jointing problem - rocker on long edges
 

While trying to edge joint some 55" and 65" boards on my 6" x 46"
jointer I am regularly ending up with some rocker on the jointed edge.
The infeed/outfeed tables are parallel as near as I can measure, same
for the knives being equal in height to the outfeed table. I think I
am keeping the board registered on the outfeed table.

I am starting with the bow side down, take a few 1/64-1/32" or so
passes, the bow slowly goes away but by the time I get down to wood in
the high zone, I seem to joint in some rocker - I'd rather have it be a
spring joint. Once I have some rocker in the edge, I'd have to joint
off a tremendous amount of wood to get back to flat.

I figure I am making a classic mistake of some sort or have something
set up wrong that I am not thinking about. I'd sure appreciate some
tips or help.

thanks,

Steve

jointing problem - rocker on long edges
 

"Steve" wrote in message

I am starting with the bow side down, take a few 1/64-1/32" or so
passes, the bow slowly goes away but by the time I get down to wood in
the high zone, I seem to joint in some rocker -

What I do in that situation, and I don't know if it is standard procedure
but it works for me, is to joint (with almost no downward pressure) to the
middle where the bow is most prominent, then lift the board off the jointer
and flip it end to end and do the same until I finally get a pass over the
blades that takes a full cut.

Worth a try in any event ... good luck.

--
www.e-woodshop.net
Last update: 11/06/05

jointing problem - rocker on long edges
 

I used to have the same problem and after a few phone calls to discuss the
problem, I figured out that it was all on how I transitioned my hands from
the infeed to the outfeed tables. I wasn't maintaining pressure like I
should have been. Since correcting that, I haven't had a problem.

jointing problem - rocker on long edges
 

On 25 Nov 2005 19:10:03 -0800, "Steve" wrote:

I am starting with the bow side down, take a few 1/64-1/32" or so
passes, the bow slowly goes away but by the time I get down to wood in
the high zone, I seem to joint in some rocker - I'd rather have it be a
spring joint. Once I have some rocker in the edge, I'd have to joint
off a tremendous amount of wood to get back to flat.

I'm not sure if I understand the "bow side down".
If you were to lay the board (on edge) on a flat table and see a gap
in the middle, start your piece centered over the cutter and take a
little off of one end then turn the piece around and take a little off
the other end until you get the piece straight. If the bow is bad
enough you may need to make one pass closer to the end and the another
(on the same end) more towards the middle and repeat the same
procedure on the other end. Make the final pass with the grain
running in the correct direction after you've made the piece straight.
If the problem is the other way where your board (on edge) will rock
on a flat surface, start at one end and run to the middle of the
piece, then turn the piece and run back to where your first cut
stopped in the middle. Again, once the piece is straight, make your
final pass with the grain running in the proper direction.
If the piece is bowed (in either direction) you want to make the piece
straight before you make full passes.

Mike O.

jointing problem - rocker on long edges
 

"Steve" wrote in message
ups.com...
I figure I am making a classic mistake of some sort or have something
set up wrong that I am not thinking about. I'd sure appreciate some
tips or help.

Yes, it is a classic mistake, so you have _lots_ of company. As Swingman
says , the answer is to joint the high spots first.

You should always sight your board prior to jointing and attack the high
spots. Normally I take the hollow side first, because it's where the
sapwood is, and I don't care if I have a lot to remove. Then, as Mike says,
the procedure is to run the ends before the entire.

It helps to make a couple of physical X's opposite the high corners of a
twisted board when surfacing. Remind you that it's the left or right rear
corner you're removing. My mental X's sometimes move to the other side when
I reverse the board to take off the high corner.

jointing problem - rocker on long edges
 

I too have suffered with imperfect edges when jointing long boards.
I cannot determine if it is my technique to the jointer. Perhaps more of
the former than the later.
I gave up and if I need to joint a long board these days, I go one of two
ways
a) I clamp a straight edge to it and use my router. My straight edge is
two 50inch sections so I can straighten up to 8 ft. I do this outside except
in winter.
b) I hand plane to take off the bumps and use my router table. This takes
more setup than a) so I only do this in winter.

I have considered getting a jointer with a longer bed, since I think the
46inch bed is contributing to my technique problems.

Dave Paine.

"Steve" wrote in message
ups.com...
While trying to edge joint some 55" and 65" boards on my 6" x 46"
jointer I am regularly ending up with some rocker on the jointed edge.
The infeed/outfeed tables are parallel as near as I can measure, same
for the knives being equal in height to the outfeed table. I think I
am keeping the board registered on the outfeed table.

I am starting with the bow side down, take a few 1/64-1/32" or so
passes, the bow slowly goes away but by the time I get down to wood in
the high zone, I seem to joint in some rocker - I'd rather have it be a
spring joint. Once I have some rocker in the edge, I'd have to joint
off a tremendous amount of wood to get back to flat.

