Dovetails and Plywood

My cousin, Michael, asked me to make a wooden box to store his torque wrench.  When he gave me the wrench so I could make the box to fit, he told me, “It doesn’t need to be anything fancy – just something to protect it.”  My job was just to make the box and he intended to line it with foam.

I didn’t have much in the way of non-fancy materials in my shop.  I was tempted to use some red oak but ultimately decided to use up some narrow strips of 1/2″ poplar plywood.  (Unlike most hardwood plywoods which have stupidly-thin veneers that splinter when you sneeze at them, this plywood is made of nice thick veneers.  This plywood is 1/2″ thick and has three layers.  You do the math.  This is my favourite plywood.)

At the tablesaw, I cut the six parts to size and milled grooves in the long sides for the bottom and sliding top.

I could have simply glued and nailed the corners, but I felt inspired.  So I dovetailed the corners.  No, they weren’t the best joints I’ve cut, but this application did not demand fine joinery.  These dovetails provided some visual interest and mechanical strength.  And that’s what mattered.  Yes, I used wood putty.  And yes, I missed a spot.  And no, I wasn’t concerned.

I decided to try the time-lapse function on my new video camera so I set it up when I cut the dovetails.  When I shot the video it was dark outside so I was in full control of the lighting.  A single fluorescent magnifying lamp directly over the bench illuminated the workspace.  I set the camera to take a picture every 10 seconds while I cut dovetails for a box.

This is definitely an experimental video.  Please let me know what you think of it.  (I’ll cover my strange dovetailing techniques in a future post.)

Wall Brackets for Hollow Chisel Mortiser

Yesterday, at 2:05 pm, I decided that I needed to get my benchtop mortiser off my bench.  I documented the process of building and mounting wall brackets live on Twitter and what you see below are the updates.  This was useful because each update had a time stamp so followers could see the rate at which I progressed.

(If you are not familiar with the format used on Twitter, the @ symbol indicates a username.  Every update, or “tweet” below starts with a username and they are the author of that tweet.  Sometimes, you will see two or more usernames in a tweet.  The second (and third, etc) usernames are people to whom the author is talking.  The other symbol you will see is #, which serves as a category.  I tried to remember to categorize all my tweets pertaining to this project under #flairww.)

@FlairWoodworks: I need a pair of brackets to mount my mortiser on the wall here. Follow along with #flairww
January 10, 2012, 2:05 pm

@FlairWoodworks: This is my mortiser. #flairww
January 10, 2012, 2:06 pm

@FlairWoodworks: These are some hardwood scraps I had in the shop. The wood on the right is interesting but there isn’t enough. #flairww
January 10, 2012, 2:13 pm

@FlairWoodworks: I use a short fence on my sliding tablesaw to cut the parts to length. #flairww
January 10, 2012, 2:17 pm

@FlairWoodworks: I used the jointer to flatten one face, then used the bandsaw to make the other face parallel. #flairww
January 10, 2012, 2:22 pm

@FlairWoodworks: I used the smallest of my seven bench planes to clean up the bandsawn surfaces. This wasn’t really necessary though.
January 10, 2012, 2:34 pm

@FlairWoodworks: I dry-fit the bracket and marked the cuts for the cross-brace. #flairww
January 10, 2012, 2:38 pm

@FlairWoodworks: Some of the cuts for the cross braces were angles greater than 45 degrees. This is how I cut them. #flairww
January 10, 2012, 2:50 pm

@DyamiPlotke: @FlairWoodworks great, simple strategy.
January 10, 2012, 2:50 pm

@FlairWoodworks: Here’s your first look at what they will look. #flairww
January 10, 2012, 2:52 pm

@FlairWoodworks: I’m using 8mm Dominoes for the joinery so I had to switch the bits from the last time I used the Domino Joiner. #flairww
January 10, 2012, 2:56 pm

@FlairWoodworks: To get this mortise accurately cut, I clamped a stop 10mm down from the centerline. #flairww
January 10, 2012, 3:08 pm

@FlairWoodworks: I forgot to readjust the depth setting for the angled ends. I’ll plug this cavity with a Domino and try again. #flairww
January 10, 2012, 3:14 pm

