How good is good enough? Milling for glueup

[john schnyderite]

I've got some well documented issues getting long boards perfectly flat on my jointer. I'm thinking if they are at least pretty flat, I can try forcibly get them as even as I can during glue up, and worse comes to worse, put some hours of handplaning and sanding in to eventually get a flat top. I'm losing hope that I can tune this machine or my technique enough to get these boards perfectly flat-- so how close is close enough?

[Richard Shaefer]

consider using dominoes or biscuits to align your boards as you glue, which should help.
I've never had a table glue up that didn't require cleaning up with a jack and smooth planes.
there's a reason they make wide bed thickness sanders. ;)

[Al Launier]

When gluing I try to minimize excessive clamping pressure to overcome any out-of-flat condition as I feel that will add additional stresses that will try to relieve itself when the clamps are released, in addition to squeezing out too much glue in places. Edge gluing is obviously different than face gluing, in that edge gluing is not quite as strong as face gluing, and there will still be a tendency for stress relieving. So, as Richard mentioned above adding biscuits, or dowels (my preference), will add strength to the glue-up. Also battens under the table top, if attached, will further keep things together over time.
For me, if I couldn't get perfectly flat joints I'd try to decide what would be acceptable to me as a glue joint in terms of the resulting glue line. If unacceptable, then I'd locally plane the humps down. Over stressing the glue-up to begin with could add potential problems over the long term.

Forgot to mention that the use of cauls will keep the boards aligned during glue-ups.

[Rod Sheridan]

For edge gluing if the boards aren't perfectly flat, I run them through the shaper with a glue joint cutter, using a stock feeder.

The feeder makes sure the boards are flat when going through the cutter, and the wedge shape of the profile aligns the boards during clamping.

Now, obviously if the boards are very thick or way out, a feeder won't flatten them.

If your boards are that far out, you'll need to plane or scrape the assembly after gluing.

I normally just use a cabinet scraper or a scraping plane............Rod.

[John TenEyck]

Garbage in = garbage out. If your stock is out more than say 1/16" over 6' then I think you need to take another look at your jointer to see if the tables are parallel and that the outfeed table is set correctly with respect to the knives. Spend whatever time it takes to get flat stock; everything after will be easier.

John

More thoughts:

Is your stock at EMC with your shop? If it's not it will cup if you just face joint one side and don't plane the other side. You can accommodate a slight mismatch in MC with the EMC of your shop by face jointing one side, then planing the other side, then alternating sides until you get to your target thickness.

[glenn bradley]

Place holder . . .

Sorry guys. I had more to say than I wanted to say on a phone and I thought I would be right back . . .

I hate to see people become frustrated with a situation that seems to show no improvement despite our dedication. We've all been there on some facet of the craft at some point. I didn't see anyone asking if the OP was just setting himself up for failure; over-driving the machine's headlights, so to speak.

What size/model of jointer are we talking about here? If you are trying for 72" lengths of 8/4 on jointer with a 30" infeed and no additional support it is a non-starter as far as achieving well jointed stock is concerned. I have 40-odd inches of infeed which is plenty for most furniture parts but, I still find myself doing this often enough:

399080 . 399079

There are always things that will push the limits of your machines. The jointer is one of those machines that relies on a consistent feed path for proper operation. If you do not supply that you will get sub-optimal results.

As to your specific question, I always find it is safest to answer "if it is close enough for you, it is close enough". You are not required to make other people happy in this craft unless your income relies on it. :)

[Pat Barry]

For the way I work, I only do a rough flattening, if that, before glueup. Mote important for me to the edges to fit together properly. Do final flattening after glueup. Hand planes and ROS.

[Bradley Gray]

When gluing up long boards I usually have to tweak an edge or 2 with a hand plane:

First, do a dry clamp-up and mark any high spots.

I have good luck laying a low angle plane on it's side on a flat bench.

I slip a strip of 1/2" ply under the board that needs a trim and use the bench top as a shooting board.

[Al Launier]

Place holder

​Place holder ???

[Jim Becker]

​Place holder ???
He didn't have type to type a response and intends to come back to it...hopefully within the 24 hour edit window. :D

OP, some good advise already. "Perfectly flat" can be a challenge with any one board so as has been noted, you deal with that after you get your panel assembled, either by hand or, perhaps, with the help of a wide belt you can contract to use or put your panel through for final flattening. And even boards that are "perfectly flat" can move slightly between when you mill them and when you glue them up a few minutes or hours, or days later. 'Nature of the beast...

