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Phyberoptic 02-25-2017 08:11 PM

Jointing long boards
 
I'm creating a Bar top from old growth pine boards slabbed to 2" thickness. Each of three boards to be joined is 11" average width and 12' long. I'll need 11' final length for the bar top. The middle board was ripped lenghwise into two boards. Both were edge jointed on my 7" jointer and then thickness planned so I had two 5.25" boards to glue up for my middle section. I used the 4ft aluminum straight edge to check the jointing results and as I move down the length of the boards there is only slight gap at the midpoint (looks like 1/32"), but when I put the boards together to see what the glue up will be there is 1/4"+ gap at the midpoint. With 2" think boards that's more clamping pressure than I want to introduce.

I've never jointed 12' long boards before on the jointer and the 6' long boards that I do all come out appearing dead flat. Even the 8' table I did last year came off that jointer near perfectly flat. So I don't get what's going on here.

I took a couple of hours to go through the jointer setup, the tables are co-planar within a few thousands, (i did add a shim to the outfeed table to bring it closer from where it had been). I've set the blade dead even with the outfeed table, and the infeed table is dropped 1/16" below the blade/outfeed.

Putting the boards back through the jointer for three passes each has not improved the gap at midpoint between the two boards that I can see as it is still about 1/4"

Any ideas on what I'm doing wrong? Am I just asking too much from the old jointer I have? The total length of the jointer tables are just under 4'.

Steve Neul 02-25-2017 08:42 PM

1 Attachment(s)
What you will need to do is put a catch table behind your jointer that is low on the front and have the back end of it level with your rear table. This will enable you to joint longer wood than you can with the jointer alone. Since it has a gap in the middle look down the edges of the boards and see where the boards are not straight. If it's a continuous dip in the middle start in the middle of the board and joint to the end removing wood from the end. Then turn the board around and start in the middle and do the same thing. Then look and see if it's any straighter. 1/4" you will have to do this more than once if not both boards.

For a long time I used this little 3' long jointer which I made an extension in order for me to joint 8' lumber. It's basically the same as the catch table only it's attached. In your case the catch table would need to be farther back.

Phyberoptic 02-25-2017 09:04 PM

Thanks, I'll give that a try in the morning... So the catch table is not co-planar with the outfeed table of the jointer. How much of an angle is this catchfeed table set at?
-=Phyber

Steve Neul 02-25-2017 10:36 PM

Quote:

Originally Posted by Phyberoptic (Post 1591113)
Thanks, I'll give that a try in the morning... So the catch table is not co-planar with the outfeed table of the jointer. How much of an angle is this catchfeed table set at?
-=Phyber

If you have the catch table flat and level with the rear table of the jointer more than likely the board will catch on the front of the table and push the table. I would put the front edge of the catch table about an inch below the rear table. It's the back edge that will do the job for you. The board should mostly pass over the catch table and make contact at the end of the table.

There is just too much gravity and leverage to try to hold a long board down on a jointer. By using the catch table it's like having a lot longer jointer.

EdS 02-26-2017 01:30 PM

You could solve the problem with a simple jig like this.
http://images.woodmagazine.mdpcdn.co...amp=1466456062

evilboweivel 02-22-2019 05:09 PM

evilboweivel
 
I have a 8' long extension on the outfeed side of my jointer most of the time and add a 6 1/2' to the infeed when first processing lumber. trying to eliminate the problem you are having

Larry42 02-22-2019 05:44 PM

The table saw trick will give you much better results. A sawn edge is perfect for gluing. Standard industrial practice.
It is really hard to produce a perfect jointed edge on a short jointer and a long board. How fast you feed, how hard you push down and toward the fence all affect the result. I've got a 16"x8' jointer that I've had Blanchard ground and use a fixture to sharpen the knives in place. Tables have been aligned using and 8' precision ground steel straight edge. But I don't use it for edge jointing, only for facing. I use a straight line rip saw for all edge gluing.
There is a good alternative for joining shorter work maybe up to 8'. Use a hand plane and a shooting board.

canarywood1 02-22-2019 07:16 PM

I concur with Larry 42, i do all edge gluing this way with a woodworker II blade on the saw.

woodnthings 02-22-2019 08:26 PM

I have a simple rule .....
 
The rule is ... When the workpiece is long, large or heavy, move the saw on or across the material. When the workpiece is small or short move "it" across or into the saw blade.


So, to get a straight, flat edge on a plank, I would use a circular saw and a straight edge clamped along the length as I have done countless times to break down plywood into smaller widths.

Having said that. I have made a board straightening jig for pieces 8 ft long and less:
https://www.woodworkingtalk.com/f27/...ble-saw-16999/


https://www.woodworkingtalk.com/f2/s...ig-used-29290/


https://www.woodworkingtalk.com/atta...d-100_1836.jpg


https://www.woodworkingtalk.com/f27/...jointer-12927/
You can also attach a long straight rail to the far side of you board to run against the fence like this:
https://www.woodworkingtalk.com/atta...r-100_1242.jpg

35015 02-22-2019 10:58 PM

Hello Phyberoptic,

I concur with some of the folks here...use a saw...

Those are some big long planks...Very typical of a days work in my field, with today being no exception as I worked on 23' foot plank and beam all day...

When "material" get "BIG"...move the tool...not the material most often!!!...or better yet (LOL) use hand tools...(but that's just my bias...LOL)

The shop I work in has a tool we call the "Aircraft Carrier!"...It's the 1942 24" wide and 8' long Oliver jointer...!!!

Do you know how we "joint" plank 90% of the time...!!!...It ain't with that tool but the 18" Northfield table saw...which does a better job...or... a rail saw which does and EXCELLENT job jointing...

