Jointing long stock.

[Richard McComas]

I read on another forum where someone said when face or edge jointing stock that is longer that your jointer tables you should run the stock with the crown down. This is contrary to anything thing I have ever read, saw, or done myself.

My question is this, is this good advice or misinformation? I think it’s miss information but then about the time I think I know it all someone teaches me different.

What do you think?

[Jim Becker]

Makes no sense to me, Rich, for flattening or edge preparation. I'd really like to know the reasoning on this, too!

[Thomas Canfield]

I am just a novice with the jointer but yesterday I had to run some 6' long 5/4 oak on my jointer. The problem with running the crown up is that the board is continuing to run on a curve as the end section reaches the bed raising the tailing end of the board. I compensated some by only running about 1/3 of the board that was cutting and then switching ends and doing the other end. A couple of passes resulted in removing a large section of the bow and allowed a straight edge to be obtained with a couple of more passes. In that way, the lower curve was worked out. One of my problems was the amount of waste on the crown side, or else I might have tried to start the board mid-way with the crown down to get a flat section to work from. Hope this might help and I look forward to a real experienced report.

[Todd Burch]

I typically will run the crown up. However, that's the first of several tests I apply.

The next test, after looking for curve, is grain direction. Or, better yet, grain "directions". If the grain is such that the concave edge is all running the same direction, then it's a no-brainer to run the concave side down.

However, if there are multiple directions of grain, and the concave side down would produce a lot of chip out, and the convex side is better (grain-wise), I will run the convex side down, but cheat.

By cheating, I will not apply pressure to the out feed table side as I joint. I will apply pressure to the cutterhead area, and try to keep the board from rocking too much. Once it stops cutting (the corwned area has fully passed the cutterhead), I pick the board up and start over, making a longer flat edge with each pass. After a few cuts this way, with an aggressive (deep) cut, I'll raise the infeed table and start running the whole board through.

Similarly, when running the convex side down, if one end is excessively errant in the "sticks out too much" department, I will run that end only through the cutterhead a few times, then start running the whole board through. Basically, with both of these techniques, I'm cutting off the high spots without putting divots in otherwise good wood.

You have to follow grain direction when jointing. Any "rule" of doing it this way or that way without regard to grain is short-sighted.

Todd

[Bob Hovde]

Todd is right that grain direction may dictate over other considerations, but many years ago (I'm old enough to say that, now.) I was told that a cupped board would partially straighten out if the crown was planed first. This would result in less being thrown away in the cutting process.

Bob

[Frank Pellow]

Thanks Todd, that's the best advice for jointing stock that I have seen.

I have experimented some and never come up with a good set of guidelines. I think that I have now found the "right" guidelines. But, I will need to wait to try these out until I get back to using jointer which not be until after my workshop has been built and I have purchased a new jointer -probably about a year and a half from now. I will file the guidelines away until then.

[Chris DeHut]

That if the board is not very straight to begin with, I usually draw a straight line on it and run it through the band saw. It only takes a couple of minutes to do this and, if you can cut a moderately straight line with a band saw, a single pass on the jointer cleans up the edge.

The longer, wider, and heavier the board, the more apt I am to start at the band saw - just makes life easier at the jointer.

Chris DeHut

[Jim Becker]

Chris Dehut's comments made me think a bit more. I guess I would say that if I absolutely need to work a long board for some reason, I'll disqualify a board that isn't close to true right from the start. Otherwise, I always break stock down to short pieces before milling to conserve thickness and options. But anytime I have needed to deal with a little bow, it's been "bow up" just like I would with a shorter board. There is merit in the "both directions" advise too...shave off a little on one end until cutting stops, reverse the board and do the same on that end. Then proceed to do the whole length. But again, a big bow just isn't a good situation for a long board to begin with.

[Donnie Raines]

Not that it really matters, but are we sure he/she is saying "crown up" refering to the cup that the board has. Or does it refer to the growth rings of the board...meaning that the "crown" of the growth rings should be face up?

Muddy the water a little bit.....


Donnie Raines

[Tim Sproul]

Chris and others....

if you don't have a bandsaw (or, perhaps aren't so good at getting nice, straight cuts on your bandsaw)....we all (or nearly all) have some sort of circular saw or at least a router or hand held power saber/jig saw. Use one of those and a straight edge guide...a la the type with zero clearance often used for breaking down plywood sheets....this will give you a flat, straight edge. finesse the edge with either power jointer or hand plane.

The bandsaw works well too, but can create problems if you have a "sudden" sway in the cut...leaving a bit that can catch on the end of the infeed table.

