Table Saw Incident
A quick note on safety: It is very important! Woodworking is not the safest thing to do all day everyday. In just about every step of the construction process there is a chance to smash, cut, slice, and grind your fingers. I plan on building custom furniture for a very long time, and I plan on dying with all ten fingers intact.
The reason I mention the safety thing is because we had a bit of a scare at work today.
Sometimes wood does weird things when you cut into it. While cutting a board today, the cut-off side began curving back into the saw blade – essentially sandwiching the blade between the two pieces of board! The blade whined under the increased pressure, the wood smoked as the friction built up, and my mind raced wildly as I tried not to panic.
It is amazing how fast your mind can think when it is stressed. In a split second I had three distinct thoughts:
1. I scolded myself for being so careless. The table saw is an incredibly useful tool for cutting wood. It is also an incredibly useful tool for throwing wood around and for slicing flesh.
2. I felt the blade heat up, saw it wobble, saw smoke as the friction increased, and wondered how the heck I was going to extricate myself from the mess I was in.
3. I vowed to install two safety features as soon as this ordeal was over.
I knew that I couldn’t let go of the board for fear that the blade would catch it, bounce it up, and send wood and metal flying everywhere, but I needed to turn the saw OFF! I held the board as steadily as possible and yelled to a coworker to turn it off, which he was able to do.
Once the blade had stopped, I thanked God for not teaching me a lesson the hard way, and assessed the damage. The blade was scalding hot from the friction, dull as a butter knife, and probably too warped to be used again. The board sported some fancy burn marks.
As noted above, I decided after this little scare, that it was time to install a few safety features on our 30+ year-old table saw. The first and, in many woodworker’s opinions, the most critical safety feature on a table saw is the riving knife. A riving knife is a piece of metal, the same thickness as the blade, that sits directly behind the blade. It prevents the material that is passing through the blade from clamping down on the blade itself (as happened to me). The riving knife ends up being the thing that gets squeezed if a board was to tweak during cutting, and this allows the blade to continue spinning away unimpeded.
This is the homemade riving knife I had made for our Rockwell Unisaw. I was unable to located the original owners manual anywhere in the office or the shop, but found a digital copy of the original owners manual for this saw on OWWM.com and discovered that this saw originally came with a riving knife! Unfortunately for me, it was probably lost somewhere along the way. I called a local tool retailer and asked them if they could order me a replacement one. The guy on the other line said he could but it was going to cost me about half as much as a brand new saw: $500! Instead I walked to the machine shop next door and asked them if they could help me out and one hour later I had a homemade riving knife in my hand, cut from scrap steel, costing a total of $0!
Here is a picture of the installed riving knife.
Here is a shot of what it looks like while a board is being cut. The riving knife prevents the board from clamping down on the blade, thus preventing kickback and injury.
The second safety feature I installed, or more appropriately, had installed for me, was an emergency off button for the table saw. Many woodworkers hang a board down in front of the on/off buttons that, when kicked, hits the off button and turns the saw off. I didn’t like that (it seemed like it would come with it’s own safety risks), so I had an electrician install a large round button close to the ground that is easily kicked if the user needs to shut of the saw for any reason.
From now on things should be a bit safer around here!
September 21st, 2008 at 8:02 pm
Hi,
I found your blog, and I have a question for you. My boyfriend just had a terribly injury on Friday, is still in the hospital on Sunday. He had some fingers hit the blade, and almost lost a finger. Do you know anyone that has been through reattachment and aftermath? I just was wondering what to expect, since I’m the one to take care of him. Everything is so up in the air right now. Thanks, and thanks for your blog.
kim
September 25th, 2008 at 3:16 pm
Hello Kim,
Fortunately I have not had any severe injuries involving my body and a power tool, just a few close calls, so I do not have any knowledge about the aftermath of a serious injury and issues associated with reattachment. But I did post your question up on two woodworking forums and I hope someone out there will be able to give you some answers.
Good luck with everything.
Jared
Here are the two links to the forums:
http://thewoodwhisperer.com/townsquare/index.php?topic=468.0
http://lumberjocks.com/topics/4793
December 15th, 2008 at 9:28 pm
I also have an older saw like yours and would like to find out more information about the dimensions and what it is made of. Also can the shop remake one for me and how much. I am new to woodworking and have had problems when using my table saw. This should help
Thanks
Don
March 2nd, 2010 at 4:43 pm
Hi,
Found your blog while I was looking for something else. Quite a scary story.
I am guessing that the saw never had a splitter of any kind on it. What surprised me was that an older saw like yours actually came with a riving knife from the factory.
I thought they were more or less a recent addition to saws in North America.
June 1st, 2010 at 12:01 pm
@Kim – hopefully, things turned out well for him.
One word “SawStop”. Look it up.
Some of the unisaw actually came with guards mounted on splitter, and paws. The bolts protruded out the back. Its a fixed guard that only pivots, but doesn’t go up and down with the blade. Not like a riving knife. The main advantage is that with a riving knife, it always remains close to the blade, and doesn’t give any opportunity for binding from the beginning onwards.
August 11th, 2010 at 4:48 pm
Hi Jared- I have just discovered your blog this afternoon, and have spent the past 2 hours pouring over it! GREAT STUFF!
As for the table saw safety features, I have a question- you described the idea of hanging a board, essentially to increase the “target” size of the Off switch. You also mentioned that you don’t like this idea. What is it that you don’t like about it? Just personal preferance, or do you feel it is unsafe in some way?
Thanks!
August 16th, 2010 at 11:45 am
Simon,
I don’t really like the idea of a hanging board because I just feel like it would always be in the way, running the risk of accidentally being knocked and turning the saw off.
Instead, we had a large emergency “OFF” button installed at the bottom of the saw, just above the floor. In an emergency, one could kick the button with their toe and turn the saw off, while keeping two hands on the work piece.
Jared
November 24th, 2010 at 2:53 am
I did sever a finger went through reattachment with little success. it has caused me to look into a guard to cover the blade in such a way to not block alignment and view of the blade and came up with an idea. what if at the top of the knife a thin arm came over the teeth only of the blade, the same thickness as the blade with a leading ramped edge to cause it to raise when stock was fed into it. it would protect your fingers from the business part of the blade and because it lines directly up with the blade would not be in the way of lining up your material to be cut. people take guards off because they are often built in such a way as that makes them awkward to use and in some cases impossible