I figure I am making a classic mistake of some sort or have something
set up wrong that I am not thinking about. I'd sure appreciate some
tips or help.

thanks,

Steve

jointing problem - rocker on long edges
 

I'm not sure if I understand the "bow side down".


Concave side down. I have the same problem with the maple boards for my workbench,
ripped to 2-1/4" depth (top-to-bottom) from 8/4 stock there is bending to about 3/32" to
1/8" deep because I "ripped too soon" (foolish me). The end jointing from the center is
a good idea I had not though of (as Mr. newby) before.

What about simply wetting the boards, wet towel on top or wrapped and weighted with
cynder blocks, convex on top? That way, I should think I would not lose thickness of the
top (as completed) before handplaning to flatness. Would it work?

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

jointing problem - rocker on long edges
 

"AAvK" wrote in message
news:z6nif.10159$dv.5823@fed1read02...

What about simply wetting the boards, wet towel on top or wrapped and
weighted with
cynder blocks, convex on top? That way, I should think I would not lose
thickness of the
top (as completed) before handplaning to flatness. Would it work?


Nope. Once they dried, they'd return to the relaxed position.

jointing problem - rocker on long edges
 

Nope. Once they dried, they'd return to the relaxed position.


Okay... thank you... what if I do this anyway, and once flat remove
the towels yet put the cinder blocks back on, leaving the wood to dry
that way for a couple months? Would they spring back after that?

BTW this is some seriously hard, dense, heavy and very glassy smooth
maple.

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

jointing problem - rocker on long edges
 

"AAvK" wrote in message
news:Sroif.10163$dv.3071@fed1read02...

Nope. Once they dried, they'd return to the relaxed position.


Okay... thank you... what if I do this anyway, and once flat remove
the towels yet put the cinder blocks back on, leaving the wood to dry
that way for a couple months? Would they spring back after that?

BTW this is some seriously hard, dense, heavy and very glassy smooth
maple.


I've dried a few thousand feet of hard maple, and there's no way I know to
bully it and get off scott free. I tried wedges on a stack inside frames
like they did in an ancient FWW, beginning with green lumber rather than
dry, and some still chose its own way when the wedges were released. After
that, I just sticker, stack, and wait, not weight.

jointing problem - rocker on long edges
 

I've dried a few thousand feet of hard maple, and there's no way I know to
bully it and get off scott free. I tried wedges on a stack inside frames like they did in an ancient FWW, beginning with green
lumber rather than dry, and some still chose its own way when the wedges were released. After that, I just sticker, stack, and
wait, not weight.

Okay... and again, THANK YOU!... I think I will take mike O.'s technique. I have
access to a monster 12" Oliver jointer which has a something like a 90 some-odd
inch long table, and these boards of mine are around 60", that way would work
perfect on it even if one direction would be going against the grain to do it (a very
"iffy risk I think). After that, the Oliver planer for the convex side but I think I might
get to 1-7/8" final thickness.

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

jointing problem - rocker on long edges
 

I'm not sure if I understand the "bow side down".
If you were to lay the board (on edge) on a flat table and see a gap
in the middle, start your piece centered over the cutter and take a
little off of one end then turn the piece around and take a little off
the other end until you get the piece straight. If the bow is bad
enough you may need to make one pass closer to the end and the another
(on the same end) more towards the middle and repeat the same
procedure on the other end. Make the final pass with the grain
running in the correct direction after you've made the piece straight.
If the problem is the other way where your board (on edge) will rock
on a flat surface, start at one end and run to the middle of the
piece, then turn the piece and run back to where your first cut
stopped in the middle. Again, once the piece is straight, make your
final pass with the grain running in the proper direction.
If the piece is bowed (in either direction) you want to make the piece
straight before you make full passes.

Mike O.


Thanks for the technique Mike, I will use it but I don't know about that
chopping against the grain, one never knows how much will get chopped
off.

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

jointing problem - rocker on long edges
 

Steve wrote:
While trying to edge joint some 55" and 65" boards on my 6" x 46"
jointer I am regularly ending up with some rocker on the jointed edge.
The infeed/outfeed tables are parallel as near as I can measure, same
for the knives being equal in height to the outfeed table. I think I
am keeping the board registered on the outfeed table.

I am starting with the bow side down, take a few 1/64-1/32" or so
passes, the bow slowly goes away but by the time I get down to wood in
the high zone, I seem to joint in some rocker - I'd rather have it be a
spring joint. Once I have some rocker in the edge, I'd have to joint
off a tremendous amount of wood to get back to flat.

I figure I am making a classic mistake of some sort or have something
set up wrong that I am not thinking about. I'd sure appreciate some
tips or help.

thanks,

Steve


If I am understanding you right, I was seeing something very similar with my
jointer a while back. It turned out that my outfeed table had a sag in it
that no amount of technique could compensate for.

-John in NH