@FlairWoodworks: One glued up! #flairww
January 10, 2012, 3:26 pm

@FlairWoodworks: I use Extractor nail pullers to remove the Dominoes after dry-fitting. #flairww
January 10, 2012, 3:41 pm

@DyamiPlotke: @FlairWoodworks good idea. I use pliers.
January 10, 2012, 3:55 pm

@FlairWoodworks: @DyamiPlotke The jaws of the Extractors remain parallel for a better grip.
January 10, 2012, 3:56 pm

@DyamiPlotke: @FlairWoodworks yeah. I’ll try an extractor next time.
January 11, 2012, 4:00 pm

@FlairWoodworks: The glue is dry now so it’s time to continue making the brackets for wall-mount the hollow chisel mortiser.
January 11, 2012, 5:20 pm

@FlairWoodworks: The next step is to flush up the joints. #flairww
January 11, 2012, 5:22 pm

@FlairWoodworks: If the brackets are out of square, I use the tablesaw to cut them square. #flairww
January 11, 2012, 5:34 pm

@FlairWoodworks: I drilled two angled holes at the top and one straight at the bottom. #flairww
January 11, 2012, 5:45 pm

@FlairWoodworks: I attach one bracket at the measured height on the wall and use a level to determine the vertical placement of the second.
January 11, 2012, 5:58 pm

@FlairWoodworks: Finally, I hefted the mortiser onto the brackets and bolted it down. #flairww
January 11, 2012, 6:16 pm

@woodbard: @FlairWoodworks Well done, Chris! The mortiser has found a permanent home, out of the way of other tools. Support planned for long boards?
January 11, 2012, 6:20 pm

@FlairWoodworks: @woodbard And it only took two months! When I need outfeed support, I will probably just set up a sawhorse.
January 11, 2012, 6:24 pm

Why Not a SawStop?

First of all, if you are not familiar with SawStop technology you should look into it.  Basically, the saw detects when the blade comes in contact with something conductive such as your finger.  When that happens, the aluminum brake is rammed into the blade stopping the blade’s rotation, saving your fingers.  This video shows how it works and you can find additional information, including the owner’s manuals, on the SawStop website.

This seems like a logical follow-up to my last post about my sliding table saw which cost about the same amount as a SawStop Professional (the Contractor model is less; the Industrial is more).  When I decided to replace my under-powered contractor’s saw, the SawStop was the other saw at which I was looking.  I use a SawStop Industrial table saw at the Lee Valley Tools Ltd. shop where I work part-time so I have first-hand experience with their machines.  They are nicely built and there are many reasons to buy a SawStop:

  1. Peace of mind.  I am the only user of my table saw in my own shop and I trust myself to make smart, safe decisions.  I am comfortable with the saw and understand how to use it safely.  However, if I had someone else using the saw, regardless of their experience, I would feel badly if they had an accident.  For that reason, I am the only one who uses my saw.  If I had others using my saw, I would seriously reconsider investing in a SawStop.
    In writing this, I do not mean to say that I am immune to accidents.  I am not.  In a moment where I am not thinking, the SawStop could well be the difference between losing a finger or not;
  2. Excellent dust collection capabilities, especially when using the blade guard;
  3. The owner’s manual is very clear and well-written.  It is riddled with large, quality pictures.  The manual for the SawStop Industrial Cabinet Saw consists of 104 pages and is coil bound.  There is a separate manual for the fence system;
  4. Adjustments.  The SawStop Industrial Cabinet Saw allows you to adjust more than the 45- and 90-degree bevel stops.  You can also fine-tune the amount of backlash in the adjustments, elevation limit stops, and more.  There are 21 pages dedicated to adjustments in the Industrial Cabinet Saw manual;
  5. Changing between the riving knife (or spreader, as the manual calls it) with blade guard and low profile riving knife (sometimes called a “shark fin”) is quick, easy, and requires no tools; and
  6. They are well-made.  All the machining is fine and you won’t find any cheap plastic components anywhere.  I approve of their hand wheels, which are particularly nice!

