# Jointing long boards with a bow



## mspain77 (Mar 26, 2016)

Hey guys,
I'm milling my Doug Fir 2×4's for a Jay Bates inspired table top and I'm having a heck of a time getting them flat. My jointer is dialed in now (thanks to all of your help) since I got the Snap-Check and got my blades to within .002 of the outfeed table.
The boards are rough cut to about 59" in length, and my 6" bench jointer has a 30" overall table length. I have two roller stands that I set up on both sides of the jointer to help keep the board as flat as possible across the table. I used a long straight edge to make sure both roller stands were on the same plane as both tables. The straight edge stands flat on each table while being supported by the roller stand on that side. I hope this gives a good visual as to what I'm working with.
I'm concerned about taking too many passes to try to wear down the high spots. My depth of cut is set at 1/32" right now. It seems like I hear the same amount of material being cut away throughout the length of the board, and I am putting ZERO downward pressure on the boards. I'm letting their own weight bring them down over the cutter head.
Has anybody else ever tried milling down dimensional lumber like this? Is it normal if I need to make 25-30 passes, or does that mean there's something I could've done differently to get there quicker? Please let me know what you think. Thanks guys.


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## WhyMe (Feb 15, 2014)

I straighten out long boards by double face taping on a straight edge and rip cut it on a table saw. Then clean it up on the jointer.


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## JohnDon (Mar 14, 2015)

Yeah, I've gone through the process of flattening 2×4's. There's a reason they're called construction grade! You just have to accept the fact that unless you're really lucky, you're going to lose a bunch of board thickness in getting construction lumber flat and straight. Just to clarify the specific warp that your board(s) has, I assume that by "bow" you mean the curve as in the attached diagram









While WhyMe's suggestion is good for a crooked or kinked board, I think it's hard to do with a bowed board. If you indeed have a bow, in my experience, FWIW, using a jointer is the best way of straightening it. You'll get it straight more efficiently if you orient the board on the jointer convex side up (that is, the leading and tail ends of the board are in contact with the bed- and cut first, and the gap is in the middle (cut last). While a longer jointer bed would make it easier, you go with what you have, and with your setup you should be able to get good results.

Depending on how out of whack the board is at first, it can take a lot of passes to straighten. You mentioned that by sound is seems that you're removing the same amount of wood along the entire length. An easy way to check on where the jointer is cutting is to make cross hatches on the board surface with chalk, and see where the chalk is removed after jointing. Good luck!


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## Ger21 (Oct 29, 2009)

30 passes at 1/32 is 1 inch?

If the cutterhead is removing material the full length of the board, it should be flat. 
You want to apply pressure over the outfeed table after the board passes the cutterhead, provided it's actually cutting.


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## JBrow (Nov 18, 2015)

mspain77,

I have run 4/4 stock across a 36" Craftsman jointer up to 60" long with a feed roller even with the outfeed table. I get the board flat enough to run through the planer to produce flat stock having made no more than 10 light jointer passes. Occasionally, I remove too much material but mostly end up with stock that can be ultimately milled flat to ¾". Some of these bad results are due to poor technique while other bad results are from trying to use lumber too far from flat.

From the sounds of your setup, you should be able to get a flat face in less than 30 passes; yet your post suggests you are not getting this result. I assume that you are paying close attention to the board as it is run across the jointer to ensure that it is not rocking or shifting as it is face jointed. With your set-up and if the lumber does not shift or rock as it is jointed, then perhaps it is flat but the means by which you determine flatness is failing.

There are some additional things that could be tried. The first is to only face joint the lumber until it sets flat. There could still be some areas on the jointed face that have not been cut, but the board will rest on both straight edges along the length of both edges without rocking. With stock over 1" thick, I think that planning the unjointed face first with the partially jointed, but setting flat, face down will make the unjointed, but planned face flat. Running the freshly planned flat face down through the planer would clean up the partially flatten face.

