The short answer is no. A jointer flattens one face (or edge), but to make the opposite face flat and parallel, you need to use a planer.

Some people seem to use the term "jointer-planer" when they really mean "jointer". Then there are the European style combination machines that actually are the two machines in one.

To make an opposite edge parallel, you wouldn't use a planer, rather you'd run the piece thru your table saw. You don't want to run a board thru a planer on its edge as it would not be stable oriented that way.

 

There are no stupid questions. Dwight pretty much has it right. The most important thing of all is put your heart into it, have fun, and don't give up. May you always be happy in your work.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com

 

I think it has to do with what generation your from .I have a friend that's in his 80s and he calls a jointer a jointer planner. In essence you can plan with a jointer but just face plan not thickness plan.

 

You can thickness with a jointer. I'm aware of 2 ways
to do it.

1. build an elaborate jig like the planer attachment similar
to the one used on the INCA 410.

I have some plans around somewhere of such a jig. I bought
them on ebay some years ago. They were torn from an
old handyman magazine from the 1960s.

2. Use the method developed by Tage Frid and described
in an old Fine Woodworking issue.

 

If you did not have a planer, could you use a router sled? Similar to how you flatten cutting boards.

 

Yes after jointing one side.

 

Yeah, but it's pretty slow.

There's also something called a safe-t-planer which
you chuck into a drill press attach to the auxiliary
arbor on a radial arm saw.

 

You can also do it the old fashion way with hand planes ,some folks prefer to do it that way.

 

double post…see below

 

Two different tools, with different primary functions, though there are some similarities. The jointer's primary job is to flatten a reference face, and then an adjacent 90° edge to that face…..everything other aspect of dimensioning lumber references to that flat face and squared edge.

A planer essentially makes the opposite face parallel to the bottom face, and produces a consistent thickness across the length of a board…note that it doesn't flatten a board per se…a board that's twisted will come out twisted, but thinner. A planer needs a flat board face to reference from so it it can make that opposite face parallel to the reference face. With the help of a planer sled to substitute as a reference face, a planer can be coaxed into flattening an opposite face.

It's worth noting that some people skip the flattening of a face and do edge jointing using a table saw or a router, but without a reference face, the ensuing 90° edge isn't uniformly 90° to the entire face….it's random.

 

I agree with a1Jim. The generation you come from means a lot. I was taught to call them jointer/planers because they do plane a face flat. They don't thickness plane. We also learned to call sabre saws….sabre saws. today those are jig saws. We were taught that a jig saw powers a blade. much like a coping saw blade, from the lower end. Today we use smaller, thinner, blasdes on a lighter machine and call it a scroll saw. They are different than jig saws but similiar. Drills are those devices with flutes that you put into the chuck of a drill motor. First the public misuses terms then the marketing people go with them.
I was also taught that wood filler was used for filling grain in the wood before finishing. Wood repair was used for filling holes in he wood.

 

There seems to be contradictory posts in this topic. My understanding is you can joint one edge,
and plane one face of a board on the jointer. Now if you can do one face, why can't you do both ?

I think I missed something.

 

My understanding is you can joint one edge, and plane one face of a board on the jointer. Now if you can do one face, why can't you do both ?

The jointer can make both faces of a board flat, but it can't make them parallel to each other….you usually end up with a wedge if you try. The planer makes the other face parallel to the one flattened on the jointer.

 

You can flatten both faces of a piece of wood on a jointer, assuming the board's width is less than the width of the jointer. What you cannot do is make the two faces parallel (same thickness).

 

The difference is that a planner is made to plane parallel to the jointed face,if you joint both sides ,both sides will be flat but not necessarily parallel to each other.In other words the board may not be of equal thickness just jointing each side.

sorry I guess we were all typeing at the same time.

 

exactly what these guys are saying. You can plane a face or for that matter 2 faces on a jointer. to make them parallel to each other you have to use something else like a thickness planer. If you want to make the edges parallel you need to use something elso like a table saw. If you take rough sawn lumber and put it through a thickness planer and plane both sides you will have a wood wave in most cases. This is the argument for both tools in your shop.

 

Wow! As always, I'm stunned by the quality and usefulness of the feedback that I find here…

So let me see if I'm getting this right… it seems as though the primary difference between a jointer and a planer is not the essence of the machine, but the fences/rollers that allow you to establish a true reference line. They seem to both have an infeed table, an outfeed table, and a rotary cutter. In a jointer, you establish a true line by running the board through the cutter (with tables properly aligned) while holding it firmly against the fence, which is previously established to be perpendicular to the beds.

A planer, by contrast, takes as its reference line not the fence but the opposite face of the workpiece. Hence the twisted in, twisted out issue.

I'm interested in really figuring out this whole issue of true lines… I know this may sound a little "out there" to some, but I'm pretty interested in ancient thought and philosophy, especially the development of mathematics. Now, I'm no good at math whatsoever, but I do think it makes a good story, and interesting reading. Imagining how those ancient people cut square beams for their building… or square stone blocks for that matter… I just find that stuff fascinating. And it's not like it's easy stuff to get a handle on, even if it is all ancient… it takes thought, and experience, and observation. While I went to school for history and I've always been a big reader, I've been a working stiff all my life. Drives me crazy how little respect the manual arts receive. The builders, the cooks, the farmers, the plumbers, the seamstresses, the mechanics… We literally make the world go round. And we know stuff the ivory-tower types don't. We're not a bunch of idiots. It takes a lot of smarts, keeping the world turning. One of my favorite stories: when they built Oxford, they used great big oak beams, from great big ancient oaks. The problem with oak is that, after eight hundred years or so, it just basically fades away. So, eight hundred years after the founding of Oxford, the venerable masters found themselves in a big dilemma. Where would they find oaks of such stature these days? By this time, such woods were rare in Europe. For a year or more they worried over the problem, until finally news of it filtered down to the staff, and to the groundskeepers. They went in to the great halls, and found the venerable masters, and introduced themselves (for they had never met). "We knew about the oak when we built the halls," they said, "and we are ready." They led the learned professors, the great men of science who had despaired over how to repair the halls, to a hidden grove of great oaks-planted by the prescient and learned groundskeepers, eight hundred years ago. Moral of the story: there's a heck of a lot to learn from old-timers.