Ultimately, a number of factors led to my decision to go with the European-style sliding table saw.  Here is a list of things that helped me decide:

  1. The biggest, of course, was the sliding table.  When I bought my saw, I commented that if SawStop made a sliding table saw, I would buy it.  The sliding table makes wide crosscuts easy and provides ample support for large panels without the need for roller stands;
  2. Though sheet goods are not my favourite, the scoring blade is a useful accessory.  SawStop does not offer a saw with one;
  3. My previous table saw was equipped with a Unifence which I’d gotten use to after learning on a Biesemeyer fence.  The two black knobs on the right side of the body can be loosened, allowing the aluminum fence to be slid forwards or backwards.  This is useful for repetitive crosscuts, as a short fence, or to allow long crosscuts without losing the rip fence’s positioning.

    Delta Unifence

    Fences on European saws are similar to the Unifence in appearance and operation, but may vary in how its position is read.  Rather than the hairline cursors we North Americans are familiar with, some European fences are read directly off the face of the fence.  This is not necessarily better – just different.  You have to make sure you are sighting directly down the fence for an accurate reading.  If you have an auxiliary or sacrificial fence installed, you don’t need to factor in its thickness;
    I prefer the type of fence that can be slid forwards and backwards along the body.  The SawStop comes with one of two models of two T-fences.  Of course, you could always retrofit the SawStop with an aftermarket fence.

    Reading the Position of a European Fence

  4. SawStop table saws tilt left.  Right-tilting arbors are not available.  I prefer a right-tilt saw for the one reason that the arbor flange is on the right side of the blade.  This means that when you put a dado stack on the saw, the additional blades are built away from the fence so the fence’s scale remains accurate.  The opposite is true for a left-tilt saw;
  5. Separate brake cartridges must be purchased for 8″ dado blades.  There is no brake cartridge available for other sized dado blades;
  6. With the exception of 8″ dado stacks, blades other than 10″ may not be used.  I sometimes find a 7-1/4″ blade from a circular saw really useful because they have a thinner kerf.  It’s not often when I need to make a very thin groove, but when I do, a circular saw blade usually does the trick.  They are also cheaper so I am not hesitant to cut dirty lumber with them;
  7. The brake must be checked and set for the proper distance to the blade.  All 10″ blades are not the same.  Sharpenings can have an effect on the size of the blade so if you have a brand new crosscut blade and a thrice-sharpened rip blade, you may need to adjust the brake when switching blades;
  8. When the SawStop’s main power switch is turned on, the saw must do self-diagnostics which takes about 5-10 seconds.  This switch does not need to be turned off every time the saw is turned off;

    Photo from SawStop Manual

  9. The SawStop’s paddle switch used to start and stop the blade just like on a regular saw is easy to bump into accidentally.  I have no issue with that.  However, unlike conventional saws, if the SawStop’s switch is bumped off it cannot be turned back on until the blade has come to a stop.  I find that to be a nuisance; and
  10. The SawStop cannot be run without a brake cartridge installed.  If you don’t have a spare, you can’t use the saw.

While researching for this article I learned something about the saw that surprised me:  in most cases, nails and staples are not large enough to trigger the brake.  However, if the nail or staple is grounded (in contact) with a larger conductive body such as a metal miter gauge, table top, or your fingers, the brake will be triggered.

And according to the website, counter to what seems to be the “general knowledge” most wet or green lumber can be cut on the SawStop without overriding the safety feature.  The SawStop website states that “if the wood is very green or wet (for example, wet enough to spray a mist when cutting), or if the wood is both wet and pressure treated, then the wood may be sufficiently conductive to trigger the brake.”  If you have material this wet, you can either set it aside for a day or so to dry out or set the saw in bypass mode to disable the brake.  By the way, you cannot run the saw in bypass mode without a brake installed.

The brake cartridges record information about an accident.  If the accident involved contact with skin, send the cartridge back to SawStop and they will send you a new one free of charge.  When the brake fires, usually one or two teeth are damaged.  The blade can be either repaired by a blade sharpening service or replaced.  Your choice will likely be dependant on the cost of the blade.