The second idea is to mark the face that is to be jointer. The pencil marks on the face will be progressively cut away as the face nears flat. Pencil marks left on the face after running the board across the jointer indicate areas that have not been cut. When all the pencil marks on both edges are removed, it is ready for the planer.

That last suggestion is to run a cupped board across the jointer with the crown up. If the board has a twist, run whichever face sets flatter across the jointer.


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## bruc101 (Sep 13, 2008)

I straight line all my boards on the table saw, especially long boards for table, cabinet and island tops. I have several length and width jigs to get the job done for me.

You can see one of my straight lining jigs here.

http://lumberjocks.com/projects/63970


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## mspain77 (Mar 26, 2016)

Thanks for all the input guys! I feel I need to clarify what I've got going on. The board definitely has a bow, and it's maybe 1/2" from end to end if you were to measure the dip in the middle with a straight edge along the length of the board. Secondly, it IS getting better, and I haven't made 30 passes yet. I've made about 9 or 10, but I was being proactive with this question because I feel it may take 15 or 20, and that seems excessive to me. When I run it at any more than 1/32" depth, I get some chattering. Idk if that's because of the type of wood or what causes that. I've slowed down when that happens, and it helps a bit, but it still seems to chatter at the same parts of the board. I just dialed in my knives with a Snap-Check to within .002 on all sides, and triple checked that so I'm sure my knives are not the issue with the chattering.
The marking along the face to see where I'm taking material off is a great idea, and though I've seen that on YouTube, it escaped me for some reason, so I will definitely do that tomorrow. Idk if you guys are familiar with Jay Bates on YouTube (Jay's Custom Creations), but he make some amazing things with dimensional lumber, and seems to pass his boards on the jointer 2-3 times max (though his huge Grizzly jointer is much nicer than mine). I was extremely particular when selecting my boards. I chose all the quarter-sawn boards, and I ripped that lumber stack up getting them. I put it back nice and neat though.
Well I think I covered all that stood out to me in all of your responses, and I appreciate the heck out of you guys chiming in. Please keep it coming. After all, I'm new to this, and I would love to keep learning from some of you veterans as much as I can.


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## Unknowncraftsman (Jun 23, 2013)

I'm thinking that if your confidant in your technique then your set up is off. Setting up outfeed rollers on short jointer beds is fussy to get great results.
Are you able to produce two edge jointed boards with the machine without the extensions?
Even something 3 ft long would be a good way to test.
Everything about a jointer is how flat the tables are and coplane.


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## Ger21 (Oct 29, 2009)

If you're face gluing these together, I would not joint them first. Run them through the planer to clean up the faces, and then glue them up in groups of 3, preferably clamping to something fairly straight and flat. Once the glue-ups are dry, then run them on the jointer. You'll be working with much flatter, and more stable material, and not jointing away half of your wood.


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## rwe2156 (May 7, 2014)

What's your finished dimension?

A 1/2" bow in a 59" board = unusable wood or cut it shorter and use for something else. You'll be down to a 3/4" thick board before you know it. Keep in mind this amount of bow is probably stress in the wood, not moisture related and is very likely to re-bow by the next day.

A word of advice: If you're taking a lot of wood off one side trying to joint it, you will almost always end up with a re-bow because of unbalanced moisture.


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## Nubsnstubs (Aug 30, 2013)

A 1/2" bow in a piece of wood 59" is a slight problem, but not as bad as some have mentioned. The op is going to glue this wood to other pieces of wood to make a table top.A good flat glue table, a bunch of clamps, glue and a hammer is all that is needed to straighten any wood, except cupped boards. Twisted wood can be glued if you know how to correct while in the clamps. As long as the edges are equal, even with a bow, 3 pieces will straighten any wood if the glue holds like it is supposed to. Just do it, and show the finished product when done.

Too many people agonize over non existent problems. ........... Jerry (in Tucson)


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## MadMark (Jun 3, 2014)

Use a wood other than fir. Its stringy an leaks sap. Yecch.

