can't eliminate bow in quartersawn oak on the jointer

[Kent A Bathurst]

Similar to the handplane option:

Pull the cutterhead guard. Adjust the fence so all but a tiny bit of the blades will be covered by the board. Set for thin cut.

Hold the lead edge up in the air, with the tail on the infeed table.

Lower the board's center over the cutterhead - @ 1/4", you will not touch the head.

1 pass on the back half.

Flip end-for end, take another pass.

Rinse, repeat.

After you have jointed, say the first 2' and last 2', you have a 3' gap in the center that still needs to be dealt with.

The table length is your enemy. Assuming the tables are coplanar, and set for a thin cut, as noted above.

You need to get to the point where you have coplaner surfaces at the front and back ends, and part of boths of these sections is in contact with the tables at all times.

Also - the QSWO I buy is about as flat as you could ever expect. I would be using 5/4 over 7' if I needed to be sure of min 3/4" finished dim.

[David Nelson1]

Sounds to me like the outfeed table is low. Gotta agree with Rod

[glenn bradley]

So we're saying his machine went out of alignment between the 2 boards that were successful and the 4 that are not? Possible I suppose. more likely the degree of irregularity in the portion of the material that is unsupported. Proper jointing requires a consistent feed path.

Place you example board on the jointer concave side down like a bridge over troubled water. Use something to hold it there and step back so you can see the whole board and its relation to the plane of the infeed table. Is any of the board hanging lower than the plane of the infeed table? Bingo.

Roller stands, table extensions or whatever means you have can solve your feed path problem if it is present. I also cut parts to oversized length and width to minimize compounded error before miling. Do you need a 7 foot board? If not you are delaing with bow that you can reduce by reducing the length of the material.

[Ted Reischl]

For the life of me I am trying to figure out why he is face jointing a 3/4 inch board that is 7 foot long? Especially when he is going to be gluing up layers to over 2 inches? I would face plane the boards if need be, do the glue up and then see what is what.

Maybe I have not been reading this right?

[paul cottingham]

I think I would use a hand plane across the board (traversing) to get the ends true with the middle. It's easy and fast.

[Mel Fulks]

He is making a door, so cutting the material in half is not going to help ....unless it's for the dog. I think in the several long
threads on this subject that I have seen, a total of three of us have reported better results with convex side down. Makes
me think only three of us have ever tried it. I've won a few bets with it ," I bet I can make both sides a little straighter by
faceing ONE side". Not every board will do it ,but NONE will get worse. Often with concave side down the other side will
get MORE BOWED. That is easy to verify with a straight edge.

[Kent A Bathurst]

For the life of me I am trying to figure out why he is face jointing a 3/4 inch board that is 7 foot long? Especially when he is going to be gluing up layers to over 2 inches? I would face plane the boards if need be, do the glue up and then see what is what.

Maybe I have not been reading this right?

Yeah - I'm with you on that, but was trying to answer the narrow, specific issue raised. Plane the adjacent sides [4 faces total] Glue, clamp, see what's what.

..........a total of three of us have reported better results with convex side down. Makes me think only three of us have ever tried it........

Make that at least 4. I do it when there are extenuating circumstances - no other way out. But - I almost never have rough stock that is more than slightly bowed / twisted. It never makes it in the truck. The 7' deal is the kicker here, of course. 95%+ of my stuff is significantly shorter, so rought cut as first step - any bow vanishes at 40".

[Ted Reischl]

I just decided to do a little math!

The OP stated he was making door stiles that will be 2.25 thick. He also stated he is using 3 boards. So each board needs to be .75 thick. He is starting with 4/4 stock. Then he wants to mill at least 1/4 inch off one of them to remove "bow". I am thinking he is going to wind up with less than 2.25 after he is done milling up the three boards.

[J.R. Rutter]

He is making a door, so cutting the material in half is not going to help ....unless it's for the dog. I think in the several long
threads on this subject that I have seen, a total of three of us have reported better results with convex side down. Makes
me think only three of us have ever tried it. I've won a few bets with it ," I bet I can make both sides a little straighter by
faceing ONE side". Not every board will do it ,but NONE will get worse. Often with concave side down the other side will
get MORE BOWED. That is easy to verify with a straight edge.