It’s important to note also that the SawStop brake alone does not make for a safe table saw.  Kickback is still a threat, though the included riving knives go a long way to prevent that.  As advanced as table saw safety has come, there is still no substitute for training, experience, good judgement and alertness.

Why a Sliding Table Saw with Scoring Blade?

Most hobbyist woodworkers are impressed when they see my saw.  It’s a big piece of machinery, especially with the 5′ sliding table and outrigger.  And for many of them, it’s something they’ve never seen, or even imagined before.

When I tell someone who has seen this type of machine before, they nod in approval and assume that I work with a lot of sheet goods.  That’s a fair guess, as the saw does excel at cutting up plywood.

If you’ve ever tried to break down a sheet of plywood on a table saw, you’ll fully understand the benefits of a sliding table saw.  When ripping, instead of fighting the plywood across the saw, trying to maintain an even feed rate while keeping the edge against the fence and struggling to support it throughout the cut, it’s a simple matter of loading the plywood on the sliding table, setting it against the fence, and pushing the plywood and sliding table past the blade.  It’s almost effortless.  Need a 4′ wide sheet cross-cut?  No problem.  Set the plywood against the cross-cut fence and push it through.  Here’s a short demonstration of breaking down a sheet of plywood.

The sliding table is half of why this type of saw excels at working with sheet goods.  The scoring blade is the other half.  A scoring blade is a small blade located in front of the main blade.  It cuts a kerf slightly wider than the main blade and is installed so the teeth point backwards and it counter-rotates, or turns the opposite way.  It is set very low, just low enough to nick, or score, the bottom surface of the material being cut.  It counter-rotates to ensure a clean cut on the bottom edge of the plywood – the face of the plywood is supported by the core so there is no tearout.  Of course, having a blade rotating in the wrong direction, trying to pull the stock forward could be very dangerous in theory.  However, because the blade is taking such a light cut, the weight of the material it is cutting is enough to keep the scoring blade from pulling it forward.  Here is a very short clip of the scoring blade in use.

Yes, sliding table saws with scoring blades are great for plywood.

But that’s not why I bought mine.  Plywood is great for some things, but my designs don’t have much use for plywood.  Besides, my workshop is not large enough to easily manage a full sheet of plywood.  Most of my work uses solid wood, and I feel my saw is equally advantageous.  The sliding table is great for straight line ripping.  That’s when I have a rough piece of lumber with no straight edges.  Without this saw, I would joint one face and one edge, then rip the other edge.  But now, I just clamp the piece of lumber to the sliding table and push it past the blade for a straight cut.  Then I turn it around and use the fence to get the other edge straight and parallel.  I’ve rarely used my jointer to edge-joint since I got this saw.  It’s a big time saver – especially when the edge isn’t close to being straight.

Straight line ripping is half of the reason I bought this saw.  The other half is to do wide crosscuts.  With my old contractor’s saw, small cuts were easy with the miter gauge.  Crosscuts up to about a foot or so were manageable with a sled, but wider cuts required a circular saw.

A few advantages that I hadn’t thought about when choosing a saw include cutting tapers and small parts.  Tapers are a simple matter of clamping the stock to the sliding table at the intended angle and making the cut.  With a conventional table saw, small parts can be a challenge to cut safely, but with the hold-down clamp I just position the part, clamp it down, and can safely cut the part while standing at the end out of the outrigger, a full 3′ away from the blade.  I am very glad that I ordered the hold-down.  Another advantage is that all the clutter that sometimes ends up on the table doesn’t get in your way… as long as it’s on the sliding table.  Instead, it just moves with you.

A couple other niceties that this saw has, but aren’t exclusive to a sliding table saw include the european-style fence (similar to the Unifence) which can be used in the short configuration where the fence is slid forwards so that it at the leading edge of the blade.  This virtually eliminates any chance of stock getting trapped between the fence and blade.  I use the short fence a lot for ripping cuts and repetitive cross-cuts.  The 5 HP motor is certainly nice too.  Blade changes are made easy thanks to an arbor lock and a single wrench after moving the sliding table to the forward-most position.  This video was taken soon after I got the saw; I am now more efficient at changing blades but the procedure remains the same.