M


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## WhyMe (Feb 15, 2014)

Referencing the picture of bow vs crook the use of straight edge and ripping on table saw was for crooked boards.


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## mspain77 (Mar 26, 2016)

I've reached out to others that make nice stuff out of dimensional lumber and they said Doug Fir would work, so that's what I'm going with. I will be joining the boards together on the edges; probably 5 or 6 across depending on what my final dimensions are. I'm jointing one face and one edge to have a flat reference surface so that once I get all 6 done, I can send them through my 12.5" planer to equalize the size based on the smallest board I have at that time. That's why I want them all done now. I can still glue up in 2 or 3 smaller batches and them glue those up but I'll tackle that when I come to it. For now, I just want to get one face and one edge flat so I can plane them all down, then rip the last edge on my TS and glue them up right away.


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## rwe2156 (May 7, 2014)

> Use a wood other than fir. Its stringy an leaks sap. Yecch.
> 
> M
> 
> - MadMark


B.S. (broad strokes)


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## jdh122 (Sep 8, 2010)

You probably know that you need to run the concave side through the jointer and not the convex side, but just in case: if you run through on the convex side it's easy to simply keep buzzing off wood without making much of a dent in the bow.


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## mspain77 (Mar 26, 2016)

Okay guys, problem update:

So it appears that the slight bow (on the face of the board) IS a product of my technique or set up or something. I'm getting smooth edges but when I placed the boards next to each other, I noticed that the ends were flush with a small gap in the middle (so now I am creating a crook as well). When I turned the boards around, same thing. Flipped each one over and then both…same thing. I measured the board width at all ends and I have 3 1/4" on one end, 3 3/16" on the other end and just under 3 1/16th in the middle. It seems that somehow the board is heaviest over the cutter head when in the middle of the cut.

I set up the roller stand using a long straight edge to where the straight edge was flush on the table top and would run over the roller perfectly without lifting the straight edge or dipping it. That way the roller stand doesn't elevate the board and force the trailing end into the cutter head more, nor does the board dip to meet the roller and thereby pull the trailing end up and away from the cutter head (in theory).

I noticed that when the board is centered on the table and the middle is over the cutter head, that's one of the rare times that the board is not in contact with a roller stand on either side. I'm confused as heck right now. I only started using the roller stands because the boards' weight was lifting the ends from the cutter head and I wasn't

















I'm not sure how this is happening or what I need to do. Additional pressure at the beginning and end of the cut? How would I regulate that?? Please help.

getting even cuts in the first place, and now it seems I'm getting the same thing but it feels much safer.


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## Nubsnstubs (Aug 30, 2013)

I only use the jointer to clean up one edge. After cleaning it up, I then take it to my saw and rip it jast about 1/16 wider than needed. After ripping it with the jointed side up against the fence, I then turn it around and set the saw for the dimension I need. I rip the board/boards and now all are parallel. If you use a jointer for sizing you lumber, you are begging for frustration, and it looks like you just found it….....

Are you just going to clamp and glue, or are you going to use dowels, biscuits, or other methods of aligning the boards? ............. Jerry (in Tucson)


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## pintodeluxe (Sep 12, 2010)

1+ jointing boards concave side down. This gives you two points of contact. Otherwise the board may never get flat.

If it's twisted, focus on keeping the leading edge flat and not letting it rock. If it is allowed to rock back and forth, you will be chasing flat until your board is just sawdust.

One of the main issues is the length of the jointer beds. I used to have a 6" jointer with roller supports at either end. Due to uneven floors, and the fact that some roller supports have some play in the roller assembly, makes this technique very difficult. I switched to a 8" jointer with 76" beds and it is like night and day.

The very warped boards may just need to be used for shorter workpieces.

Good luck with it.


