Advice on using a jointer

[Jake]

I have a new jointer. I never used on before. Not surprisingly, I'm trying to mill some rough stock to make glued up panels. The stock isn't that rough. I joint one edge straight, then put that edge against the fence and do the faces of the board. Then I cut the other edge on the table saw and joint that too. My problem is that the board is not square when I'm done. The faces of the board are not exactly parallel. In other words, one edge is slightly thicker than the other. (I don't have a planer or I would use that.) I have checked the fence with 3 different squares and it appears to be exactly at 90 degrees. What am I doing wrong?

[David]

Nothing. You need a planer to get the faces parallel. That's because a planer references the first (and only) face that you've run through the jointer. the jointed face goes against the table of the planer. That's why it's the machine to use AFTER making ONE edge and ONE face flat (and perpendicular to each other) on the jointer.

Dave

[David]

Wouldn't it be easier to joint one face first, and then hold that face against the jointer fence to make the first edge perpendicular to that face? ie I can't feature trying to hold a thin edge against the fence in order to assure the first face will be jointed correctly. Maybe you've got some technique I've never mastered.

dave

[Chuck Taylor]

A jointer can't do the job of a planer. It can make the faces flat but it can't make them parallel.

[Mike O.]

You might check to see if the knives are parrallel with the table(s). It's possible that the knives are higher on one end of the spindle.

If you have a dial indicator you can just check the blade height in relationship to the table.

If not, you can just make a quick (not so scientific) check with a scrap of wood. With the machine unplugged, try taking a pretty straight piece of scrap and lay it on the out-feed table against the fence and let it hang over the spindle. Turn the spindle (or pulley) by hand until the knife touches the wood. Now raise the out-feed table until the blade barely nicks the wood....almost not touching. Now just slide the piece of wood over to the outside of the spindle (away from the fence) and see if the blade barely nicks the wood on that side of the table. If the blade touches on one side and not the other or barley nicks on one side and raises the scrap on the other, then it's time to re-set the knives

Mike O.

[David]

Tell me your kidding, based on the OP's symptoms!

Dave

[Billy Smith]

There is a definite sequence of steps to square and true a workpiece. Each step requires a certain kind of equipment and produces part of the solution, e.g. a jointer by itself will give you one flat face and one straight edge square to the flat face. But, in general, you cannot produce two flat faces and two straight edges, with everything perpendicular and parallel, using only a jointer.

If you are getting the second edge straight by using a table saw, then all you need is to plane the second face parallel to the first one. A planer will do it but if you have the desire to learn it, you could do the planing by hand. You'd have to acquire a couple of good hand planes (total cost could be around that of a power planer) and it takes longer but there are advantages to being able to do the planing by hand. Many of us just like doing the planing by hand.

You can find some good lessons on how to "true up" stock either in a book on woodworking techniques or by searching around on the web.

[Mike O.]

I believe what he said is that the faces are not parallel after jointing both faces. I did assume that they probably were when he started. While I agree that a planer might be better suited to his needs, knives that are not installed properly on a joiner can cause just the problem he describes. I also did not say it WAS his problem I said he might want to check his knives for proper installation.

Mike O.

[Dave Jackson]

Read this:

--dave

[Doug Miller]

Two things: one, jointing the edge first and then the face (should be the other way around); two, expecting a jointer to make opposite faces of the board parallel. A jointer makes a surface flat. That's all it does. There is simply no way to ensure that the second face is parallel to the first. That's what a planer is for (or hand planes).

The proper sequence is:

1) joint one face straight and true 2) joint one edge straight and true, and square to the jointed face 3) plane the second face parallel to the first 4) ripsaw the second edge parallel to the first

The order can be altered slightly: #1 must come first, and #2 must precede #4. So you could do it 1-3-2-4 or 1-2-4-3 also.

[Doug Miller]

Right -- which is exactly what one would expect from the procedure he described.

The OP explicitly stated he's working with rough stock, so this seems unlikely.

So does trying to use a jointer to do the job of a planer. Even if the knives are perfectly aligned, you *still* can't joint opposite faces of a board parallel except by luck.

[Phisherman]

Do one face against the jointer, then use a surface planer (else your stock won't have parallel faces). It would be preferable to use a surface planer (rather than a jointer on one side) on BOTH of the large faces--much safer too!

[Doug Miller]

Note that this does not mean to use the planer *only* and not the jointer. Rather, it means use the jointer on one face first, plane the second face parallel to the first, and then plane the first face. Jointing and then planing leaves a smoother surface than jointing alone.

[noonenparticular]

First thing, think FEE when prepping rough stock. Faces, Edges, Ends. The reason you do the face before the edge is so you have a larger face bearing against the fence during step 2 to ensure squareness. Of course, ends won't apply until you get the stock off your jointer and get done planing the opposite face, but you get the idea. Flatten a face, plane the opposite face parallel, joint the edges, then square the ends. This doesn't address your issue of getting the faces parallel. This is what a planer or a sharp plane and a marking gauge are for.

hth,

jc

[Mike Berger]

I don't see why this is the case.

Joint one side of the board flat. Using your properly aligned fence, joint the adjoining side to be exactly perpendicular. Now use THAT side to reference the next adjoining side to be exactly perpendicular. Then you can use that to make the final side perpendicular. Thus, all opposite sides would be parallel to each other, just like a planer would do.

Of course if the edges are significantly smaller than the other surfaces, this could be difficult to do. C> A jointer can't do the job of a planer. It can make the faces flat

[Chuck Taylor]

Aside from the practical difficulties of that procedure, it will *not* yield uniform thickness along the length of the stock.

[Chris Friesen]

This just ensures that each corner along the edge is 90 degrees when measured perpendicular to the edge. It doesn't ensure that the corners along each *end* are also 90 degrees.

Thus, the board can taper from one end to the other, like a wedge.

Chris

[DonkeyHody]

If you get parallel faces by that method it will be because you were lucky and not because you were good. A board could be shaped like a pyramid and still have all 4 faces perpendicular to each other.

DonkeyHody "Even an old blind hog finds an acorn every now and then."

[David]

"Fairly square stock"? let's just skip all the jointing then!

Mike, a jointer does not produce parallel faces except by luck. A planer uses the flat face as a reference to plane the second, and opposite, face parallel to the first one.

Dave

[David]

Doug, not speaking for anyone else, but when I joint a board at the proper rate, the results are nearly indistinguishable from what comes out of the planer. Granted, if I go too fast, it's not as smooth. Regardless, sanding or scraping is required for top notch results, so I don't see why it's necessary to run the jointed face through the planer unless one is cleaning up some obvious problem visible after jointing.

Dave