Working with Melamine Particle Board

Furniture is what I primarily make, and I think that solid wood is the best choice of materials.  No two pieces are identical, and its consistent nature lends itself well to carving – there is no risk of cutting through one layer into another creating an ugly seam.

But solid wood is not always the best material.  Recently, I made some utilitarian cabinets using melamine-covered particle board.  I don’t know if I’ve ever worked with this material, but over the past few days I became aware of some of its nuances and nuisances.

Like MDF, it is flat.  And heavy.  Sheets of plywood on the other hand are often warped, especially if stored improperly.

Like the veneers on most plywoods, the melamine skin is very thin and chips easily.  I am fortunate to have a scoring blade on my table saw which produces flawless cuts.  Because the scoring blade protrudes above the table by only about 1/16″ or so the material being cut must be flat or the scoring blade won’t do its job.

Joints that are meant to be even have to be even when assembled.  You don’t have much opportunity to flush them afterwards, especially if you’ve already edge-banded them (which is easiest).

Particle board is fragile.  Drop it and a corner will likely be destroyed.  It is not nearly as tough as plywood or solid wood.  It also has less strength, so it can sag even under its own weight if not supported.

White melamine can be clearly marked on with pencil and easily cleaned with a damp cloth.

Pre-glued melamine edging, applied with an iron, is easy to apply.  Use the iron to activate the glue, then press it down with a block of wood to ensure good contact.  Being a hand-plane guy, I used a metal-bodied plane with its blade retracted.  My logic is that the plane is easy to hold and the iron sole acts as a heat sink, quickly cooling down and setting the glue.

If you have a lot of edging to trim, dedicated tools are a good buy.  Otherwise, a plane iron does a good job but is slower.  Tape over part of the edge so that you don’t accidentally scratch the panel.

It’s prefinished, so no extra work is required.  Once it’s edge-banded and assembled, it’s done!

Prefinished means dealing with glue squeeze-out is a snap.  Just pop off the glue with a chisel.  Because glue won’t stick to the slick melamine surface, that means plain butt joints won’t work.  For these cabinets, I used floating tenons.  Screws could have also worked, but would require the holes to be capped later.

More Adjustments on the Sliding Table Saw

Yesterday, I continued setting up my saw. First, I had a 7′ power cord installed. With power to the saw, I performed the test run, ensuring that the saw started and ran smoothly in the right direction and stopped, and checking that the three off switches worked.

There is one mushroom off switch under the fence rail, one in the magnetic switch below the slider facing the front (in the manual, the front of the saw is actually what I normally think of as the side), and one micro switch in the blade cover that is opened when changing the blades or adjusting the riving knife. Everything worked smoothly and the saw sounds powerful. Very nice.Using a dial indicator, I checked the sliding table for parallelism with the blade.

Finding it to be within a few thousandths of an inch, I checked the fence for parallelism with the slider. I found it to be out by over a tenth of an inch, so I spent about half an hour aligning the fence parallel to the blade (actually toed out by a few thousandths.

Unfortunately with this fence system, there is not adjustment for parallel within the fence body. Adjustments are made by adjusting three sets of nuts that hold the fence rail to the front of the table saw. It took about half a dozen adjustments to get the fence where I wanted it. Next, I squared the miter gauge on the slider to the blade. That was an easy task, involving a square. I set the stop – a set screw and a nut that locks it in place.

Next, I installed and set the riving knife. I set it at a height that would allow the blade guard to sit almost above the teeth – the Freud reps advised me that they recommend setting their blades 1/2 a tooth above the stock. I checked that the riving knife was aligned with the right side of the blade and it was.

One thing I had noticed when I had a look at the saw in the showroom was that the front of the blade guard rested on the table and caught on the miter gauge – it would stop dead until the blade guard was manually lifted. I solved that problem by simply tightening down the bolt that locks the blade guard to the riving knife. The other thing that I didn’t really like was that a pin through the guard behind the mounting bolt prevented the blade guard from pivoted back out of the way, as is necessary when changing blades. I drove out the pin with a punch, then lengthened the slot that fits over the riving knife with a hand saw. With the modifications, the blade guard now swings up about 100 degrees.

