Thread: Table saw safety

Originally Posted by Mobyturns

Jim, I'm surprised that your apprentices would not be receiving "block" training in the safe operation of power tools and machinery that they would commonly encounter on a "job site."

A table saw is not that common to see on say a house build, but larger builders may well have them back in the shed / workshop or on sites such as shop fit outs or larger sites high rise etc where there is a justification for one.

Dad was a registered builder (chippie) up to the mid 1980's in FNQ and we had a DeWalt radial Arm Docking saw on site. It paid for itself many times over in time savings. He always had a watchful eye on it when he heard it in use.

Kudos for doing the right thing in making sure your apprentices are safe & well trained.

Hi Mobyturns.
My current apprentices (one being my Daughter) are trained by an Rto, not TAFE .
They do power tool safety with the trainer but ultimately their safety on site is up to me.
I contract to residential builders primarily so table saws are rarely seen on site. Generally I use a track saw for ripping anything I need to on site. Apprentices will unlikely need to use the TS for work but I would like to show them how to use one safely.
Cheers Jim

Originally Posted by riverbuilder

A full length fence is not essential, it is downright dangerous. With a correctly fitted riving knife, and a good solid fence of the correct length, you should be able to rip any timber accurately,and safely. If the edge is jointed straight first, ripping to width is a straightforward process, one which I’ve done safely uncountable times in over 40 years.

That hasn’t been my experience at all; although I fully agree with the necessity of having a properly fitted riving knife I can’t see how removing the fence makes it safer. So if my machine has the fence trued to the blade and a riving knife fitted to prevent timber from closing up onto the rear of the blade and I make my cut, by keeping the jointed edge running along the fence the rear of the blade can only brush against the sawn edge. The offcut is of course unsecured and potentially can be ejected back towards the front of the table; but can also fall to the side out of the way. By removing the fence behind the blade what I now find is the jointed edge has less and less area to ride against as the cut progresses. With less bearing area the timber has the opportunity to veer to one side or the other; the riving knife will prevent gross misalignment but whereas before the rear of the blade could only brush against the sawn edge now it has the opportunity to actually bite.

About 14 years ago I was the Chippy in Darwin Naval Base; in the woodshop we had a 24”-ish table saw with no height adjustment so about 10-12” of blade was permanently protruding. It was used to turn 14” x 8” x 3’ baulks of timber into massive wedges for jamming the 200t patrol boats hard into their cradles when lifting them out of the water. The iron fence on that beast was incredibly short; it only reached about halfway between the blade edge and the blade centre. The first time I saw one of the boys trying to carefully pass one of these baulks through it I saw the timber grab the blade and violently judder; fortunately the timber slab was too heavy for it to be thrown back at the user. That saw was immediately quarantined until I added a full-length timber sub fence (the iron fence had drilled holes for a timber facing) which then allowed safer ripping. The next thing I made was a big timber sled that each baulk could fit onto two ways; firstly diagonally to slice it into two wedges and then longitudinally to cut the top off the wedge to about 10”. The timber was fixed to the sled using wedges and handles were fitted so that the saw operator could stand at the side of the machine. I ripped some massive timbers through that saw over the 18m I worked there without any issues, always using the full length fence that I had added.

Originally Posted by Chief Tiff

But do you use the short fence when ripping?

Usually yes especially if ripping 1 or 2 shortish pieces if more or longer pieces then I might take it off.
Ive only removed/replaced it twice this year.

Maybe don't take any notice of me as I don't use a riving knife either - I took it off in 2006.

This is becoming a thread with similar but contradictory responses, partly due to only half the story being told. There certainly is plenty of great info, but there is not an overarching "absolute" set of rules as different tasks, and the engineering design of the table saw and accessories may require a particular approach i.e. fitment / removal of a riving knife; length of fence etc. Dust extraction has a huge influence on procedure and setup.

Generally I do the following, but I will preface my comments in that my saw is a psuedo table / panel saw and has a sliding table with RH blade tilt. It also has an adjustable rip fence, so i can adjust its length across the table to stop short, at blade centre or past blade centre. Much of the following also depends upon how well setup the various components of the table saw are and aligned.

