Face Jointing Long Pieces

[firefighter ontheside]

I like to have really flat boards to make cabinet doors from.  Sometimes they are hard to face joint.  Today I'm trying to make some flat stock about 56" long.  In face jointing them I keep make thinner boards that are still bowed.  I think the issue is that I need a long infeed so I can hold onto the pieces at the ends or nearer the ends.  I'm going to cobble together an infeed support and see if I can get better results.  Does anyone have any other suggestion?

[Crusarius]

Sounds like you need a CNC slab flattener  I can deliver

I do think you have the right idea with the longer infeed and outfeed tables. I have never had any luck with a jointer. But my jointer is also a 4" cutter with about a 14" total table length.

[firefighter ontheside]

I should mention this is the first time using the new to me, but old jointer with new helical cutterhead.  As near as I can tell, it is dialed in and the tables are coplanar.  Maybe I should try a piece on my old jointer and see if I do any better.

[tule peak timber]

One of the tricks I use is to "sneak up" on dimensioning over a period of days or even weeks to get flat stable stock. The day of final dimension the panels go immediately into the build/ construction. This lets the wood relax and acclimate between machining and yields good flat results for me. These two panels are large like yours and I've been on them two weeks.

 

[tule peak timber]

Another trick on boards that are too long for the jointer is that I visually sight down the face and literally massage the twist or high spots out of the ends of the board. You have to hang on to avoid kickback, which would ruin your child bearing equipment and it probably violates other safety issues. But simply using a touch and feel approach, back and forth over the cutter head before a full pass works well. As earlier stated, don't try to do it all at once, particularly on large, long or wide boards. Sometimes, I estimate what I need to remove at the cutter head and use my finger tips against the end of the jointer bed as a shim. Again, touch, feel, experience. Don't misunderstand me, my hands are never, ever, near the cutter head. Safety, speed , time , money... ;D

[btulloh]

The outfeed table is the key to taking out twist or bow. It sets the resulting plane. Down pressure on the outfeed side as soon as there's enough surface on there. It can be tricky for sure. Agree with the above about small bites. Once a bit of the desired plane is achieved, keep all down pressure on that area of the piece being face planed.

Using a hand plane initially to establish the desired new plane can be very useful and quite a time saver. 

The main thind is to only put down pressure on the area where the desired plane has been established. Then as long as both tables are in parallel planes (infeed being lower than outfeed!) it'll produce a flat side. 

[Tom King]

That jointer is plenty long enough for those boards.  Start with the hump down.  Flatten a spot in the center of the hump, and try to hold the board on the plane that you want the straight side to end up.  

Don't take big bites.  Sight it after each pass, and see if it's going the way you want it to.  You may need to wedge it one way or the other by starting the thinner end of your flat spot on the outfeed table.

I'll see if I can find some pictures.  These 4x's were so twisted, and bowed that you could look at them and see three sides.

First picture is 16' piece I started with.  I needed two 8 footers, so cut it in half.  Pictures on jointer are of 8' pieces.  This is the same jointer you have.

Second picture is after 4 or 5 passes.  


 




 

With one side flat, that side is held against the fence to work on an adjacent side.

 


 



 

 

 

I used this because it was old and dry, and probably had done what moving it's going to do.  I made these handrails out of them.

A jointer doesn't automatically do the work for you simply by passing a board over it.  You have to have a starting strategy, sight it after each pass, and develop a strategy for the next pass.

[firefighter ontheside]

Thanks guys.  Great ideas.  I have used a hand plane in the past to take out some of the worst offending wood before I take it to the jointer.  Also, I have done a technique where I feed part of the one end about half way thru and then pick it up and feed that end again.  After that I will turn it around.  As Tom said, this jointer is long enough.  I know it is.  I think the problem is coming from this poplar.  If I push down in the middle at all I am able to spring the board down and take the bow out of it which of course is a problem.  

[Tom K]

That's one of the many reasons I wont use poplar for 5 piece doors, it flexes too much (along with being too soft).

Your jointer is plenty long. I do it to opposite of Mr. King. On that short of a piece I start with the hump up so I can keep decent pressure on each end. A couple light passes until it looks decent and then send it through the planer to see if it stays flat.

[firefighter ontheside]

I normally never joint with the hump down, but in this instance I think it might work.  The bow in 5' is only about 1/8" at most.  I think I can use my push pads in the middle and make sure that each end is up in the air about the same amount and keep making the flat spot bigger until the whole thing is a flat spot.

[Tom King]

That's exactly what I was trying to explain.  It can be done the other way too.  There is no one rule that says there's one way to do anything on a jointer.  With severe bow on longer pieces, for me it's easier to keep making the hump flatter and the flat larger.  

[DWyatt]

I always used to try running the pieces through frowning, taking a little off each end. The problem is that I 90% am using 4/4 material and I would push too hard and spring it and not flatten the board. Then a read a post/saw a video from @YellowHammer about running things through smile up. Set the board smile up on the jointer then place for push block as close to the middle of the board as possible (close to the end of the infeed table, splitting the difference of the bow or twist. Push through without moving the push block. This should give you a big flat spot in the middle. Repeat as necessary, always keeping the flat spot referenced to the bed. I can do 8' long 4/4 material this way on Dad's jointer which is similar to yours. 