[Randy Heinemann]

I didn't see whether the jointer was being used to flatten both sides of the board? I doubt that you could get both sides flat enough by jointing them both rather than jointing the first side and using a planer to get the boards to the same thickness and flattening the other side in the process. This may not be the problem, but I didn't see a mention of a planer (other than hand planing) in the original post.

[Mike Cutler]

John

I truly do not mean to be a jerk, but something is amiss in your milling technique that needs to be corrected.
Your boards should come off the jointer one side flat,and one edge at 90 degrees to the flat, jointed, face. They will not be the same thickness, but they need to be flat on one side. Trying to pull boards into alignment is a major butt pain, and will just lead t other issues with the final glueup itself. You will fight that large panel the whole way. BTDT, but I think so has everyone else at one time.
Close enough for me is every board lying on a flat surface, and butted up against another board, has no gaps. The faces can have a little difference along the edge in height, maybe at most a 32nd, but I shoot for zero.
The wood will want to find a new equilibrium point and sometimes bowing can occur, but it really needs to be kept at minimum.
Once I am done milling the boards for a large panel, if I am not gluing them up immediately, I clamp them to each other, or the edge of the work bench, until I am ready to glue them up.

As I said earlier, I'm not trying to be a jerk, or nitpick what you're doing. Large panels are very difficult for the person working alone in the shop when the wood is cooperating. When it's not, then it can become a major butt pain.

[Bill Space]

I've got some well documented issues getting long boards perfectly flat on my jointer. I'm thinking if they are at least pretty flat, I can try forcibly get them as even as I can during glue up, and worse comes to worse, put some hours of handplaning and sanding in to eventually get a flat top. I'm losing hope that I can tune this machine or my technique enough to get these boards perfectly flat-- so how close is close enough?

It sounds like the OP is questioning why he cannot get his boards equally thick on his jointer.

If he is hand planing after glue up the issue is unlikely edge related, since he mentions hand planing after glue up to make the boards flat. So he most likely is wondering why he cannot get his boards off the jointer with parallel surfaces. It sounds like he does not have a planer.

Perhaps the OP could confirm if the issue is with the board edges, or the flat wider surfaces of the boards.

[Jim Andrew]

Cauls help to make a flat glue up. Mike Henderson did a great tutorial on using cauls.

[Simon MacGowen]

It sounds like the OP is questioning why he cannot get his boards equally thick on his jointer.

.

If he was wondering about that, he was missing a machine: the thickness planer. It is close to being impossible to produce equally thick boards using the jointer alone.

Simon

[Jeff Heath]

This might help

https://www.youtube.com/watch?v=94DDXOIeACA&t=42s

[stevo wis]

The technique that has worked well for me is to:


1. Joint the best face to 60-80% clear and flat. If twisted or overly out of flat, use scrub plane to hit high spots.
2. Plane the opposite side and on additional passes flip as needed to plane worse side.
3. if the glued up panel will fit in my planer, keep the individual pieces as thick as possible running all pieces through the planer together.
4. Joint the best edge, rip 1/16 over width as needed, then joint final edge.
5. Arrange for grain match, glue trying to keep width under planer max. I use a pair of cauls with all thread clamping them flat.
6. After glue dries, treat the glued up panels as an individual board and go to step 1, or just pass through planer if adequate, or hand plane to smooth out as needed. It's some work, but its enjoyable quiet work.

i know this sounds like a lot, but it goes quick.
I especially like the comment of jointing the edges with a handplane on side if needed.
Stevo

[Kevin Smira]

So, I have a friend that used to say that Dale Nish would tell him "If you don't have time to do it right, where will you find time to do it over?"

[Jeff Heath]

So, I have a friend that used to say that Dale Nish would tell him "If you don't have time to do it right, where will you find time to do it over?"

Very wise words, so rarely heeded.

[Robert Engel]

Generally I think its a bad idea to force boards into alignment not only because it introduces stress to the panel, but because inevitably it will leave glue lines. That said, depending on the width, the type of wood, and how off it is there are instances where I don't worry about it too much I just clamp and go. For example, clamping out a 1/8" gap in 3" wide softwood is much different then 9" wide hardwood.

