Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.

Any advice would be appreciated...
Thanks,
Ken

ken blais wrote:
Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.

Any advice would be appreciated...
Thanks,
Ken

One thing that I thought of was are you pushing down on the boards as
they go through or just making sure they're against the fence....at
1.25 I wouldn't think you could bow them down....But you might be a
mighty strappin lad....

When you push in the middle there might be just enough flex to cause
the extra bite out of the middle section...

Just my 2 pennies worth...

ken blais wrote:
I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends.

Is your outfeed table maybe slightly too low?

Also a little bit of this is okay, as it gives you a "spring joint".
For more information, see about a third down this page:

http://www.taunton.com/finewoodworking/pages/bw0002.asp

Chris

That flex that Bremen68 talks about could work to your advantage. These
are long pieces that'll probably clamp together just fine, as long as
you've got a nice square edge to glue up. If you really want/need a
good edge jointing, you'll have to "extend" your tables with roller
supports or somesuch. And their height must be set _very_ well. Tom

Chris Friesen wrote:

ken blais wrote:
I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends.

Is your outfeed table maybe slightly too low?

Too low shows up w/ some snipe at the ends...

Also a little bit of this is okay, as it gives you a "spring joint".

Don't disagree here too much as long as it's not excessive...

A 22" exit table is pretty short for a 7' long piece. I suspect a lot
of it has to do w/ not being able to hold the ends down as firmly when
entering/exiting the cutting area as compared to the middle section.

It is virtually impossible to add and extra infeed/outfeed table to a
jointer a _precisely enough_ the right height to be useful.

I'd suggest the expedient of taking one of two paths although the
jointer set up should be carefully checked for accuracy first by
jointing a 4-ft or so piece and testing that you get a good fit
there--if not, tune until you do. After that preliminary step, I do one
(or both) of the following for pieces longer than I can handle easily
(altho w/ an 8" longbed it's relatively easy to do 7' as long as they
pieces are _too_ heavy)...

1. Set the jointer for a whisker-thin cut and start in the middle and go
each way to take the concavity out. If the setting is thin enough, the
will be no ridge/hollow in the middle

2. Use the jointer for the first rough pass then a sharp hand plane to
fine tune the fit. About two or three strokes should do the trick.

Not making a comment on technique, but if you are using plain old
dimensional from your lumberyard, a proper jointing is the lease of
your problems. When those boards properly dry out, it is unlikely that
they will remain very strainght very long.

ken blais wrote:
Hi...I'm trying to edge joint some 7 foot boards so I can glue up a
slab for a bartop i'm making for my garage. The boards are 1 1/4
thick and are douglas fir (i used 2x6s from the local lumberyard).
I'm having trouble getting a straight edge, it seems the more i joint
the same edge, the more concave it gets. It's very slight but it
seems the jointer is taking more off the middle of the board than the
ends. I'm using a Yorkcraft jointer, 6", 22" infeed table, 22 1/2"
outfeed table. I haven't had this problem with smaller boards, and
i'm not sure if it's my technique, or a machine setup thing.

Any advice would be appreciated...

Long boards need long table. Make it simple...use the factory edge off
a sheet of ply as a guide and rout the edges.

--
dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

jointing 7 foot boards on a 22" table is going to be interesting to say
the least.

I would either fasten a temporary table at least the length of your
board to the infeed table so the entire length is supported


or

I make glue joints with the table saw using an extension fence.

"ken blais" wrote in message
news:tFngf.11488$Mi5.706@dukeread07...
Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab
for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.


Could be technique, could be a drooping outfeed table. Check for that
first. Also check to see that what you have is really a concavity, and not
just a bit of tilt on the board in the center area. Make sure both sides
look concave.

If it looks pretty good, try jointing the ends off first, then going the
whole length. If you hold your board tight to the outfeed no more than
about eight inches from the cutters, even a droop in the table will diminish
in importance.

Oh yes, a longer table is more a convenience than a necessity, especially in
edge joining.

I use a 9' straight edge and a router flush cutting bit when having to give
a board over 7' a crisp edge. My jointer is not big enough to edge joint
much over 6'.

Jon
"George" George@least wrote in message
...

"ken blais" wrote in message
news:tFngf.11488$Mi5.706@dukeread07...
Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab
for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the
more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.


Could be technique, could be a drooping outfeed table. Check for that
first. Also check to see that what you have is really a concavity, and
not just a bit of tilt on the board in the center area. Make sure both
sides look concave.

If it looks pretty good, try jointing the ends off first, then going the
whole length. If you hold your board tight to the outfeed no more than
about eight inches from the cutters, even a droop in the table will
diminish in importance.

Oh yes, a longer table is more a convenience than a necessity, especially
in edge joining.

44-1/2" total length, ain't enuff tho...

--
Alex - "newbie_neander" woodworker
cravdraa_at-yahoo_dot-com
not my site: http://www.e-sword.net/

ken blais wrote:

Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab
for a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.

Any advice would be appreciated...
Thanks,
Ken

Ken,

I had a similar problem. For me, it was that I couldn't control well enough
the board when it was only supported by just the infeed (when starting) or
outfeed (when finishing) tables. Depending on how precise your work needs
to be, there are a number of ways you can do this. First, get one of those
8' metal straight edges and clamp it to the bottom of the board. Clamp it
in the middle (if possible) and at both ends. If that sort of straight
edge isn't good enough, then ignore everything else after this .

If you have a router, you can use a spiral bit to do a fair job, as has
already been mentioned. But if you have a radial arm saw whose front table
edege is square to the fence, put the saw into the rip position and run the
straight edge along the front edge of the table. Not only is this faster
than the router, but I've had better results over long cuts.
--
Michael White "To protect people from the effects of folly is to
fill the world with fools." -Herbert Spencer

On Mon, 21 Nov 2005 12:41:30 -0500, "ken blais"
wrote:

Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.

This may be asking an obvious question but are the boards straight to
start with? If not you may be accenting a problem that already exists
with a crooked board. Be sure you have straightened the board before
you put the final edge on it. Once your pieces are ripped from the
2x6, sight down the edge. If you see that they are already concave,
take a little off of each end until it's straight then make a final
pass.
While your jointer not have the longest bed, I'm confident that if
it's set up correctly you can get a straight 7' board with it.

Mike O.

Thanks everyone for your advice. I double checked my jointer and it turns
out the outfeed table was a little low, so i raised it to be level with the
blade at the highest rotation. that resulted in a better cut, but still
concave. So I started in the middle of each board and went towards the ends,
that got most of it. I clamped them up and the small cracks in the middle
disapeared...they look good so far.

btw, using biscuits for alignment in big glue-ups like this really
helped...i think i'll use them in every large slab i glue up.

"ken blais" wrote in message
news:tFngf.11488$Mi5.706@dukeread07...
Hi...I'm trying to edge joint some 7 foot boards so I can glue up a slab
for
a bartop i'm making for my garage. The boards are 1 1/4 thick and are
douglas fir (i used 2x6s from the local lumberyard). I'm having trouble
getting a straight edge, it seems the more i joint the same edge, the more
concave it gets. It's very slight but it seems the jointer is taking more
off the middle of the board than the ends. I'm using a Yorkcraft jointer,
6", 22" infeed table, 22 1/2" outfeed table. I haven't had this problem
with smaller boards, and i'm not sure if it's my technique, or a machine
setup thing.

Any advice would be appreciated...
Thanks,
Ken