as a way to quickly get to the most important parts of any video. — KK

Tips to improve your memory

This article has some unexpected tips on how to work on improving your memory, like assigning vivid images to things you want to remember and spending 5 minutes before bed reflecting on what happened throughout the day. The one I swear to do more of is to take more pictures on my phone and actually go back and look at them. — CD

21 mind traps

A 20-minute video that looks at 21 kinds of thinking errors. Here’s an example of the Gambler’s Fallacy: “A University of Chicago review found asylum judges were 19% less likely to approve an asylum seeker if they had just approved the previous two. The same person applying for a loan was more likely to get approved for a loan if the previous two applicants were rejected and was more likely to be rejected if the previous two applications were approved.” — MF

Kevin Kelly, Mark Frauenfelder, Claudia Dawson


27 January 2023


Portable Travel Bidet

Better than wiping

Maybe not the tool that you want to talk about, but like a lot of tools when you need it, you really need it. I had surgery on my “wiping hand,” and my off hand was wrecked years ago from a sports injury.

Knowing that I would be out of commission for at least a month, I found that the portable bidet was a pretty good solution. Easy to use lefty, able to use with warm water, and it did the job. Inexpensive and didn’t need to change any plumbing. Useful for other problems as they might occur “down there.” As they like to say discrete and easy to pack.

Uses common AA batteries that seem to have a long life. 

-- Lee J Ellman 01/27/23

27 January 2023

Kern Kelly, STEAM Teacher

Show and Tell #350: Kern Kelly

Starting his teaching career in New Zealand, Kern Kelley is the STEAM Teacher at RSU 19 in central Maine. He has provided support to educators for over two decades and has conducted professional development events across the globe. He advises a student produced technology support show for the Maine Dept. of Education found at SLAMShow.org. He has brought his student presenters, the MLTI Student Leadership Ambassadors of Maine to numerous conferences around and authored the Google Apps Guidebook.

0:00 – Intro
1:56 – Nomatic traveler backpack
5:32 – Budi USB adapter
8:35 – Root iRobot coding tool
13:20 – Flashforge Finder 3 3D printer
22:04 – Student Leadership Ambassadors of Maine

To sign up to be a guest on the show, please fill out this form.


26 January 2023


Adjustable Book Stand 

Elevates books and tablets

Why would you need a bookstand? Maybe you’ve got a lot to read, study, or reference from, reading a text or tablet, and you’re starting to suffer from neck and back aches due to poor posture; you want to increase your reading speed*; you want something to hold your cookbook off the counter and open while you work on a new recipe; you want to hold a reference open while you refer to it or make notes, without the book occupying your workspace.

Bookstands can come in very handy, but many have drawbacks: it’s hard to turn the pages quickly, it’s fussy to adjust, it doesn’t lift the book off the workspace, etc.

This one is the closest I’ve found to perfect. It holds the book securely, makes it easy to adjust the angle and height, and you can either turn pages rapidly by tucking them under the “arch” of the page clip, or securely by placing the clip firmly on the page.

It works well for speed-reading and studying, note-taking and reference, holds the cookbook off your counter while cooking, can hold musical scores on a tabletop while you practice an instrument, or can be used to display an art book. There are friction pads on the bottom, so you can use it on a lap desk or other not-entirely-level surface without having it slide around.

It also holds lightweight tablets or laptops…but don’t exceed the recommended 4.4 pound weight maximum, or it may become unstable: I can put my iPad Pro on it no problem, but trying to put my 16″ MacBook Pro on it would be a bad idea.

The stand has a clean, modern design; it’s lightweight but very sturdy, with aluminum base and arms and an acrylic support plate (which also has a little gray friction pad to keep electronic tablets from scooting around when you use them). When folded, it’s a little over 2 inches thick. A wrench to adjust the arm tension (which you might need to do if you put relatively heavy objects on it), is included in the box. Test the tension and make sure the unit is stable when you’re using it with heavy or expensive objects.

I’ve added one of those inexpensive clip-on USB rechargeable dual-head reading lights to mine; that way any lack of ambient light doesn’t impede my reading. I’m finding it a lot handier than I anticipated; you might, too!

*P.S: for those interested, I can recommend a classic book, Breakthrough Rapid Reading by Peter Kump, as a very effective and inexpensive self-guided course in speed reading. I’m reading 5 times faster so far, and haven’t made it through the whole course yet… 

-- Barbara Dace 01/26/23


img 01/25/23

Fossil 5e Smartwatch

Ultimate Smartwatch for Fitness and Functionality

img 01/24/23

Biolite 330 Headlamp

330 Lumen No-Bounce Rechargeable Head Light

img 01/23/23


A better file search tool

img 01/23/23

Backyard Birds

Tools for Possibilities: issue no. 18

See all the reviews


img 07/28/17

Ortlieb Dry Bags

Heavy-duty waterproof bags

img 06/28/06

Nolo Self-help Law Books

Do-it-yourself legal aid

img 08/15/12


Direct line to a warm body

img 10/23/06

Animated Knots

Best knot teacher

img 03/15/10

Corrective Swim Goggles

Cheap underwater clarity

See all the favorites



Show and Tell #350: Kern Kelly

Picks and shownotes

Show and Tell #349: Stephen Kennedy

Picks and shownotes

Show and Tell #348: Joshua Schachter

Picks and shownotes

11 January 2023


Cool Tools is a web site which recommends the best/cheapest tools available. Tools are defined broadly as anything that can be useful. This includes hand tools, machines, books, software, gadgets, websites, maps, and even ideas. All reviews are positive raves written by real users. We don’t bother with negative reviews because our intent is to only offer the best.

One new tool is posted each weekday. Cool Tools does NOT sell anything. The site provides prices and convenient sources for readers to purchase items.

When Amazon.com is listed as a source (which it often is because of its prices and convenience) Cool Tools receives a fractional fee from Amazon if items are purchased at Amazon on that visit. Cool Tools also earns revenue from Google ads, although we have no foreknowledge nor much control of which ads will appear.

We recently posted a short history of Cool Tools which included current stats as of April 2008. This explains both the genesis of this site, and the tools we use to operate it.

13632766_602152159944472_101382480_oKevin Kelly started Cool Tools in 2000 as an email list, then as a blog since 2003. He edited all reviews through 2006. He writes the occasional review, oversees the design and editorial direction of this site, and made a book version of Cool Tools. If you have a question about the website in general his email is kk {at} kk.org.

13918651_603790483113973_1799207977_oMark Frauenfelder edits Cool Tools and develops editorial projects for Cool Tools Lab, LLC. If you’d like to submit a review, email him at editor {at} cool-tools.org (or use the Submit a Tool form).

13898183_602421513250870_1391167760_oClaudia Dawson runs the Cool Tool website, posting items daily, maintaining software, measuring analytics, managing ads, and in general keeping the site alive. If you have a concern about the operation or status of this site contact her email is claudia {at} cool-tools.org.

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