I use hand planes to fine tune the joint. I get them as close as possible and usually create a spring joint by taking a few extra thou off the middle of the board.

We already had the debate about glueing a handplaned joint, didn't we? :rolleyes:

OOPS I think I misread your post. You're talking about the faces, right? Slight bows are not an issue. You can use alignment aids like biscuits or Dominoes, but I use clamp pressure and a rubber hammer. I'm always gluing a top up thick to give me room to fine tune.

Well it still boils down to making sure your edge jointing goes right.

[Jared Sankovich]

I think people are confusing edge flatness vs face flatness. I'm reading the OPs question as having some bow left after jointing (not edge crook or kink) which depending on the length of board is normal imho.

Dominos, biscuits, glue joints or cauls.
399184

[john schnyderite]

I have a delta DJ-20. I use a roller off the outfeed to help support the boards as the come off but that is more to keep the boards from falling off than to keep them parallel to the tables. I try to use hand pressure to keep the boards flat at the end of a run.

I've made a few recommendations to the machine based on what others have said, but results seem inconsistent. I was able to get several boards off pretty darn straight, and built a tabletop that came out great from it but other boards I'm just really having no luck. Maybe its technique, but I don't really have a teacher to show me what I'm doing wrong. I'm just a guy who had some fun in woodshop class back in high school and likes to work with his hands and build things. I realize as I go on, I'll get better at this craft, but I feel like holding this build up until I get things perfect is not going to help me as it feels like I'm just delaying and not really getting anywhere.


Place holder . . .

Sorry guys. I had more to say than I wanted to say on a phone and I thought I would be right back . . .

I hate to see people become frustrated with a situation that seems to show no improvement despite our dedication. We've all been there on some facet of the craft at some point. I didn't see anyone asking if the OP was just setting himself up for failure; over-driving the machine's headlights, so to speak.

What size/model of jointer are we talking about here? If you are trying for 72" lengths of 8/4 on jointer with a 30" infeed and no additional support it is a non-starter as far as achieving well jointed stock is concerned. I have 40-odd inches of infeed which is plenty for most furniture parts but, I still find myself doing this often enough:

399080 . 399079

There are always things that will push the limits of your machines. The jointer is one of those machines that relies on a consistent feed path for proper operation. If you do not supply that you will get sub-optimal results.

As to your specific question, I always find it is safest to answer "if it is close enough for you, it is close enough". You are not required to make other people happy in this craft unless your income relies on it. :)

[john schnyderite]

Sorry for the confusion,
I've got a planer. I was talking about getting 1 face perfectly flat prior to going to the jointer.

[Kevin Beitz]

If your boards are that far out use liquid nails.

[Frank Pratt]

Sorry for the confusion,
I've got a planer. I was talking about getting 1 face perfectly flat prior to going to the jointer.

Where are you located John? I ask just to be clear on terminology & what you are talking about. By planer, do you mean the machine that has the cutter head & feeder rollers overhead to push the board through? If so, then that is not the right tool to use 1st. The jointer is what is used to get 1 face flat, then the board is run through the planer with the flat side down. It will plane the top side flat & parallel to the bottom side.

You can do without a jointer by making a sled to run the board through the planer on, effectively using the planer as a jointer. You can Google how to do that, there are tons of videos on the subject.

[Jim Becker]

Frank, he was confirming he has both a jointer and a thickness planer. He's struggling with the flattening technique on the jointer.

[john schnyderite]

Bingo -- Jim's got it.

I've been keeping at it and getting better results putting less pressure on the boards as I feed them through. You can see a bit on light under a straight edge towards the end of most boards, but I rough cut them large enough that I should be able to make that waste area anyway. Thanks all for chiming in. Are there any NJ'ers on here? I'm wondering if there are any woodworking clubs or communities in my area where I can learn from others.




Frank, he was confirming he has both a jointer and a thickness planer. He's struggling with the flattening technique on the jointer.

[Jim Becker]

You actually shouldn't be putting "any" pressure on the boards when jointing that's not necessary to keep them on the table...as little pressure as you can get away with because you want to shave off the high spots. If you compress the board, you'll never get it flat and end up with a very wide toothpick. :)

[Mike Cutler]

John

Now I understand what is happening better.

