- Step 1: What is a jointer? Understand what a jointer is: a machine for leveling off pieces of rough wood.
- Step 2: Locate the high corners Determine the high corners of the planks and mark them--these are the points where you will apply the most pressure to level them out.
- TIP: Using a push pad Use a push pad to apply pressure to the front of the plank and a push stick to apply pressure to the back and to guide the plank along.
- Step 3: Checking the height difference Before cutting, make sure the difference between the two table heights is where you want it. Also, the fence should be at 90 degrees. Lock all adjustments in place. Repeat the same process with the edges and use an engineer’s square to ensure levelness.
When you buy rough lumber for woodworking projects, you'll occasionally get
a board that has a bow or a twist in it. And in order to work on the
machines, like the table saw, you need to have the faces flat and the edges
square. So, one of the first machines you're going to have to use to fix that
bow in the face of the wood, is a jointer. What it is, is a cylindrical set
of blades, that are down in the bed of this machine. The way that the
machine works, in the most basic way, is that you're starting on an infeed
table that's slightly lower than the blades and the outfeed table. The
blades and the outfeed table are at the same height. So it's essentially
going into a little cliff of blades that shave off a small amount, and then
you end up at the new height, on the outfeed table.
This board, for instance, here, that I have, has a little bit of twist to
it. You can see there's a high and low point. If I push down on the
corners, these ones are relatively stable; these ones really move. That
means that these are the high corners. So, I'm going to mark those, and we're
going to find the face that's the least twisted, and work on that one. It's
definitely the first one. Okay. You find those high points, mark them, those
are the points we're going to try and lower on the jointer.
Now, the technique for doing this is to use a push pad to hold the wood
down at the front. And, you'll use a push stick on the back, to push the
wood forward. In the case of a twisted board, and this is the most kind of
advanced thing you'll do on a jointer, you're going to have to put extra
pressure down on those high points as you're passing this through. Regular
pressure on the rest of the board as it passes over, and then high pressure
again on the other corner as it's passing through. So, it's a little bit of
a coordination exercise, but I'll try and demonstrate it for you. If this
board weren't twisted and we were just trying to flatten the face, maybe
there's a slight bow, we would just be passing the board over uniformly. As
soon as it gets on the outfeed table, you're putting all of your downward
pressure over there, to keep it at that new height, and just pushing it
One thing to take note of, is before you do any cutting on the jointer,
you're going to want to, just verify the difference in the table heights. The
easiest way to do that - rather than relying on one of these gauges, which
may not be accurate - is to put a straight edge or square on the outfeed
table, and look at the height difference on the infeed table. Just by
looking at that, just eyeballing it, it looks to be about 1/32 of an inch.
It's not very much, you can adjust that, if you wanted to , make it more
aggressive. This table can be raised and lowered. You just have to unlock
it in the back, and grasp this clutch, raise and lower it, so you can make
it a very aggressive cut by lowering it, or bring it up and make it a
lesser aggressive cut. Just lock it when you're done.
Now while we have the square, the other thing to check on a jointer, is to
make sure the back fence is indeed 90 degrees to your outfeed table. If
it's not, this fence can also be adjusted. There's a lock that lets this
fence bevel, so you can do angled cuts against the jointer blades , but
sometimes that gets out of square if people use it and don't put it back
right. So, just double-check, and make sure you're totally square.
Okay, that's locked in place. The last adjustment you'll make on a jointer is
the width of the cut. I just have a six inch-wide jointer, that's the maximum
I can do, but if I was working on a narrow board, I would want to expose
less of this blade. There's no reason to use the whole blade if you don't
need to. So, on my board, I'm only about four inches. That should cover it.
And we'll lock it down. So, let's go ahead and run this through, and see
Okay. The face is jointed now, it should be relatively flat if I push down on
the right places. Much better. High points are basically eliminated. Once
you go to the planer and do the opposite face, you can come back to the
jointer, and do the edges. So, let's see - we have two parallel flat faces
on this board. And we'll index off the back fence, and create a 90 degree
angle at the bottom edge. This is how you start squaring up your board.
You get two faces parallel, and then you get one edge perpendicular to
those faces, and then you do the last face on the table saw. So, let's just
look at how we joint an edge.
It's a similar procedure. The pressure points are the same. You really only
want toput downward pressure once you're over on the outfeed table.
Depending on the initial condition of this edge, whether it was bowed or
not, you may need to run it through again. One way to check it, just
quickly, is to put it against the back fence of the jointer, and you can
see if there's a seam or not. But really, the ultimate test is going to be
with a square. You're going to want to make sure that that face and the edge are
truly perpendicular, and you can sight down with a square, using a very
accurate square like an engineer's square like this , and just make sure
you don't see any gaps happening.
All right. And that's it for the jointer.