Movement during glue-ups

[Nathan Duricek]

Hey guys, So i've done 6-8 large scale, dining/ conference tables for clients and when I'm doing just a single joint with two larger slabs I get great results. However, lately i've had clients requesting lumber that's tougher/ more expensive in large slab form. So, I've been doing large glue-ups. This current job I'm about to start i'm building three 10' x 4' 6/4 walnut tables. So I'll have 6-8 boards that i'll be biscuit-ing & jointing together for the width. On previous tables like this I've had a little movement from one board to the next of 1/16"-1/8". I've been using the 3/4" Bessy pipe clamps to joint, along with a small, flat piece of aluminum I-beam to clamp across the top to keep the surface flat.

My question is, are the clamps causing my issue since they bend a bit when tightened (not overtightening)? would parallel clamps from dubuque, bessey, jet, etc fix this? is it just going to happen across a 4' span of 6-8 boards gluing up? or is my old porter cable biscuit jointer just giving too much play (doesn't feel like it, they're a nice, tight fit sliding in)

Thanks guys, just trying to figure out what I need to do to save myself hours of surfacing these tables after the glue-ups.
Nate

[Andrew Hughes]

Hi Nathan, do you prepare your boards with a jointer and planer ?
If not that should help a lot.
Good Luck

[Nathan Duricek]

I don’t personally, but I have my lumber supplier/mill do it. I check the boards and they’re good, so I don’t think they’re sliding from not being in square.

[Mel Fulks]

Something like that has to be done by someone with skill. And usually with boards that long you have to adjust the
jointer outfeed table a bit. Delicate stuff. If the pieces were not carefully faced before planing that is a problem too. I like to mark the board faces and order before edge jointing ,then joint one face in ,next board face out to asure non bowed
flat top.

[Andrew Hughes]

Mel took the words right out of my mouth.
If your going to pursue woodworking a jointer and planer are handy machines to have. Sometimes the guys at the lumber yards make mistakes.
Good Luck

[Doug Dawson]

Mel took the words right out of my mouth.
If your going to pursue woodworking a jointer and planer are handy machines to have. Sometimes the guys at the lumber yards make mistakes.
Good Luck

Yes. Long jointer (and of course the planer), done right before glue-up. Parallel clamps rather than pipes, and in spite of the biscuits you should still be using cauls (cheap to DIY). A ten-foot-long glue-up can be a bit intense without them. The role of the biscuits is to prevent the boards from flying all over the place in the rush to get it done. :^) And nothing beats a practice setup.

BTW, the Lamello glue applicator really speeds up the biscuit install, which otherwise would take longer than striping glue on the boards. Without gluing the biscuits, they don't align as well.

[Jacob Reverb]

That's something I fight with, too. It seems the glue acts as a frictionless surface like an oil film between the boards, and the slightest bending of the clamps makes the boards slide all over as the glue squeezes out. I've never used biscuits for alignment (never did a glueup that big, either), but I do alternate the clamps (one pipe clamp above the glueup, the next clamp below the glueup) and use cauls, both of which help some. Still, it's always a mad dash, with (usually) some new cuss words invented.

[Nathan Duricek]

BTW, the Lamello glue applicator really speeds up the biscuit install, which otherwise would take longer than striping glue on the boards. Without gluing the biscuits, they don't align as well.


I've got an old craftsman jointer at my parent's house that I've thought of bringing over & tuning up. We may get to that when I get this batch of lumber & check it.

Also, I'm looking online @ Lamello glue applicators. Do they have anything that's not pressurized? even their 1 gallon applicator is around $800. feels a bit much just to apply glue. Sweet looking system though, no question

[Doug Dawson]

I've got an old craftsman jointer at my parent's house that I've thought of bringing over & tuning up. We may get to that when I get this batch of lumber & check it.

Also, I'm looking online @ Lamello glue applicators. Do they have anything that's not pressurized? even their 1 gallon applicator is around $800. feels a bit much just to apply glue. Sweet looking system though, no question

The one I was referring to is the Lamello Dosicol 20, I just checked and it's US$89 from the Home Depot. One squirt and done, very efficient. Yeesh, the price has gone up a bit. Still, way cheaper than the pressurized system.

[Brian Holcombe]

You need a pretty long jointer for 10’ boards, I put extensions on mine for work that long.

Also, you can glue two boards at a time, significantly reduces the chance of an error and gives you a chance to tune your edges and maintain overall flatness.

[Rick Potter]

Nobody uses dowells?

[Doug Dawson]

Nobody uses dowells?

Biscuits are much more forgiving, particularly on a big job like this.

[Kevin Jenness]

If you use enough biscuits with a decent machine held flat to the reference surface you should be able to get the boards within 1/64" of one another. I often use biscuits with a 30 year old Virutex, leave the blanks 1/32" over thickness, then run them through a wide belt taking off .010" at 100 # from each side to level the joints and remove tearout and .005" at 150# to make ready for finish sanding with a stroke sander and ro sander. There is no good reason to have to take off 1/16" or more to flatten a glueup.

I mill my own material and unless the material is contrary I space biscuits about 12" apart. When I do wide tops like the ones you are talking about I glue them up and sand them in halves then glue the halves together- the halves are easier to handle and fit through the widebelt I have access to. I take more care to get the final glue joint level, using a horizontal mortiser with dowels or a Domino machine for registration. I could do that throughout but using biscuits is a habit and gets close enough for the sanding process I use. Of course this tactic requires a way to joint the two halves, like a substantial jointer, long stroke slider or straightline rip saw. You could use a router and straightedge or track saw but with more effort. A small Craftsman jointer is not up to the task.

I don't use cauls, just alternate clamps top and bottom and rest the boards on straight p-lam clad 2"x2 1/2" sticks. If the boards are flat and the joints square the glueups come out flat. I use aluminum bar clamps, but pipe clamps work as well.

If you are making a business of building tables you should plan on investing in equipment that will help you be efficient.

[Brian Holcombe]

It may be worth explaining to potential clients that wide high quality material is your preference because it saves time which typically comes at a higher expense than material. It also looks better.

[Chris Montoya]

To combat movement during a glue up next time just sprinkle a bit of salt on the glue before joining. This allows for a bit of bite between the two pieces and almost eliminates any movement completely.

[Doug Dawson]

You need a pretty long jointer for 10’ boards, I put extensions on mine for work that long..

I was working with some 10 foot oak boards last week, for a large shelving unit, and my 7 foot jointer bed (PM882) would have done the job, but I thought it would be a bit awkward to move them across it (5/4, fairly heavy, and I'm an old man.) So I used a Stanley #8, tuning the edge against an 8 foot straightedge. With a sharp blade, it worked pretty well. I don't usually work with longer than 8 foot boards for components. Just a thought for the OP re how it could be done without a stationary jointer.

[glenn bradley]

Nobody uses dowells?


Biscuits are much more forgiving, particularly on a big job like this.

The "forgiveness" is his primary problem. If he wants a method to keep the boards aligned I would take dowels I made myself over biscuits and a spline over either.

410975

Nathan, good face jointing will assure success with this method. S2S or skip-planing from the yard doesn't count BTW. Route yourself a nice 'known-width' groove, mill your spline stock to fit snug and you're all set.

410976

If the ends will show (no breadboards) you can run stopped groove and make the spline a bit short of each end.

[Doug Dawson]

The "forgiveness" is his primary problem. If he wants a method to keep the boards aligned I would take dowels I made myself over biscuits and a spline over either.


That's what the cauls are for.

[Prashun Patel]

doing then one at a time allows better control.

If the edges are live, make blocks to fit over the end so the clamps don’t damage the edge and pull the pieces together at right angles . Trying to pull together a slanted live edge makes it harder to control slipping.

