Using a jointer

[Maurice Arney]

Is it always necessary to run boards through a jointer before gluing up? If they are planed smooth and line up square without gaps, should they still be run through a jointer?

Thanks!

[Don Bullock]

I made some very nice table tops long before I bought a jointer.

[Brian Kent]

It is not necessary. Just one good way to do it. I have used a table saw with a great blade and I've used a #7 Plane. Both worked well.

[Neil Brooks]

I genuinely do NOT mean this to sound snarky or sarcastic, but ... it's only necessary if it's necessary.

In other words, if you hold two ripped boards, edge to edge, against a bright light source, and can see NO light where the edges meet, then ... glue 'em up !

But ... not all table saws, with not all blades, leave a glue-line edge, so ... sometimes it really IS a necessity.

For others (like me), it's just so much of a habit that it'd be harder for me to STOP jointing the edges than it would to keep right on going :)

[Frank Drew]

What they said: If you can get a gap-free fit (top and bottom), with either hand pressure or clamps, then you're good to go.

I'm like Neil; I always jointed my edges maybe as much out of habit as anything, but I do think I got cleaner edges from the jointer than from my saw.

[Justin Dreier]

I rarely joint my edges off the table saw. The jointer is used on my end to make one rough sawn board side straight and flat. Then to make twisted boards,etc... flat. I've had good luck with a glueline rip blade and find no need for a jointer in those cases.

[Jerome Hanby]

I've had good luck with my Freud glue line rip blade. If your blade leaves some machining marks, the jointer is a quick way to get rid of them...

Think the other guy had the right of it, if you need it then you need it.

[Mike Cutler]

Is it always necessary to run boards through a jointer before gluing up? If they are planed smooth and line up square without gaps, should they still be run through a jointer?

Thanks!

Nope, but a really good trick is to lay out the boards as if you were going to glue them up, then take the boards, two at a time, fold them like a book, and run them through the jointer together, or the tablesaw.
This gives you two edges that are the compliment of each other, and the glue up may go a little easier.

[Maurice Arney]

Nope, but a really good trick is to lay out the boards as if you were going to glue them up, then take the boards, two at a time, fold them like a book, and run them through the jointer together, or the tablesaw.
This gives you two edges that are the compliment of each other, and the glue up may go a little easier.

Good idea... Thanks!

[Maurice Arney]

Thank you for all the input. As usual, common sense is the key... :)

[glenn bradley]

Late to the party but, if the board face is well prepared and the edge is smooth, straight and perpendicular (unless the design call for something else) I just glue them up. If I have ripped the edge on the table saw, they come off ready for glue up. If I rip them by hand or on the bandsaw, I edge joint.

[Myk Rian]

I use a glue-line rip blade. Never have needed to use a jointer.

[Neil Brooks]

I use a glue-line rip blade. Never have needed to use a jointer.

Slight tangent, but .... even for face jointing rough sawn lumber ?

[David Winer]

Nope, but a really good trick is to lay out the boards as if you were going to glue them up, then take the boards, two at a time, fold them like a book, and run them through the jointer together, or the tablesaw.
This gives you two edges that are the compliment of each other, and the glue up may go a little easier.
I seem to be missing something about this explanation. If the jointing operation should leave a defect, such as a bow in the two boards, the mismatch when re-bookmarking them together would be magnified by a factor of two. At least this is what seems to appear when I picture the technique in my mind.

[Neil Brooks]

I seem to be missing something about this explanation. If the jointing operation should leave a defect, such as a bow in the two boards, the mismatch when re-bookmarking them together would be magnified by a factor of two. At least this is what seems to appear when I picture the technique in my mind.

My take: there would be some risk of that, but it would be a fraction of the time.

The rest of the time, you'd be saving time, and getting that slight bit of additional insurance that your jointing was identical, between the two boards you're gluing.

[Ron Citerone]

Nope, but a really good trick is to lay out the boards as if you were going to glue them up, then take the boards, two at a time, fold them like a book, and run them through the jointer together, or the tablesaw.
This gives you two edges that are the compliment of each other, and the glue up may go a little easier.


I've heard this several times, didn't believe, but a cupped side on my last furniture side has haunted me several times on subsequent steps. I am using this idea from now on!

[Myk Rian]

Slight tangent, but .... even for face jointing rough sawn lumber ?
Did you read the OP?

Of course I use the jointer to work rough sawn. I just don't use it after the stock is cut, worked, and ready for glue-up.

[Kirk Poore]

I seem to be missing something about this explanation. If the jointing operation should leave a defect, such as a bow in the two boards, the mismatch when re-bookmarking them together would be magnified by a factor of two. At least this is what seems to appear when I picture the technique in my mind.

Actually, it's a hand planing trick meant to deal with a case where you aren't planing square to the faces of the boards. The result would be complmentary angles on the planed edges. It should work on a jointer if you aren't holding the boards up against the fence, or if the fence itself isn't perpendicular to the table.

However, as you point out, David, it doesn't do anything for lengthwise defects caused by poor technique. In fact, it would double those errors. So I would't do it.

Kirk

[Jon van der Linden]

Actually, it's a hand planing trick meant to deal with a case where you aren't planing square to the faces of the boards. The result would be complmentary angles on the planed edges. It should work on a jointer if you aren't holding the boards up against the fence, or if the fence itself isn't perpendicular to the table.

However, as you point out, David, it doesn't do anything for lengthwise defects caused by poor technique. In fact, it would double those errors. So I would't do it.

Kirk

It wouldn't double those errors. The lengthwise errors would remain the same. Errors on single boards are always multiplied when jointing. That said, jointing two boards at once on a jointer would be very awkward. When jointing by hand it creates a wider surface for the plane to run on (less prone to rocking), as well as creating complementary angles.

OP: As long as the boards match up exactly it doesn't matter how you got there. The main thing is they should fit perfectly without any pressure. If they are not "perfectly flat" the joints should have a slight concave, and by slight I mean much less than the thickness of a sheet of paper. I'd aim for a concave of less than a thousandth. You can easily check for this with a straight edge.