Scoring blades are small blades located ahead of the main blade. They rotate the opposite direction and are set about 1/8″ or less above the table. Their purpose is to make a cut in from the bottom to eliminate tearout. It should be just a shade wider than the main blade. Too narrow and there will be tearout on at least one edge of the cut. Too wide, and there will be a shoulder in the cut.

Some scoring blades are two pieces and, like a dado blade, their width is set by adding shims between the blades. The scoring blade provided with my saw however, is one piece. So how do you adjust the width of cut made by a single cutter? The teeth are tapered, that’s how – narrower at the top, wider at the base. By raising the scoring blade, the width of the cut is increased.

The other adjustment is lateral alignment with the main blade. I set the lateral position using a straight edge, referencing off the left side of the saw plates and avoiding contact with the teeth which would affect the alignment. To set the blade height (and thus, the width of cut) of the scoring blade, I started by lowering it further than I though would be necessary so that it would take too narrow of a cut, the end result being tearout at the bottom side of the stock.

I did a test cut and found exactly that. I raised the blade a little and tested again, finding that one adjustment to be all that was needed. It sure is a pleasure seeing clean cuts, top and bottom.

Moving & Assembly of the Sliding Table Saw

Well, yesterday I had a chance to move my saw down to the shop. The weather had warmed up enough to dry up the ground sufficiently to allow the 5″ diameter casters of my mobile base to roll over the grass.

I spent an hour building a ramp over the stairs leading down to my shop using a 4′ skid, two 7′ skids, two solid stools and scraps of plywood. The scraps of plywood screwed to the sides of the ramp were an insurance measure – last week I helped a friend move a jointer/planer and we had a corner roll of the ramp a few times.

Fortunately, on this day the move went so smoothly that the extra insurance measure was not necessary. I was able to slowly move the table saw onto the mobile base myself and had my brother help me guide is slowly down the ramp and into the shop. Twice, the mobile base dug itself into the ground and I needed to wrap moving straps around the front corners of the mobile base and pull upwards/forwards while my brother pushed. It worked fine.

I spent about 3-1/2 hours assembling the saw step by step by myself and had no issues. The steel extension wings are secured to the cast iron table with bolts and set screws to level them. I found out that the trick is to have the set screws protruding more than required, so the far end of the extension wing is angled upwards. Then, gradually back of the set screw while tightening the mounting bolt until it sits level.

This picture shows how the saw will accept a dado stack – at left is the outside arbor flange; in the middle is a spacer; and at right is the fixed inside arbor flange (the arbor nut is not shown).

The next step is to wire in the cord, attach the plug, and plug it in and do a test run.

My New Sliding Table Saw

I’ve been gradually learning more and more about sliding table saws over the past few years, and finally, a couple weeks ago, I made the decision and ordered one.It’s been a bit of a drawn-out process, but yesterday my new saw was delivered into my garage.

I uncrated the saw, took a measurement of the base, and spent the rest of the day fabricating a mobile base. Being such a warm day, I was able to apply three coats of paint to the mobile base. Recreational White is the colour of Tremclad paint that best matches the saw’s cabinet.

This morning, I took inventory of all the parts. Everything was accounted for and I also found a dust collection hose and two hose clamps not listed. I had a little difficulty locating the bolts and washers which were already threaded into their parts, but otherwise, everything was very straightforward. My 4″ brass caliper was very useful in identifying fastener sizes.

Currently, the saw is sitting in my garage. My shop is around back and to get to it, the saw needs to go down the grassy slope, down the twisitng concrete stairs, and across the back yard. To make moving the saw as easy and unexciting as possible, I took off the cast iron table. By the way, the saw feels a lot lighter if you first unscrew the brackets holding the saw to the pallet on which you are standing!

I was impressed with the machining on the cast iron table.

I also spent a good bit of time cleaning up my shop to make room for the new saw. I think that I will try to keep both table saws operational and in the shop for the time being just to see what it’s like working with two saws. I once had the idea of putting two saws side by side – one in place of the other saw’s extension wing. That way I would have two saws using the same fence rail. I could have one set up for ripping and one for crosscutting. Or with a dado stack.