[YellowHammer]

We have had a heck of a time face jointing and flattening long boards the conventional way, frown down, two hands, and it results in the same thing you are seeing.  I have played with different techniques for hours at a time, trying to figure out why conventional, two handed jointing techniques don't work exceptionally well, and it would take a while for me to describe it here, but it is a factor of a lot of things, including board spring back, flex, etc just like you are seeing.  There is an easier and faster way, and it works great with 4/4 poplar.

By far the most effective way is to do it is how @DWyatt describes, and it's exactly opposite of American Woodworker Magazine techniques, but we do literally thousands of boards a week using this technique and make them vacuum flat to the bed flat.  Put the your push block (studded with teeth) on the lowest part of the bow or twist with the ends jacked up off the bed in the smile up look.  There is no way to mistakenly flex the board or have it follow the bed, because the only part of the board touching the bed is the center, low part of the smile, and simply run it through and make a flat spot or skid mark. Do not move the push block and if you use two hands put both push blocks at the low point of the smile, as close together as possible.  The key is to get a single point of pressure to the bed as focused as possible on the lowest section of the smile to completely eliminate flex and bed curve effects. Then do out again, and you will have a vacuum flat to the bed board.  If you have a high enough hp motor and a quick adjust infeed, it's possible to take 1/4", yes 1/4" of bow out at a time in one pass.  Simply place the board smile up, press down with one push block, and use your other hand to drop the infeed until the cutter just kisses the jacked up leading edge. Then feed it through, pressing down only on the smile and the board will come out flat. 

Of course, you should alway make sure you bed is dead flat with no tail off or twist.  Use a long aluminum flat edge and a flashlight and when it is adjust perfectly, take the outfeed knob off and put it in a drawer.  It should never need to be readjusted again.  All the work is done with the infeed adjustment, and I may raise or lower the bed for every board or so it's a one pass and done.  Mine is a spring loaded quick adjust.   

[kantuckid]

Last winter into spring I jointed by hand, solo, on my 8" jointer ~ 3,000 BF of pine 2x6's by myself.
 Yes it's hard work. I used two roller stands, set up to allow the equal amounts of 10' and 14' pieces.
 It's simple basic work.
 I did one edge, then straightline ripped them on my TS, then T&G'd alternate edges. Lots of piling and pushing. The operation called for strategic planning to get all my pieces piled in the right spot with the edges on the best side for the next operation. I did all of one length before doing the other length. Do I get an award? 8) 

 As I recall, a few 14's became 10's to lessen the curve. 
My last time I made lots of T&G 2x6's I bought KD wood and skipped the jointer part but lumber prices told me I was going to saw this bunch myself. 

[firefighter ontheside]

Dwyatt, Yellowhammer, Tom I will be back in the shop Sunday and will be trying this.  Yellowhammer, I will run some screws thru one of my push blocks so that they just come thru the foam on them.  That should make some nice teeth to hold onto the board.  Likely the two pieces that I was failing to get flat will now be too thin to use.  Thanks guys.

Kantuckid you at least deserve a "job well done" and "better you than me".  That's a lot of work.

[Tom King]

Funny about taking the outfeed handwheel off. 

 Mine never had one.  I bought it from a school auction in 1975, and I always knew why they took it off with a class full of kids, but I never bothered to look for one.  That outfeed bed has never been adjusted as long as I've owned that particular jointer.

[firefighter ontheside]

I got home late afternoon yesterday and tried a piece with frown up.  I had mixed results.  Still ended up with a bow.  This morning I went out there to check table alignment and cutterhead alignment.  I edge jointed several boards with the fence set to the back of the head and with the fence at the front of the head.  In both positions I got straight edges.  I take that to mean the jointer is set up well.  I face jointed some pieces of harder and thicker wood and had good results.  This makes me happy that its not the jointer, its me.  I will keep at it.  No doubt I will get it right with the frown up method.  

With knives I would use the outfeed adjustment when installing new knives, but that's it.  With the helical head I can see never touching it again.

[doc henderson]

I think if there is tension in a long board, it may be releasing some as you shave the peak off the bottom of the frown smile. for an experiment, mark a long line on the edge and then try your face jointing.  see if the sideline is still straight when done.  if it is still strait, then it may be technique or set up, not movement in the board as you shave more fibers off the middle of one side and the ends of the other.  the latter will make the line curved if the board is moving.  

[firefighter ontheside]

That's a good idea Doc.

[firefighter ontheside]

Well, I didn't do Doc's straight line trick yet, but I did run another piece across with frown up and one push pad in the middle.  It was working as I went, but now the piece is frowned the other way.  Clearly the problem is in the wood.  I measured moisture and it's around 7%.  I can live with a little bow in doors, especially long doors, so I guess I will keep working with this method and see how it turns out.

[YellowHammer]

Do you mean "smile up".  The one push block technique works when the board is oriented like a smile, with the center down on the table and the ends up not touching the table, and the push block directly in the center low spot of the smile.  

If the wood was straight and flat off the facer, but has since bowed, I agree there is an issue with the wood.  

[tule peak timber]

when we build millwork that is 30-40 feet long and longer that needs to fit, I use materials that will hold face at those lengths. Just stating the obvious- use wood that works better in long lengths, or engineer/modify it until it does. Sorry, I have no experience with poplar.

[doc henderson]

Robert, such a positive attitude.  smile, not a frown!

[YellowHammer]

Dad gum right!  My overwhelmingly positive attitude, lack of ego, tolerance of others and smooth diplomacy are some of my best character traits!!  At least that's what I keep telling myself! :D :D :D

[firefighter ontheside]

A smile up while woodworking is the best policy I find