I agree. Where I am, the core of a board is almost always drier than the skin. Remove the skin from the convex face and the drier layer that you just exposed will work to pull the board flatter. Sometimes, you can even simply plane the convex face and the board will flatten out. It won't necessarily stay that way over time as it re-acclimates, but long enough to do whatever you need to do that requires flat faces.

[Mel Fulks]

Thanks for the help,Kent. You will soon get your membership card and "secret decoder ring!" .....I'm waiving the box top
requirement! But seriously,it takes a lot to overcome thousands of magazine articles written by lawyers and insurance executives. And that tip about about just buying the good pieces is great ... If your buddy owns the lumber yard!

P.S. You too, J.R. !

[Kent A Bathurst]

And that tip about about just buying the good pieces is great ... If your buddy owns the lumber yard!

It turns out it ain't all that hard. I go to what I consider to be the top-notch place in Metro Atlanta.

When I first went there, I spent some time just chatting with the guys in the warehouse about what they have, how often it is restocked, all of that. Bought a few sticks - maybe 100 BF - they bring out the bundles for you to pick from.

I made sure to restack each bundle so it was tight and flat-stacked.

The second trip, I needed some QS material. I brought a flashlight and an LN LA block plane. Went to the office, and asked the guy if I could take some swipes to get good idea of the face grain, and the end grain. "I will treat it like I own it" and then I plopped the LN on the counter.

He smiled - "Have at it".

Out in the warehouse, explained it all to the guys, let them hold the LN - not kidding, I doubt any of them had seen one in the wild. Now they are giving me the bidness about being a big-money guy with the fancy tools. Good-natured ribbing.

So - now I is a actual knowledgeable craftsman dude - not the "2 short sticks of strange exotic stuff" newbies, and not the "1,000 BF whatever it looks like" interior trim guys.

They will respond to any reasonable request, and are great guys.

Best benefit: One trip, looking for some 5/4 and 8/4 QSWO, the units they had were pretty picked through. Told them I would have to wait for the next supply. They said "Hey - that's cool - we'll call you".

Few days later "We'll be receiving your QSWO tomorrow morning no later than 11 am."

They cut the mill-pack bands for me. First guy through the stock. Bought what I saw that I liked - more than I needed, but some solid inventory of good stuff - good ray fleck, vertical end-grain, and flat-flat-flat.

If you are not a jerk, if you are a knowledgable guy, not a guy that only looks for bits and pieces for jewlery boxes [nothing wrong with that, of course - just an upside down customer service-to-sale ratio], you can get into their world, and benefit from the relationship.

[Jim Matthews]

Outriggers or extension tables may help.

IMG_20130926_103303.jpg

[lowell holmes]

If you will rip the bowed door into halves and then dowel and glue them back together with the bow in the halves opposing each other, you will get a straight door.

Since the halves are from the same board, the glue joint will pretty much disappear. The door I made like this 30 years back is still straight.

[Kevin Jenness]

I still don't know what the original poster's intent is. Perhaps he will post again and explain just what it is he is attempting to do with six 4/4, 6" wide boards to make stiles for an entry door and two sidelights. I and others are making an assumption that he is aiming for a three ply 2 1/4" lamination, which is not a bad plan, but perhaps not his. It would seem that he needs more material to make an entry with sidelights of traditional proportions. If so, perhaps he can come up with some flatter stock for the door stiles and use the bowed stuff for the sidelights which can be held in place by stops. I will say that gluing boards with opposing curves together and expecting to come up with a flat door stile long term is a crapshoot, and if I did I would let the lamination sit for as long as I could prior to finally flattening it and incorporating it into a door that should outlast me.

[lowell holmes]

The other approach in my mind is to start with 8/4 or 10/4 quarter sawn stock and mill it flat. If your making an entrance door, you have to use quality materials .