Help with table top

[Joanne Coathupe]

Hi everyone

Could any help me with a problem I have been having please? I have been making dining tables using the Kreg jig, 2x8 boards and breadboard ends. I use a thickener planer to make sure all of the 2x8's are straight and equal depth but when I then screw them together to make the table top, the joint always goes out of alignment and leaves a 'lip' that I then have to sand down. Any suggestions please on what I am doing wrong and how I could improve the joint. 

Thanks in advance :)

[michael evans]

Hi joanne, i learnt early on when useing the kreg system you need too clamp everything together.Align your boards where you want them clamp in position then insert your kreg screws,they do tend too wonder if the workpiece not clamped in position.Another useful trick is too screw too battens 2"x1" at 90 degrees too butt your workpiece against before you clamp and screw hope this helps have a go ,mick.

[Ken Darga]

When clamping 2x stock, I've used 2x2x1/4" alum angle, positioned at 90 degrees to the joint, and located on the opposite surface where the screws are installed.

Clamping the angle firmly in place, so as to keep the surfaces in the same plane.

Position the clamps over the angle as close to the joined member as possible, so as to pull the surfaces flush.

 

I you only have 1 angle handy, locate the angle between two screws---i.e., install the screw on each side of the angle.  Move the angle to a new location, and repeat along its entire length.

 

When joining wide timbers, assemble two timbers along their entire length.

Then proceeded to add the 3^rd member, followed by the 4 members, etc.

 

This procedure will ensure the joined members are flush vs trying to clamp all the timbers together at the same time.

 

ALTERNATE: A straight 2x4 ---with the widest part clamped 90 degrees to the boards being assembled.  The wider portion will resist more bending than the thinner section.

[KregRep]

Are you clamping the joints when you screw them together? Because the Kreg screw goes in at an angle, it can pull the boards slightly out of alignment as the screw drives in. If you can place a clamp across the thickness of the boards at each end, that will usually keep the pieces from creeping as the screws drive in.

KregRep

[james wilhelm]

Hi Joanne , when I first set up my shop I built a 4 ' x 8 ' work bench , on the one end I made a glue up station !!  I screwed down 4 t tracks , then I cut two set,s of 3/4 " x 1 1/2 "  x  18 " and 30 "  , four of each  and drilled a hole in each end for the tee bolts , so I could lay the boards across the t tracks  , then I  take the four 1 1/2 " oak boards  , put them on the t bolts  and use them as a clamp to keep the boards flat , then I put a few bar clamps  across the boards to pull them together and keep  them tight !!  Also found this usefull  in using Kreg pocket hole screw,s  , keeps the boards flat and even  while you put in the screw,s !!!  Will try to take a picture of my set up and post it on the site , so it is more understandable , hope this is help full to your problem , Jim !!

[john gilbert]

Do you have a  photo of you work station? I am in the process of building my shop. John Gilbert
james wilhelm said:

Hi Joanne , when I first set up my shop I built a 4 ' x 8 ' work bench , on the one end I made a glue up station !!  I screwed down 4 t tracks , then I cut two set,s of 3/4 " x 1 1/2 "  x  18 " and 30 "  , four of each  and drilled a hole in each end for the tee bolts , so I could lay the boards across the t tracks  , then I  take the four 1 1/2 " oak boards  , put them on the t bolts  and use them as a clamp to keep the boards flat , then I put a few bar clamps  across the boards to pull them together and keep  them tight !!  Also found this usefull  in using Kreg pocket hole screw,s  , keeps the boards flat and even  while you put in the screw,s !!!  Will try to take a picture of my set up and post it on the site , so it is more understandable , hope this is help full to your problem , Jim !!

[james wilhelm]

Hi Joanne,  When I first set up my work station It was for gluing boards with biscuit,s !!Also found that It work,s well for holding the boards when using kreg screws !!!  You will need a table at least  4 ' x 4 ' , I screwed four 4 ' t tracks spaced out even on the table !!  I made the four clamp boards out of 3/4 " x 1 1/2 "  x 18 " and 30 " long, but youcan use what ever size boards you want, the oak boards worked well for me !! I bought the t track,s from Rockler, you can buy the 17 pcs. kit or just buy just the tracks, the kit # is 24063 and the 4 ft. tracks are 20054, thet are not cheap , but will last a long time !!  You will also need a few bar clamp,s , can get them from Harbor Freight, not to bad in price!!Also sending you some pics. and hope this helps you with your shop set up !! If you have any ?,s feel free to contact me! Have a great day , have fun building and be safe, Jim !!!

[michael evans]

Looks like a good set up too me jim.

[Russ Haynes]

1.  Lay the panel out, best face down, on a flat surface.  You want a panel to be flat with tight seams and any thickness gaps to be visible only on the non-face side.  Laying out the panel on a flat surface will cause all the face-side seams to align properly, making any imperfections show up on the back side of the panel.  The only (easy) way to accomplish this that I'm away of it is to put the best face down on an assembly table bigger than the panel you're making.