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## JohnDon (Mar 14, 2015)

+1 on Jerry's comments about ripping on the table saw. Not only will you end up with the width you want, but the edges will be parallel (which you can't assume with a jointer).

One thought that occurs to me. Have you checked to make sure your infeed and outfeed tables are coplanar? If there is any slop in the ways, the weight of long boards could force the bed ends to sag, and can result in the cuts you're getting. Raise the infeed table to the level of the outfeed, and check with a long straightedge for any tilt.

BTW, that's some nice looking DF. I wouldn't worry any any sap leaking, and I assume you're going to put some finish on it anyway. Good luck.


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## AlaskaGuy (Jan 29, 2012)

At this point I have to agree with the guys who suggest using the table saw. If you can come up with a decent straight edge to build a jig with.

I'm lucky enough to have a sliding table saw so I use my jointer mostly for face jointing and straight line of the slider.


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## davezedlee (Feb 22, 2016)

"got my blades to within .002 of the outfeed table."

maybe this could be the source of your problem… if your knives are low, they could very easily create a bow across a 59" length

i think all jointers need to be set independently, but dead-level to the outfeed table (and later, 0.001" higher) might be a better starting point

using the "scrape a straight edge" (but not moving it) should get you level; moving it by 1/8" would get you slightly higher

YMMV


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## Unknowncraftsman (Jun 23, 2013)

I think a small gap in the middle is not a bad thing at all.If you can close the gap of two boards with your hands perfect! And that's exactly what I would expect from trying to machine wood that's too long for the machines beds.
As for convex up or down doesn't really matter when you have a jointer with long beds.
You picked some nice looking Dougfir.


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## AlaskaGuy (Jan 29, 2012)

> Use a wood other than fir. Its stringy an leaks sap. Yecch.
> 
> M
> 
> - MadMark


MadMark, How does this help answer the OP's question?


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## mspain77 (Mar 26, 2016)

@Aj2: Thank you.

@davezedlee: I originally followed an article in wood magazine about setting the knives higher and moving a scrap of MDF 1/8", and I got absolutely horrible results. The Wood Whisperer did a video on setting jointer knives and said that .002" above the out feed table is ideal. I can't complain about the actual cuts I'm getting now; I'm sure it's just a set up problem with these long boards. I don't want to change my knives to accommodate long boards which I would rarely try to joint when I get amazing results with regular length stock.

@JohnDon: Yes, I checked and my tables are coplanar.

@Nubsnstubs: I'm not attempting to size the boards with my jointer. I just want a flat edge for the glue ups, and I will size all the boards in my planer once I get that flat edge and face. As far as the glue up, no biscuits, dowels, dominoes or anything else. I got an email from Jay Bates suggesting that I plane 2 flat identically sized boards, put wax paper on them, and use those to rest the table top boards on. As long as the two boards on bottom are flat and sized right, and I ran all the top boards through the planer I shouldn't have a problem. I'm going to do that along with something I saw from the Samurai Carpenter about putting a little tension on the boards with a clamp during glue up and going through by hand and flushing up all of the edges. That should produce no more than 1/32" anywhere which I can easily sand down.


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## davezedlee (Feb 22, 2016)

i only mentioned the "dead-level" setting because i, too, set my knives originally according to different recommendations… setting .001" high gave me .001" snipe, .002" high gave .002" snipe, and .0015" low (manufacturer's instructions) left me with tapers

dead level fixed it for me, in this case


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## AlaskaGuy (Jan 29, 2012)

This is a pretty good way to set you out-feed table in relation to your knives.

http://woodworkerszone.com/wiki/index.php?title=Setting_jointer_outfeed_table


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## Tony_S (Dec 16, 2009)

> This is a pretty good way to set you out-feed table in relation to your knives.
> 
> http://woodworkerszone.com/wiki/index.php?title=Setting_jointer_outfeed_table
> 
> - AlaskaGuy


Quick and simple…
It doesn't need to be any more difficult than that.


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