Jonathan McCully

TableTop Alignment

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Starting to contemplate how I might ensure alignment of my tabletop during glue-up. Have seen multiple suggestions for use of biscuits and had one suggestion from a friend to use beadlocks. It seems that some woodworkers won't use anything other than their glueline and clamps, but I'm not sure that I'm quite so optimistic about my ability to maintain alignment.  Unfortunately, I don't have a biscuit jointer or beadlock system and am curious if you all have any other suggestions before buying a new tool.  Thanks.

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Cauls come to mind, you can make them yourself. How big is the top you’re glueing up? You may need 3 or 4 pair for the job and depending on the width you may want to cut them with a slight arch to put more pressure in the middle  

 

 

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24 minutes ago, Jonathan McCully said:

Starting to contemplate how I might ensure alignment of my tabletop during glue-up. Have seen multiple suggestions for use of biscuits and had one suggestion from a friend to use beadlocks. It seems that some woodworkers won't use anything other than their glueline and clamps, but I'm not sure that I'm quite so optimistic about my ability to maintain alignment.  Unfortunately, I don't have a biscuit jointer or beadlock system and am curious if you all have any other suggestions before buying a new tool.  Thanks.

Plenty strong with just the glue.  Slayer is correct in that cauls can do a great job of keeping things flat as well.

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That's a big top. A well jointed edge goes a long way in helping out as well. I'd probably do cauls and  a couple dowels. dowels are tricky though.

 

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Me and dowels just don’t get along and that speaks of my ability. Once they are in the clamps, there’s no adjusting them.  Same way with biscuits but at least there is lateral adjustments. + 3 or 4 on the cauls. Want to impress your lady friend, buy a Domino and, it’s multi-functional. If she’s your wife, find a way around to letting her know you bought it. Mine’s not as easily impressed as she once was. 

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4 minutes ago, wdwerker said:

Unless you have a large long bed jointer a tracksaw might be your best way to achieve clean tight joints. Cauls will help align the individual boards, I wrap mine with clear packing tape so the glue doesn't stick to them. You might glue up just 2 boards at a time then assemble those pairs to sneak up on a wide top. 

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I like the biscuits for alignment.  The tool price is modest and you will have it for years. And you will protect your investment in the wood. What kind of wood will it be?

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Not to just toss in a link, but this recent video from Izzy Swan demonstrates a combined caul & clamp device he built. I appears incredibly effective for panel glue-ups.

None the less, straight and square edges are critical for achieving a good joint. If you don't have a large jointer or a quality track saw, hand planes will do the job, but do require patience.

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Assuming you have a Thicknesser, how wide is it?

I found it easier for my tabletop to glue it up in 3 sections, run the sections through the Thicknesser and glue those up. It was fairly straight forward. I did use dominos to help line everything up. Biscuit joiners are cheap though. 

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4 minutes ago, lewisc said:

Assuming you have a Thicknesser, how wide is it?

I have a dewalt 735, so I have 13 inches of width. Most of the stock I have is currently around 7.5 inches wide, so not sure I'll be able to get even 2 boards through the planer. Will likely get them as smooth as possible prior to glue-up, trying to align them as stable as I can (hence the thread) and then just finish the top with hand planes/sander.

 

3 hours ago, curlyoak said:

What kind of wood will it be?

Black walnut

 

I appreciate the suggestion on a track saw for the long edge jointing.  My jointer is only 56in long, so probably will need to use something else to put a nice edge on the boards before glue-up.

 

10 hours ago, K Cooper said:

Me and dowels just don’t get along and that speaks of my ability. Once they are in the clamps, there’s no adjusting them.  Same way with biscuits but at least there is lateral adjustments. + 3 or 4 on the cauls. Want to impress your lady friend, buy a Domino and, it’s multi-functional. If she’s your wife, find a way around to letting her know you bought it. Mine’s not as easily impressed as she once was. 

It is my wife and she is definitely not as impressed with my tool purchases as she once was.  She is more impressed with my completed projects (most of which are for her), but I'm such a perfectionist that it takes me quite awhile to get them done which I think bothers her a bit. I also can tell that she doesn't like me spending time working on shop projects (even though she knows they are necessary for producing nice furniture).