2.  Use straight-edged cauls and clamp the cauls down HARD to the flat surface when you do the glue-up.  The cauls will force the panel flat against the assembly table.  Jim's set up for cauls is as good as I've ever seen and I am hereby stealing it, pending arrival of more T-track from Lee Valley.  But you can get similar forces from taking another piece of lumber with a straight edge on it and clamping it on top of the panel, down to your table top.  That will force all of the pieces down to the table top, which we know is straight -- as long as all the pieces are fully pressured down to the table, the face of the panel will come out as flat as the table surface.

3.  Use an alternate method of panel joinery.  I love Kreg -- their clamps, their pocket-hole jigs, their mitre-gauge, routing accessories, rip cut, etc. (I've probably contributed more than my fair share to putting their kids through college) so nobody take this the wrong way:  Using pocket holes to join up flat panels is not as effective or easy as biscuits or dowels.  Even with a good jointed edges, the fact that the pocket screws go in at an angle will cause a panel to wander into a circular shape the more pieces you add on.  Also, unless the panel is big, heavy, or willget heavy-duty use, glue by itself is fine.  All of us probably have a tendency to "over-build" things.  But the fact is that modern wood glues are strong enough that panels made for normal use out of 3/4" material will be plenty strong with just glue.  Biscuits and dowels are really there to help align the boards making up the panel.

4.  Thickness planers are good, but just running the pieces through a planer is not going to give you pieces with a uniform thickness.  Take your calipers and run them down the length of the board -- they won't stay in the same position.  The only way to get pieces a truly uniform thickness is to make sure one face of the board is flat first -- that means you have to face-joint one side, then run the board through the thickness planer with the jointed face down.

[Jay Boutwell]

 Hi Joanne,  I read your post about your problems with glue up of panels.  I have years of glue up experience building cabinets and tables where large sections of panels are needed for things like doors and large butcher block counter tops.  I had good results with the below methods.  There is a sketch of a glue up rack that I made that was easy and inexpensive to build and worked well with large as well as small panel glue up.  This is from a topic discussion I posted on glue up racks and is found on my discussions March 4, 2011.  You will find it on about page 46 of my discussions.  I also posted it one time prior to this and it was in a discussion with a member "Doug".   Maybe this information will assist you with your work,

 

 ...........glue does two things for you in making panels.  #1. It makes them ridgid and stiff turning them into a one piece stock.  Alternate the wood growth rings and watch your grain figures so they make an nice looking top.  #2. By using the glue (I use tight bond)  you can get by using less number of pocket screws and have a stronger top in the end.   The reason I suggest watching and alternating the growth rings in the stock as it aids in preventing the "CUP" effect in the panel.  It is easier to use pocket screws and glue as you do not have the clamping problem however there are times when may not like to use screws.  Examples would be when you make glue up panels for doors and or any other panel where you can not hide the screws.

I normally do not use pocket screws on panels and glue all the joints and clamp them.  I have glued 4 foot plus wide panels and as long as near 8 feet at a time without any difficulty .  The biggest mistake often made is dry glue joints caused be either too less amount of glue or over tightening the clamp which squeezes out the glue making it a dry joint. 

On a small panel of about 3 to 4 feet long and maybe up 4 feet wide, the procedure I use is to cut my stock to rough length and then edge it by either saw and or jointer getting a straight line so all mating surfaces are tight.  I check all pieces for the "Cup problem" and if I need to use that piece, I will make a saw cut down the middle and the recut the edges.  I alternate the growth rings so that they alternate one up one down.   I lay out the grain pattern and make any changes I need to achieve what I'm looking for. Once I'm satisfied with the results, I draw a "witness mark" across each joint in at least two places and number the boards.  Taking the board which will become one of the edges, turn it up so the  glue surface is up.  On a flat surface that is big enough to support the stock when it is glued up and laying on it's surface I cover the surface with paper (News Paper works),  Use a large bar clamp and clamp the lower edge on each end.  Move the board to the edge next to you.  With the glue bottle begin at one end and making small figure "8* type circles cover the entire length of the joint.  Repeat the same on the a-joining board glue joint and stack on top of the first.  By pulling the one board one direction for a bout 2 inches and pulling it back you will have spread the glue.  Continue until you have glued and stacked each board and making sure to a-line all of  the witness marks.  The boards will want to slip at the joint so use a small hand squeeze clamp across each joint.  Once you are finished, holding firm pressure down on the top board remove the squeeze clamps and bar clamps and simply allow the glue up to fall onto it's back onto the paper covered table.  Check that all the  witness marks a-line and clamp the assembly.  Once clamped you can set the assembly back upright.  When glue begins to set use a sharp razor blade and remove the excess.  Using a 50/50 mixture of water and white vinegar to wipe away the glue will aid in removing large glue squeeze out . 

For large and difficult panel glue ups I use a homemade fixture made of 2x4's that I lean against a wall to hold the panels until I complete the glue work and  apply the clamps.   Enjoy and enjoy building the project.  

           

 

Jim here is a sketch of the racks I use figured I would just attach it

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Jim here is a sketch of the racks I use figured I would just attach it

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Jim here is a sketch of the racks I use figured I would just attach it