Saw Safely

A wood shop safety compendium.

99.9% is not safe enough. Spend a minute, save a finger.

Disclaimer
Background
Table saws, including choosing featherboards and push blocks
Routers
Angle grinders
Other
Understand design decisions, like UK processes
Injury research
National guidelines
Equipment manuals

Disclaimer

This is not advice, it's just my personal experience. I'm not an expert. What works for me may be useless or even dangerous in someone else's situation.

These are notes that helped one person – me. It's a subset of safety-related topics that you should research and form your own opinion about. Reading this won't replace decades of experience, hands-on training, or a thorough understanding of shop safety, so:

Use these notes at your own risk and at your own discretion. Maybe they fit your situation, maybe they don't.
Read, understand, and follow equipment manuals.
If you don't feel confident, or you haven't used power tools regularly for many years, learn from an expert in person. Knowledge alone should not inspire confidence.

Background

Before anything below was relevant, I did the basics, like:

Learned what causes kickback (raygirling.com) and how to avoid it (woodcraft.com)
Replaced my table saw with a flesh-detecting SawStop to nearly eliminate an entire class of common accidents. As long as a flesh-detecting table saw exists, I have no reason to use a saw without it – and I'd spend the rest of my life thinking about an injury received while using any non-flesh detecting table saw.
Used the SawStop blade guard, riving knife, and kickback pawls (SawStop guard video) for through-cuts.

And meta:

Googled for common accidents with each tool I used, and read firsthand reports from injured woodworkers: accident discussion (canadianwoodworking.com), detailed injury reports (thewoodwhisperer.com).
Ask myself "Am I tired?" throughout the day and adjusting my task to fit the answer.
Learned to ignore anyone who said "Ridiculous! You don't need a <riving knife, blade guard, ear protection, or any other piece of objectively-proven safety equipment>!"

I attribute those comments to sampling bias (most people who take shop risks will never be penalized for doing so), the Dunning-Kruger effect, and/or other people valuing their fingers less than I value mine.

Tired? Stop.

This deserves its own section, or perhaps 11 signs you should stop woodworking for the day. Be careful of #12, "Inability to Stop Working – Compulsively Trying to Finish."

Table saws/saw benches

From Table saw injuries: epidemiology and a proposal for preventive measures:

"Blade contact injuries are by far the most common, representing over 85% of table saw injuries.

…

A nationwide injury survey distributed in a woodworking magazine found that 42% of reported injuries were caused by table saws and that they were the cause of the highest proportion of amputations (39%)."

These injuries are trivially preventable. If I wasn't already using a flesh-detecting table saw, I'd turn off my computer and go buy one. This is no longer an optional piece of equipment, any more than a new syringe is optional for a doctor giving an injection; eventually, given enough use, something will go wrong, and the cost to prevent it is tiny. This is true regardless of experience; if Jimmy DiResta can sever his pinky finger, anyone can.

Riving knife, blade guard, & anti-kickback pawls

With a SawStop, choosing these is basically solved.

For specialty saws which are so unique that no flesh-detecting equivalent exists, look at SharkGuard and Save 'em System.

Shark Guard comparison (sawmillcreek.org, 2010)
Review of riving knives (Fine Woodworking, 2009)
Motivation to replace the saw and adapt the process (finewoodworking.com) to a newer saw; more (lumberjocks.com)

Physical position

Keep Where do I stand at the table saw? in mind when evaluating push block approaches:

Featherboards

A User's Guide to Featherboards (Fine Woodworking, 2006)

FeatherPro

FeatherPro, with a unique kickback-arresting foam hinge (4m28s):

"Dramatically reduce your chance of harm through this hi-tech hinge while maintaining amazing flexibility and feel … If you accidentally hit your blade with this featherboard it won't shatter or explode in your face"

Foam hinge demo:

More example uses on Instagram.

Magswitch

Magswitch workholding system, as shown in a demo video (2m23s) or by Highland Woodworking (8m40s).

Can be used anywhere, regardless of location of miter sled slot
Vertical/fence-mounted and horizontal/table-mounted
Other magnetic supports, like band saw resaw guide

JessEm TS Stock Guide

JessEm Tools makes unique and incredibly effective Stock Guides:

Push sticks/push blocks

Multi-direction push block

Consider a MicroJig Grr-Ripper GR-200/GR-100, Save 'em 3-bearing hold down, or other push block which exerts forces in multiple directions (towards the rip fence, towards the table, and forward through the cut), and contacts the workpiece on both sides of the blade.

For table saw, Grr-Ripper requires removing a blade guard (but not riving knife). As an old version of MicroJig's Web site states, Grr-Ripper is only designed for cuts where a blade guard wouldn't fit regardless:

"With safety as the over riding factor, we aver that the GRR-Ripper® System is not intended to replace or interfere with the saw table blade-guard/splitter combination. It is specifically designed for those times when the conventional combination of a blade-guard and anti-kick back pawls would interfere with the wood working process especially during narrow ripping"

How Grr-Ripper works:

High-friction push block

A push stick like Bench Dog push block or MicroJig Grr-Rip Block can be used with a saw blade guard.