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I love working with walnut. What grade is it? Look at the end grain. You don't want the center of the tree. Before you run it through your thickness planer it is important to flatten one face. That is done easily on a big jointer. But it can be done by hand using a straight edge and a hand plane. However 8' would demand some very straight and true lumber to start. On occasion when my equipment is not enough I have paid for millwork from a local shop. I needed 12" wide lumber face dressed. It was quick, easy, and a small cost in the big picture. You might ask for it dressed on 4 sides also. Ready to glue...A few options...

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I'm a big DowelMax fan. As far as doweling jigs go it's expensive, but it's cheap in comparison to a Domino. And- most importantly, it's *not* a dowel centering jig. When I'm doing a tabletop glue up, I don't want the centers of the boards to line up... I want the tops of the boards to line up. If the boards are EXACTLY the same thickness, aligning their centers works... but if they're not- it doesn't matter, you just hide the slight differences on the bottom, and all of the boards are still perfectly flush with each other on the top. It eliminates the need for cauls, and takes a lot of the stress out of the glue up process. Plus- it's so precise that, once you remove the squeeze out- your top should be perfectly flat, you don't have to sand or plane away any small differences from board to board. I pretty much jump right to finish sanding- no extra flattening required. The DowelMax has a ton of other uses besides aligning boards for a panel glue-up... you can do pretty much any Domino-style joint with a DowelMax... but this is a really handy one.

Attached a pic of a panel glue-up from my most recent project; this pic was taken after taking it out of the clamps and just scraping off the glue squeeze-out. That's a 38" straight edge run diagonally across most of the panel... there's no daylight anywhere under that thing.

IMG_9401.jpg

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That is a sizable top for glue-up. Some method for maintaining alignment would certainly be desirable. Lots of good advice above. My 2 cents worth...

Clamping cauls could certainly work. I use them frequently. However, keep in mind that, in order to work the best, they need to have a bit of a curve to them so that you can get good pressure in the center of the glue-up. I would judge that you should have a pair at  16-18" intervals.

Of course, your mating edges need to be well jointed whether done on a jointer or table saw.

Biscuits are easier to use than dowels. However, in my experience, their fit is a little too sloppy to assure perfect alignment of the glue-up surfaces. Dowels would work better, but have the disadvantage that they need to be perfectly aligned or assembly becomes very difficult. Extra care required. If you do use them, keep in mind that large ones are not required for alignment purposes. 1/4" would probably be adequate.

One option that hasn't been mentioned is a continuous spline. If you have a router, all you need is a small investment in a  slot cutting bit. Then you can cut your spline to fit snugly. If you don't want the spline to show, be sure to stop the slot and spline well short of where your final end cuts will be. Actually, your spline doesn't need to be continuous. Make several short ones if you like.

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18 hours ago, Minnesota Steve said:

I think this type of doweling jig would work well...  I bought one last year and want to try it for panel glue ups as it indexes off the top of the board, not the center like some jigs.

https://www.rockler.com/doweling-jig-kits

 

That's what I had in mind when I made my post, i was just too lazy to find the link.

Truth be told I haven't used dowels for a panel alignment...I use my Domino, or more frequently just use cauls to get it close enough to clean up later.  The idea is solid though, except there will be no room for error unless you shave down a side of the dowel, and that will probably lead to a loss in some of the alignment benefits.

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With my excellent jointer I never use cauls. After the edges are buttered, I start clamping in the center. As I move to the next clamp working from center out I pull and push at the end of the board to have it align. Sometimes I have to go beyond alignment and then back to allow the area near the center to align. The tite bond 3 gives me plenty of time to play with it. If there are too many boards then I do a few at a time then glue it together. Sometimes with the bar clamp near the end The very end needs added alignment. There I use a c clamp. Also if it is flat sawn material I make sure to alternate the end grain up and down...That adds to flatness...I do alternate the clamps. top, bottom, top etc

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2 hours ago, bleedinblue said:

That's what I had in mind when I made my post, i was just too lazy to find the link.

Truth be told I haven't used dowels for a panel alignment...I use my Domino, or more frequently just use cauls to get it close enough to clean up later.  The idea is solid though, except there will be no room for error unless you shave down a side of the dowel, and that will probably lead to a loss in some of the alignment benefits.

Well I don't have a Domino or a bisquit joiner... so I thought I'd give it a try.   I bought it to attach some trim pieces to the edge of plywood and it worked fairly well for that.

Some day I want a Domino... but I'm waiting for Festool to raise the price even more. :-)

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