[Richard McComas]

Not that it really matters, but are we sure he/she is saying "crown up" refering to the cup that the board has. Or does it refer to the growth rings of the board...meaning that the "crown" of the growth rings should be face up?

Muddy the water a little bit.....


Donnie Raines
The person was referring to the crown or bow over the length of the board.

[Jamie Buxton]

I almost always start face jointing with the concave face down on the jointer table. I find that if I start with the concave face up, the board can rock from end to end. This doesn't produce the straight face I'm trying to get, and can even accentuate the curve.

[Joseph N. Myers]

I've been joining stock between 9' - 11' for a couple of years now and have had good luck using a circular saw and a straight edge to get the initial cut; the side I cut on depends on the shape of the wood, e.g., where I can best put the clamps.

Originally, I was just using a piece of 10' iron (and would have to move the piece if the wood was longer than say 9 1/2' or go to a 12' piece of wood). When I used the iron, I would have to use a couple of extras clamps as the iron would bend.

I have since starting to use the Smart Guide from Eurekazone with great success. I attacted a 4' section to the standard 8' section giving me 12'. If I were working with shorter boards, I would I usually use a table saw to straight out the other side. As these are so long, I use the Smart Guide to also straighten out the other side.

I, of course, do most of the things that the others mentioned such as cutting the piece shorter if too much of a bow and/or cup.

Regards, Joe

[Donnie Raines]

I've been joining stock between 9' - 11' for a couple of years now and have had good luck using a circular saw and a straight edge to get the initial cut; the side I cut on depends on the shape of the wood, e.g., where I can best put the clamps.

Originally, I was just using a piece of 10' iron (and would have to move the piece if the wood was longer than say 9 1/2' or go to a 12' piece of wood). When I used the iron, I would have to use a couple of extras clamps as the iron would bend.

I have since starting to use the Smart Guide from Eurekazone with great success. I attacted a 4' section to the standard 8' section giving me 12'. If I were working with shorter boards, I would I usually use a table saw to straight out the other side. As these are so long, I use the Smart Guide to also straighten out the other side.

I, of course, do most of the things that the others mentioned such as cutting the piece shorter if too much of a bow and/or cup.

Regards, Joe
Joe,

The concern is flattening the face of a board that has some "flaw" to it..be it cup or bow. Not so much the edge of the board.

Donnie Raines

[Todd Burch]

When a board is bowed so as when placed on face on the floor, it could be classified as a rocker for a chair (example is exaggerated for clarification), I pick another board if I need a long one, and save the bowed board for shorter needs. My explainantion above was for curved boards (faces are flat, edges are curved).

There are 3 (at least) gross classifications. Curved boards, bowed boards, cupped boards, and, well I guess there are 4 cases, warped or twisted boards. When I encounter warped or bowed board, they get cut up into shorter pieces, and I don't use the shorter pieces for critical parts either - like door frames. Cupped boards get resawn, edge jointed and glued back together (when I don't have a better board to finish the job) and are good for panels withing frames or face frames, and would be good for a glued up assembly, like a thick table leg. Curved boards, after edge jointing, if they aren't reactionary wood (meaning, when ripped, they don't curve again), are just as good as "normal" boards. Otherwise, they become face frame stock or secondary material (like a rear mounting cleat on a cabinet).

Pick your boards wisely for critical elements like door frames, table tops, longer lengths, etc. If it can be securely fastened to a larger structure, you can overcome a little curve or bow when fastening.

Warped or twisted boards planed thin are good for solid wood cabinet backs, or thin shelves in small cabinets.

[Chris Padilla]

Let's see: Cupped. Bowed. Twisted. Curved. Warped. Yes, I am all of these but I think a picture would be worth about a billion words here! :confused:

[Todd Burch]

Hummm... let's see if this works...

[Richard McComas]

Let's see: Cupped. Bowed. Twisted. Curved. Warped. Yes, I am all of these but I think a picture would be worth about a billion words here! :confused:


<img src="http://www.fototime.com/51BF02BB942D423/standard.jpg" border=0>

[Frank Pellow]

Hummm... let's see if this works...

That really "neat" Todd. And it's even useful.

[Frank Pellow]

Richard, I had not yet seen your drawings when I replied to Todd. Your stuff is usefyl too (even though it lacks the spiffy animation).

[Tim Sproul]

Todd,

Just a nit, but the term you are looking for rather than "curved" is crook. All boards that are warped are curved.

[Chris Padilla]

Thanks, Guys. Pictures are worth...well, you know! :)

[Todd Burch]

Thanks Tim.