Cross cutting - the rule - use the cross cut / mitre fence & never use the rip fence as a length stop! Well partially true! I do this regularly, however an auxillary stop at least 40 mm wide is clamped to the fence to act as the stop, plus it is fitted well in front of the blade. This gives clearance for the cut piece to clear the blade and not potentially bind / jamb between blade & fence. The design of the table insert also influences my methods, so at times I use a zero clearance insert. Generally the riving knife / splitter design does not affect cross cutting. Always use the blade guard!

Cross Cutting small components - I use custom made sleds to hold the stock and work piece using toggle clamps and also use sacrificial stock to hold them if required. Riving knife / splitter design may require removal for some tasks when using sleds. Some sleds attach to the sliding table, other simple sleds guide / align along the rip fence.

My larger and smaller sleds generally require the removal of the riving knife / blade guard, however I always use a custom blade guard constructed from 12 or 16 mm MDF to cover the exposed blade and use a limiting stop to prevent the blade exiting the rear of the larger sleds. I have a custom 6 mm "Plexiglass" blade guard that covers the entire blade when using smaller sleds that guide along the rip fence (cutting Celtic knots) as the sled and work piece only have to advance some 40 to 50 mm to complete the cut.

"Dado"style cross cuts - depending upon your technique and the width of the dado and width of stock being cut, the riving knife / splitter may require removal as few designs allow the riving knife to be lowered to the top of the saw blade, for single blade cuts. Dado stacks require a similar approach with the riving knife / splitter generally being ineffective anyway.

Large Panel Rips - I set the adjustable rip fence to full table width and always use the riving knife / splitter and blade guard and provide support for the panel rip & waste in & out of the saw table.

Small Panel Rips - I typically set the adjustable rip fence to full table width and always use the riving knife / splitter and blade guard, because I use pad push blocks. Again technique depends upon the width of the rip. The ratio of panel length to width also dictates procedure as some "rips" are best performed using the crosscut / mitre fence.

Long board rips - I typically set the adjustable rip fence to full table width and always use the riving knife / splitter and blade guard BUT may adjust this depending upon how the stock responds to the release of tension within the board/s. Again technique depends upon the width of the rip.

Short board rips - My preference is to set the adjustable rip fence to just past blade center and always use a push stick, the riving knife / splitter and blade guard BUT may adjust this depending upon stock length and the release of tension within the board/s.

Ripping long thin stock < 5 - 6 mm - My preference is to set the adjustable rip fence to just past blade center for longer work and always use a push block that is supported by a taller auxillary fence attached to the main fence, the riving knife / splitter is fitted, but blade guard removed and feather boards used. Where practical I fit a blade guard.

Ripping short thin stock - again depending upon length 300 mm + I tend to use the GRR-Ripper system. Under 300 mm best performed on a custom sled.

I am also a devotee of the GRR-Ripper system for ripping which I use regularly. I know many do not approve of them. To pinch Liam Neeson's line from the movie "Taken" - "but what I do have are a very particular set of skills. Skills I have acquired over a very long career. Skills that make me ...." well safer! Yes they present potential hazards, and so do all of the above tasks, however in particular circumstances they have a much lower risk profile.

I also have a particular and non-typical requirement for cutting very small components on the table saw to make inlay banding & the like which require considerable innovation to complete successfully. Some of which go against mainstream "standard work practices" so I am loathe to share them because they do require "a very particular set of skills. Skills I have acquired over a very long career. "

Originally Posted by BobL

Maybe don't take any notice of me as I don't use a riving knife either - I took it off in 2006.

Bob what is the reason for not using a riving knife?

Originally Posted by jimfish

Bob what is the reason for not using a riving knife?

The original riving knife on my contractor saw was integrated into the OH guard/hood and did not rises and fall with the blade. As the hood was a poor dust collector I took it off and replaced it with a series of different kinds of hood. Had this not been the case I would have left it there and I definitely don't recommend taking off the riving knife for no good reason. I have been meaning to make a new knife for some time but as there's no rise and fall mechanism for the knife its a lot more work than it first appears. As a intermediated approach I am considering just adding an easily removable stubby splitter

My current TS guard is pretty hefty and does a really good job at holding work pieces down onto the table so should reduce (but not eliminate) kickback.
As long as my main fence is set parallel to the blade (its worn and not as good as it once was) when using the auxillary short I don't have problems.
The wild card is cutting wood that pinches the back of the blade. I used to have this problem when I was using all sorts of salvaged/green timber but less so in the last few years.

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