I have a 6" Jet jointer and it has been used to joint boards 10+' long. Both edge and face. Your jointer is little bit wider, so definitely doable.

It's critical to be able to control that board coming off the back of the jointer, and controlling the tail end prior to hitting the in feed table. I have these two Rigid "Flip Top" stands that I use, and my table saw is at the same height as the jointer outfeed table, so that helps stabilize the material.
I did some really long pieces of 2" Jatoba that were wicked heavy and ended up throwing together two extension tables. You have to control that board all the way through the jointer. Long boards for a person alone are difficult.
I mark the face of the wood I am jointing with a pencil, so I can keep track of my progress. Mark, Joint, flip over, mark again.The pencil marks will show you where material is not being removed after each pass.
On boards that have a twist I'll flip the board end for end to take down the high corners, and then joint as normal. The is a limitation with shorter bed jointers that needs to be accommodated.
Do not press down on the board after it passes over the cutter head. Apply only enough pressure to keep it moving forward. The initial section of the leading edge, the board made contact with the cutter head, is your new reference. It's not uncommon to have only the first 6" and last 6" of a long board actually make contact with the cutter head on the initial pass. You mark with the pencil so that you can keep track of the material being removed. More and more should be removed from each end, moving toward the middle of the board.
You can put a board through a jointer convex, or concave, with or without twist, and be successful. Most people start with the board convex to the cutter head, but it doesn't have to, though it is easier.
One more issue you could be having is improperly dried wood. Sometimes wood will continue to move on you during the entire milling process, even in a time frame as short as between passes on a jointer, as it releases stress. This can be frustrating and lead you down the path, so to speak.
Use a pencil, or piece of chalk. ;)

[Curt Harms]

As Jim says, as little down pressure when face jointing as you can get by with. I use a 'shoe' with a heel to be able to push horizontally without pushing down. Pushing down while face jointing is like trying to flatten a board with a planer - you'll end up with a thinner but still bowed or twisted board. I also cut boards to rough length before flattening. I learned this lesson soon after getting a wide jointer. Started out with a bowed poplar (thank goodness) board. I got it flat over its 8' length but it was about 3/8" thick on the ends and 15/16" thick in the middle.:o The shorter the board the less that has to be removed to get one face flat. Of course if you're building an 8' table shorter boards are not an option. What's that saying, too soon old too late smart?

[Patrick Walsh]

Call me anal retentive but I like my stock as close to perfect as possible through every step of a glue up.

I tend to work my glue ups just under the width of my planer and jointer. This way after the first glue up I can take just a light pass on the jointer on two sides and the same through the planer and have two more perfect pieces to edge joint.

Normally when I’m done and partially due to having a perfectly flat surface to glue up on I end up with a work piece near finished that could be cleaned up with a simple smoothing plane, card scrapper, or a very very light and quick pass with a sander.

I find no sense in leaving boards with excessive twist or warp to them then doing any kind of acrobatics to put them clamps thus clapmming pressure into the piece that will just find it’s way out.

I have worked with guys that insist on just jointing and planing to good enough knowing the laminations will only be jointed and planed again. These dame guys would edge glue pieces with tear out thinking “it’s at the glue line you will never see it what’s it matter” clearly not understanding or caring that is younolane down to that tear out your gonna have a problem as it’s gonna show.

My opinion is as close to perfect as you can get is good enough. Take the time early and save the headaches later.

[Jacob Reverb]

Call me anal retentive, but I generally use a newish ripping blade on the TS before gluing up a tabletop.

[Stephen C Cunningham]

Thank you John for asking the question an all those that replied. I've been struggling a bit myself and appreciate all the advice here. I'll be putting the tips to practice tomorrow after the Christmas festivities die down.
Merry Christmas everyone!

[Darcy Warner]

I face, plane one side, straight line rip an edge, rip to width on rip saw and glue up. Everything is over thick, I can fly through glue up.

[Mike Cutler]

My opinion is as close to perfect as you can get is good enough. Take the time early and save the headaches later.

Yep, couldn't agree more. You might be able to mechanically pull a board into form, but it's always going to resist. That stress will go somewhere.