I wonder if this "jointer-planer" generational thing might not speak to just such a situation. I'd suspect that if the old-timers call them "jointer-planers," there's at least something to it. Maybe not what I expect… I wonder, though. There are three holes in the fence of my jointer. Parallel to the bed. I've puzzled over their purpose. Could they be there to accept some sort of rollers, a la a planer? Looking at the image above, a planer could just as easily have the cutter below, the beds offset, and the rollers in parallel.

 

this explanation of the difference between jointer and a planer should be a forever sticky somewhere. I had to research this question for a month, watch tons of videos to finally understand why you want both machines.

in this sticky, it should show what happens if you use a jointer on a bottom side of a 2×4 that is crooked, and then just flip the 2×4 over on it's top then joint to see WHY a planer is needed

 

...

so what happens?!

Another question springs to mind: given the twisted in/twisted out issue on a planer, what is the method for flattening boards? I can see already that there's a few different approaches. I can see how the edging works: jointer for reference, table saw for parallel edge. I get the planer, tool, twisted in/twisted out. But I don't yet see how the board gets flattened. Where's the reference line? I think I see how a planer sled works… and I can definitely see how the RAS safe-t planer works… but it feels like there must be some kind of dedicated machine for this. Both the sled and the RAS accessory seem like… accessories. Are there planers designed to handle the twisted in/twisted out issue?

And how did the old timers manage the same task?

And to you grumpy forum dwellers who grumble over silly newbie questions… honestly I get a much higher grade of information, much faster, by posing my silly questions here than I do trying to figure out the right string of search terms on google for hour after hour, and wandering through the wilderness on my own. It's freakin' awesome. Not just for the info, the free expertise (how often can you find that?)... but because there's so many great folks out there, willing to spare a second to drop a knowledge bomb on me… awesome. Freakin' awesome.

 

See knotscott's first drawing that's how wood is face planed Or flattened on one side.

 

 

let me take another shot at this.

as i have learned the hard way, when you start any project, you need a starting reference for everything that follows. think of a project that you have 10 1"x1"x1" square blocks stacked ontop of each other. If just one of them is not "referenced" to the first, you will have a leaning tower. all measurements, angles, reference points start with the first flat reference face you did on the first block. you base the entire tower on that first block. this is the purpose of a jointer. to give you that first flat face as a reference for everything else.

you run a 2×4 across a jointer. great, you have your reference point. you flip it over and run the 2×4 across the jointer again. you would think the top and bottom are now perfect. they are not. the top face could be 1degree, 2degrees, etc from the bottom face. and those degrees stack up for every inch.

this is what the planer does. by leaving the first 2×4 jointed face on the bottom, as the 2×4 feeds into the planer cutter heads hitting the top of the 2×4… it is always constantly being referenced against the perfect bottom. end result, perfect parallel top and bottom to EACH other.

plus, with a planer… you can say i just need 1/32" off the top to make the board exactly the size i want. or 1/8th, or 1/4th, etc. Hence the name Thickness planer as you can whittle away at the thickness of a board.

 

"Another question springs to mind: given the twisted in/twisted out issue on a planer, what is the method for flattening boards? "

The knives on the jointer head are positioned precisely at the same height as the outfeed table. The infeed table is slightly lower, and can be adjusted to take a larger or smaller amount off. The difference between the height of the infeed and outfeed tables basically causes the cutterhead to remove all the high spots, until there is no difference between the high spots and the low points. Any deviation in the board that's higher than the height difference of the tables just gets skipped. It often requires multiple passes, depending on how large that difference is, until it's removing the same amount the length of the board. It can be a difficult concept to grasp (and describe) in theory…..eventually a light goes on, and you'll get it.

Here's a pic I plucked from Wood Mag's website:

Here's a series of pics from Stephan Woodworking:

1st pass:

2nd pass:

3rd pass:

And yet another from Happywoodworking.com:

 

Holbs, Jim, knotscott, all of you, thank you, the light just went on.

I get it.

So let's say I have a table saw and a planer (I don't) and let's say I'd like to get a board perfectly straight and square on both faces and both edges. I joint one edge. I make a parallel edge with the table saw. Then, in the jointer, I flatten one face. Then, using that flat face as my reference, I flatten the other face in the planer. Right?

 

Without a jointer, the steps should be to flatten a reference face first with a handplane or planer sled first, then place the opposite side with the planer. Then edge joint an edge with a TS sled or router, then use that edge as a reference against your TS fence to trim to final width.

If you have a jointer, you flatten a face first, put the flat face against the jointer fence and edge joint a 90° square edge, then use the planer on the opposite face, and rip to width on the TS using the jointed edge against the TS fence.

A TS ripping sled for edge jointing without a jointer: