Feedback needed on gluing up table tops

[dirk martin]

I've got a potential customer asking me to make some table tops for him, out of 6/4 Sepele. He wants 48 x 30 rectangles....about 30 of them.

I've glued up 4/4 stock before with no issues.

Anything special I need to know, other than just make sure my edges are flat and straight? I've never used biscuits on edges before...is it neccessary?

What if I want to use some shorter boards, to get my 48" length, to minimize waste? I'll end glue in that case. Never done that before. Biscuits on the ends?

I'd probably do the Festool Domino thingy if you guys think I should.

[Steve Griffin]

I've used sapelli for quite a few countertops.

Gluing up 6/4 is the same as 4/4 only easier--it's easier to keep it flat with clamping pressure.

I only would biscuit if you absolutely need maximum thickness OR if you are not sending these through a belt sander. Otherwise, glue em up fast and as lined up as you can and take off 1/32+- on top and bottom with the sander and 80 G.

If you do use biscuits, put them in the middle and don't fill the pockets with glue, other than what gets in while applying glue to the edges. Speaking of glue, I'd use a 3" roller for sure.

I do end glue shorter pieces with biscuits with good results. But your waste factor may not be significant enough to bother. Besides, maybe those shorter lengths could be used for another project....

Also, I love cleaning up my edges for glueups with my shaper--instead of taking a glue rip blade pass on the T-SAW or a jointer pass. It's faster and you will have dead square edges to work with: http://www.sawmillcreek.org/showthread.php?t=135238

Might as well glue up to perfect width to, and save a trip to the T-SAW and have sawmarks to sand out...

Sounds like a good little project.

-STeve

[Neal Clayton]

does he want edges or faces pointed up?

the biscuits can help with alignment if you don't have another means of doing so.

alternatively might take the opportunity to justify the cost of a few panel clamps to do the same thing for less effort.

[dirk martin]

Faces up.
Any suggestions on a low cost panel clamp setup?

[Tom Hammond]

I make 48x30 (or so) tops all the time... albeit not this thick normally. One thing I started doing a few years ago and it changed my workshop life, so to speak, is this:

When I finish my layout of my boards to be glued up, I joint one face-to-the-fence, and the next face-away-from-the-fence, and so on. I found that a minutely. even indetectibly, out-of-perpendicular fence can lead to curved glue-ups. When I started using this technique, my glue-up troubles almost totally disappeared since my edges are parallel even if they are slightly out of square to the face... and I use simple Jorgensen clamps and cross-braces clamped across the ends, and that's it.

[Frank Drew]

Dirk

Using shorts is economical; the client might, or might not, like the look, so I'd check first. In any case, I'd use full length pieces on the outsides.

[dirk martin]

Tom, I'm not following you.
Jointing one face to the fence?.....

Are you saying you are jointing each edge twice, once with each face against the fence?

[Tom Hammond]

Tom, I'm not following you.
Jointing one face to the fence?.....

Are you saying you are jointing each edge twice, once with each face against the fence?

Dirk...

Let's say you have 5 boards laid out face up for glue up, numbered 1-2-3-4-5 in order. Make sure, when jointing the edges for gluing, you joint the odd-numbered boards with the face against the jointer fence and the even-numbered boards with the face away from the fence. Any variations of the fence not being perfectly vertical are compensated for in the next board's opposite variation, keeping the edges parallel even though they might not be exactly perpendicular to the face. In an extreme example, let's say all the boards' edges were mitered at 45 degrees. You could still do a glue up if mating boards had one miter facing up and the next miter facing down to keep the edges parallel.

[Prashun Patel]

A biscuit joiner will make alignment easier and will minimize the leveling work after. I'd put one in the center and one on each end.

If you have a bunch of cauls, then the biscuits aren't necessary.

I wouldn't use shorts. You're just making more work for yourself. I'm not sure what the sapele comes in, but you shouldn't have too much waste if it's available in 96" or 120".

[Chris Padilla]

Biscuits can work great for alignment and holding issues but just make sure they are correctly placed because they can quickly aid in MISalignment should you mess up a reference here or there.

BTW, I wouldn't bother gluing the biscuits at all...not necessary. That long-grain to long-grain joint will be very strong with modern glues.

Also, preselect your biscuits...some will be loose...some won't fit...some will be just perfect. You want the Goldilocks' biscuits. :D

[Frank Drew]

Tom's is a tried-and-true method for edge jointing that cancels out any slight variance from 90º between the jointer table and fence -- for example, one edge might joint out at 89º from its face and its mating board at 91º, but that equals a flat 180º when the boards are butted up and glued.

[Steve Griffin]

Why not just set the jointer fence to a perfect 90 degrees?

Though I can't say I've checked mine for months, since I run everything through the shaper with a power feeder for a perfect edge. My jointer is just for making a straight line or flat surface.

-Steve

[Jerome Hanby]

I make 48x30 (or so) tops all the time... albeit not this thick normally. One thing I started doing a few years ago and it changed my workshop life, so to speak, is this:

When I finish my layout of my boards to be glued up, I joint one face-to-the-fence, and the next face-away-from-the-fence, and so on. I found that a minutely. even indetectibly, out-of-perpendicular fence can lead to curved glue-ups. When I started using this technique, my glue-up troubles almost totally disappeared since my edges are parallel even if they are slightly out of square to the face... and I use simple Jorgensen clamps and cross-braces clamped across the ends, and that's it.

What a great idea! Very similar to clamping two boards together face to face and using a hand plane to take a few swipes across the edges to be glued together.

[Frank Drew]

Why not just set the jointer fence to a perfect 90 degrees?

In the logical world, yes, but in the real world fences can be ever so slightly off, they can move a bit when moving the fence across the table, the light in your shop might not be soo good, whatever. This method means never having to say you're sorry -- if the fence is precisely at 90º, you're good, and if it's slightly off, you're still good.

[Van Huskey]

In the logical world, yes, but in the real world fences can be ever so slightly off, they can move a bit when moving the fence across the table, the light in your shop might not be soo good, whatever. This method means never having to say you're sorry -- if the fence is precisely at 90º, you're good, and if it's slightly off, you're still good.

+1

"Perfect" is never perfect in the human world and even less so when you add a michine. When there is a simple no-cost (other than a few seconds of time to mark the boards) solution to the subtle inaccuracy of life it is worth it compared to the pain that can result from not doing it.

I would skip the biscuits if you have a widebelt or drum sander as long as the last 1/16" of thickness is not an issue.

[Michael Arruda]

Why don't you just run the pieces through a shaper to get an interlocking glue joint? No muss, no fuss, no misalignment- clamp it, glue it, you're good- as long as each piece has been planed/ sanded down to the same thickness pre glue up- I run each piece through a kissing pass on the planer without making any adjustments to ensure this- you don't have to worry about post rough prep for alignment- just final finish sanding.

-Michael