If you are going to be doing a lot of these, it is worth it to get good at hand jointing. It is good for correcting errors from an 8-12” jointer. A hand plane will also make quick work of flattening the seam. This can be done across the grain so the rock of tearoit is eliminated.

[Jerry Wright]

Also, too much glue - increases slipping and sliding.

[al heitz]

Chris beat me to the salt trick.

[Andrew Hughes]

If you take the salt, biscuits and bread board ends and put them all together it remind me of supper time.
Just saying :)

[glenn bradley]

That's what the cauls are for.

Quite true and my preferred method. It sounded to me like the OP was after something else :-)

[Patrick Kane]

If you plan on doing a lot of these, the festool domino will become your best friend. Like everyone else said, milling your own boards is first priority. I dont mill lumber for a panel unless its going into clamps that day. From what i read, you are getting S4S boards that might be freshly surfaced, or surfaced months ago and then stored. Not that i know a ton about lumberyard functions, but i doubt they fire up their moulder to do a 6-8 board run.

[Mel Fulks]

If you take the salt, biscuits and bread board ends and put them all together it remind me of supper time.
Just saying :)
That is the unvarnished truth!!

[Mike Henderson]

To combat movement during a glue up next time just sprinkle a bit of salt on the glue before joining. This allows for a bit of bite between the two pieces and almost eliminates any movement completely.

While salt will work, I'd recommend fine sand instead. What you want is something to combat the sliding. Most glue is water based and the sale can dissolve in the glue and you lose that "roughness". Also, salt is corrosive and sand is not.

Mike

[Bill McNiel]

Given the lack of an appropriate jointer or solid hand plane skills, I would suggest simultaneous jointing using a track saw (either purchased or shop made). Clamp the two boards, edge to edge, to a flat surface and rip the entire length of joining. With this process it doesn't matter if the blade is dead perpendicular or the cut dead straight as you will have a mirrored joint line in both axis.

Glue up in two board segments as suggested by others. I believe that using cauls for glue-up produces a coplanar surface more reliably than biscuits.

As always - just my opinion based on personal experience.

[Doug Dawson]

Given the lack of an appropriate jointer or solid hand plane skills, I would suggest simultaneous jointing using a track saw (either purchased or shop made). Clamp the two boards, edge to edge, to a flat surface and rip the entire length of joining. With this process it doesn't matter if the blade is dead perpendicular or the cut dead straight as you will have a mirrored joint line in both axis.


The longest guide track I know of, the Makita 118", is not long enough to do 10 foot boards (even if it didn't need the overhang.) But for shorter boards it would work. As you say, the edges need to be done simultaneously (the Makita 118 e.g. is not usually reference straight.)

[Mel Fulks]

While salt will work, I'd recommend fine sand instead. What you want is something to combat the sliding. Most glue is water based and the sale can dissolve in the glue and you lose that "roughness". Also, salt is corrosive and sand is not.

MikeI like the sand idea,and suggest a warning label about what happens to the planer if the people of the
future have thoughts about turning it into bird houses and cutting boards.

[Andrew Hughes]

If you add sand then you will have biscuits and grit. Breakfast dinner :)

[Dennis Peacock]

I've done and are still doing tops like this one. This pictured island top is 5 feet wide by 10 feet long and is 1-7/8" thick. No biscuits, no dowels, no salt or sand. Just good cauls, a well thought out process for glue up, and high quality clamps...lots of them....and I use no pipe clamps unless it become necessary for me to make a 12 ft long clamp for larger projects.

411031

[Jacob Reverb]

Sand in the glue has got to be RUFF on plane irons...

[Bill McNiel]

The longest guide track I know of, the Makita 118", is not long enough to do 10 foot boards (even if it didn't need the overhang.) But for shorter boards it would work. As you say, the edges need to be done simultaneously (the Makita 118 e.g. is not usually reference straight.)

Put two tracks together.