See Bench Dog friction:

See Bench Dog friction (1m13s)
Tradeoffs of Grr-Ripper without a blade guard and Bench Dog push block with a guard.
Using Grr-Ripper for certain rips but not other cuts

Routers

Is it possible to fully shroud the portion of the router that isn't in contact with the workpiece? If not, why not?
Does this cut really need to be done freehand, or can it be done on a table?

Freehand

"Reduce the tendency of your router to tip when routing an edge of a board" with the Fulton Offset Router Base (example use).
Other trim router oversized sub-bases and discussion.

Router table

Cover the bit with a Peachtree bit guard or Woodpecker guard with integrated fulcrum pin and dust port.
Don't hold small parts with bare hands. Consider MLCS small parts holder for clamping small pieces or make a DIY version.

Angle grinders

Watch "You need to know how dangerous this tool is (how it got me)," including a recorded accident that would have been difficult to prevent.

Watch this comparison of grinding wheels, which compares the likelihood of kickback-like events with different types of wheels. Chainsaw-style cutters receive a 1 (least safe) out of 5.

Per Metabo, "Almost a fourth of all accidents with power tools were caused by angle grinders." Considering how infrequently they are used compared to other tools, that should be eye-opening. Consider whether the work can be done with a flexible shaft tool (such as Foredom) or rotary tool (such as Dremel or Ram OZ).

Read some US OSHA injury reports.

Blade material

An article about abrasive and diamond blade material and what happens when the blade shatters. Discussion of it. As the article writes (emphasis added):

"the tool that injures the most people every year goes largely unnoticed by the majority of workers employing it. This instrument of destruction is the angle grinder … Silicon-carbide blades are 6.3 times more likely to end in death than a diamond-blade should they shatter. If it’s not curtains, the chances the injury will be serious enough to require hospitalization is 13 times greater. Opt instead for a diamond blade."

Angle grinder kickback

Metabo "S-Automatic safety clutch" kick back protection "minimises kick-back to the lowest level when the disc jams unexpectedly - for maximum user safety." (more)

Other

Band saw advanced safety techniques
Drill press and drum sander flip-up guard
Sharpen chisels regularly; less required force means less momentum suddenly transferring, ie, less chance of injury. WOOD Magazine, Paul Sellers

Understand design decisions & trade-offs

UK processes vs. US processes

Use the UK as a chance to examine US practices with a critical eye. The UK has different work preferences, electricity voltage, and regulations (like legally requiring a blade guard/crown guard for all cuts on commercial table saws/sawbenches). As a result, woodworkers in the US and the UK perform common operations differently. Introductions:

Short: Why the British think we're crazy
Long: What you don't know about European saws (2007)

Thanks to UKWorkshop, I learned a lot about how UK woodworkers view certain US processes:

Dadoes are generally done with a router or shaper, not a dado set.
Sliding tables are much more common than crosscut sleds. One person's take.
Table saw fences can be moved forwards and backwards. They're generally positioned to stop at the end of the blade, so if a ripped workpiece spreads, the rip fence isn't forcing the wood into the blade.
Attitude toward safety

Unusual products

Save 'em System

Everything Save 'em System makes seems to be innovative. Watch their products (1m49s):

Pro Cut 50

The Toronto Tool Pro Cut 50 (6m14s) is a table saw competitor that's more like a panel saw turned horizontal (or a hand-operated CNC table). Wood position is fixed and saw moves.

"A conventional table saw is prone to "kick back" due to design but the top mounted saw of the Pro-Cut 50 encapsulates your material thus virtually eliminating the possibility of 'kick back'

…

By simply unlocking and removing the saw from the Pro-Cut 50 sled and placing the router in its place, you have instantly converted your Pro-Cut 50 from a precision table saw to a full size precision "X" & "Y" router table"

Retrospectives

Matt Vanderlist critiques his own router accident ("If I had taken the time to break out this guide fence…").

Mr. Fix It critiques his own table saw accident, which would have been far less severe with a flesh-detecting saw.

Injury research & statistics

From Table saw injuries: epidemiology and a proposal for preventive measures (2013, Plastic and Reconstructive Surgery):

"Blade contact injuries are by far the most common, representing over 85% of table saw injuries. … Lacerations were the most frequent injury sustained (66%) but amputations were not uncommon (10%–15% depending on the sample).

…

The saw’s blade guard was in use during 31% of blade contact injuries and was removed 67% of the time; … For injuries occurring without a blade guard, the most common reason for its absence was consumer removal (75%)."

From Survey of Injuries Involving Stationary Saws (2011, US Consumer Product Safety Commission):

"injuries related to table/bench saws account for 78.0 percent of the survey-based estimated total number of 101,900 injuries associated with all stationary saws (i.e., table/bench saws, band saws, radial arm saws, and miter saws).

…

A rip fence was in use at the time of the injury in 85.3 percent of the cases.

…

Overall, the stock kicked back or jumped in 40.5 percent of the cases. In 93.7 percent of the cases in which the stock kicked back or jumped, the operator thought that the blade contact was due to the stock kickback. When the stock kickback caused the injury, the operator’s hand was pulled into the saw in 65.2 percent of the cases."

From Non-occupational Table Saw-Related Injuries Treated in US Emergency Departments, 1990-2007 (2011, Nationwide Children's Hospital):

"In cases when the mechanism of injury was documented, kickback was the most common mechanism (72 percent)"