Food for though!

Good Luck!!

j

woodnthings 02-23-2019 07:56 AM

You all but quoted my reply above ....
 
I have a simple rule .....
The rule is ... When the workpiece is long, large or heavy, move the saw on or across the material. When the workpiece is small or short move "it" across or into the saw blade.






Quote:

Originally Posted by Jay C. White Cloud (Post 2040027)
Hello Phyberoptic,

I concur with some of the folks here...use a saw...

Those are some big long planks...Very typical of a days work in my field, with today being no exception as I worked on 23' foot plank and beam all day...

When "material" get "BIG"...move the tool...not the material most often!!!...or better yet (LOL) use hand tools...(but that's just my bias...LOL)

The shop I work in has a tool we call the "Aircraft Carrier!"...It's the 1942 24" wide and 8' long Oliver jointer...!!!

Do you know how we "joint" plank 90% of the time...!!!...It ain't with that tool but the 18" Northfield table saw...which does a better job...or... a rail saw which does and EXCELLENT job jointing...

Food for though!

Good Luck!!

j


Jay,

I provided several examples and photos of the process I used in my reply. I would be helpful if you did the same as your procedure may offer additional "tricks of the trade", based on all your years of experience AND the huge machines you mentioned, 18" Northfield and a "rail saw" ...... we love photos! :vs_cool:

Maintenance Man 02-23-2019 12:02 PM

Track saw might be an option...

Echo415 02-23-2019 03:55 PM

Quote:

Originally Posted by Maintenance Man (Post 2040101)
Track saw might be an option...

A possibility but that is assuming the OP has a track saw. A similar but better option would be to go to your local steel supplier and buy a piece of straight angle iron that is a little over 12' and use that as a guide with a circular saw. I like angle iron because it gives room to clamp and the CC will have no problem leaving an edge worthy of glue if the blade is sharp(and assuming the OP has a CC)

35015 02-23-2019 07:08 PM

Quote:

Originally Posted by woodnthings (Post 2040053)
...I provided several examples and photos of the process I used in my reply. I would be helpful if you did the same as your procedure may offer additional "tricks of the trade", based on all your years of experience AND the huge machines you mentioned, 18" Northfield and a "rail saw" ...... we love photos! :vs_cool:

Thanks for the feedback Woodnthings...I usually do when others haven't already...Nor do I think :vs_worry: the OP owns Mafell or Festool rail based tools...So I think just mentioning a "rail saw" would lead them in that direction if they wish to possibly try it...

As for "pictures" of tools and shop, I don't do that when the tools don't belong to me personally but are "shop tools" collectively. That's part of the reason I have never posted in "what did you do today" or "show us your shop." I share my space with others, and we have all suffered some rather significant losses in our careers from theft. I personally have lost over $50K and will not ever allow that to happen again if I can help it at all!!! I would also share that many (most?) of my clients are rather exclusive and privacy is paramount to not only their personal lives but my professional bearing...

When I can post more details about something, I always do, and my "name" in quotes in "google images" displays quite a bit if every interested...

Thanks again for the feedback...:vs_cool::vs_cool::vs_cool:

olehunter234 02-23-2019 08:42 PM

if you ever want to edge glue native red cedar it should not go across a jointer. it will pull the knots . a nice sharp table saw and edge striatning jig will make a great glue joint.

woodnthings 02-23-2019 11:14 PM

the longer the better ........
 
In the case of jointer beds, longer is better, in fact, a 6 ft infeed and outfeed bed would be perfect. The closest I've come to that is this:
Using 2 Harbor Freight support rollers with adjustable height,
remove the rollers and replace them with a 2" x 12" plank on either side of the table.. . To remove the rollers from the stands just push in on the pin, it's spring loaded, and the roller will pop out. Bevel the edge of the plank to avoid the work hanging up on it. The height is easily adjustable on these stands.
https://www.woodworkingtalk.com/atta...p-100_1314.jpg https://www.woodworkingtalk.com/atta...p-100_1315.jpg


You can level out the plank to the outfeed table with a an 8 ft straight edge. It must be level because any variation will cause the cutterhead to remove too much material or skip it entirely. The plank does a better job supporting the work because there is no gap to bridge. You can bump it right up to the end of the outfeed table. :vs_cool:

Steve Neul 02-24-2019 09:49 AM

I've always wanted to build a machine that was like a cross between a bandsaw mill and a jointer where the board is clamped down flat and you draw the jointer head across the edge of the wood. It wouldn't be that difficult to make except for space to set it up. If I jointed long wood frequently I would be more likely to do try it.

fareastern 02-25-2019 03:59 AM

How about a No 7 plane and a good straight edge?Reading the original post I have doubts about whether the machine in question will ever be accurate without a major rebuild.If you have a 1/32 gap on each board over a 4 foot length it follows that you would have a 1/16 gap by putting those two pieces together at 4 feet long.Extend the length to 11 feet and it gets very much worse I suppose it wouldn't be that hard to calculate the radius that such a chordal deviation would define but for this project it is clearly excessive.


To try using a saw for the job requires that the wood is supported and that the wood is thick enough that any splintering can be cleaned up later-not that I would be in a rush to plane off the depth of the splintering.You might have to find a tame owner of a drum sander for that.


Making a straight edge long enough to span the boards and using it in conjunction with a pair of them to achieve verification that all three are good is a useful skill to have and a sharp plane used for a morning should bet you a lot closer than you are at present.

TimPa 02-25-2019 10:02 AM

OP when you have jointed the edges of 2 boards as you have, and you don't have the straight edge with the needed length to determine where the error is, try a string stretched taught to help see. a string won't lie...


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