# lamination/glue-up question



## NewAtWood (Mar 17, 2011)

Hi,

I'm laminating about 20 7' 2x4's (doug fir) into a 30" wide top. I put an outdoor thermometer in the garage and its reading about 60 degrees F with 50% humidity. Planning to use titebond II since I have a bunch of it. I was going to clamp 4-8 boards at a time (trial and error on how many I can keep aligned at once, since I've never done this before) so I can run them through a planer.

My questions, 

1. Do you recommend applying glue to both sides of the middle boards, or do you just put glue on one side before putting them together?

2. How long do you recommend I leave them clamped for the glue to dry before moving on to the next set of boards? With the small things I've done, I've usually let them dry overnight before taking off the clamps. If I'm doing 4 or 5 long boards at a time, I'm hoping I can do more than one set a day. Any suggestions?

Thanks in advance.

Thanks!


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## HowardAcheson (Nov 25, 2011)

First suggestion. Go through at least two dry fits to be sure you have enough clamps and that they are pre-positioned where you can get to them efficiently.

Second, have some plan on how you are going to keep the boards from sliding in the adhesive as you apply pressure to the clamps. Clamp on some cross pieces is one solution.

Third, you need a way to get the adhesive on quickly and effectively. I use 4" "trim" paint roller. It comes in a kit consisting of the roller, roller holder and the kit cover is used as the paint (in this case, glue) holder. I put adhesive on both mating surfaces. Allow the adhesive to dry for 6-8 hours before removing the clamps.

Fourth, you don't say that you plan to rip the 2x4's to remove the curved corners. This needs to be done before you glue them up. It's way too much to attempt to remove after the boards are glued.

Fifth, to have the planed surfaces turn out the smoothest, orient the boards with the grains running in the same direction.

Sixth, air temperature is no where near as important as the temperature of the wood. The temperature of the wood should be maintained at no less than 60 degrees for at least 24 hours. If it gest any lower, your adhesive will take longer to dry. Below 55 degrees, it may not dry at all. 

Finally, you are going to need a clamp every 6-8 inches for the best adhesion.


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## bigcouger (Jan 4, 2012)

HowardAcheson said:


> First suggestion. Go through at least two dry fits to be sure you have enough clamps and that they are pre-positioned where you can get to them efficiently.
> 
> Second, have some plan on how you are going to keep the boards from sliding in the adhesive as you apply pressure to the clamps. Clamp on some cross pieces is one solution.
> 
> ...


 
+1 on that get the rolled edge off first an put down newspaper so excess glue want adhear to where you are glueing up on


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## Cliff (Feb 5, 2012)

I'm assuming you are laminating them up so the 4" faces are glued to each other

Biscuits dowels or a spline all will help you not have to futz with the boards as you lay them up together and prevent slipping around under clamping. 


You don't have to glue it all up at once - - you know this yes??? 
You can glue up some on day and more the next and in a few days have it all done. This is helpful expecially because clamping energy will be diffuse when you are clamping many boards as opposed to a few and clamping energy is important to a good glue joint. So, the fewer boards you are forcing together, the better. 



If you lack sufficient clamps to span the length of the glue up you might try this:

Buy three lengths of 1/2-13 All-thread (& 6 nuts & 12 big washers) long enough to go through your glue up.
Buy two large 6"x6" framing members the length of your glue up.

Locate and drill holes 6" from the ends and middle of all the boards to let the all-thread pass through.

Use biscuits of dowels or whatever to ensure location and no slipping during glue up and put it all together run the allthread through with the 6x6 beams in the sides and squeeze it all together with the all-thread and nuts. Of course - Using what clamps you have also. You can remove the all-thread when done and plug the holes.


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## Steve Neul (Sep 2, 2011)

I would rip the round edges off first and glue all 20 boards at one time. If you make four or five seperate glues, you might have to straighten them out on a jointer before you laminate them. It's a big undertaking to glue 20 boards together so if you can recrute some help to spread glue it would help. You don't need 100% coverage, just run some beads about an inch apart down one side of each board. Unless you plan to use the panel on an exterior application I believe you would have more open time with Titebond yellow glue. I also will shoot a 16 gauge nail in the boards to hold them in place while I clamp them down. When you clamp them down they will try to move on you otherwise. You would need a pipe or bar clamp at least one every foot down the top. I would leave them clamped overnight.


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## NewAtWood (Mar 17, 2011)

Thanks all for the suggestions/responses. Very helpful. I should have given a bit more info. I did rip off the round edges, I have 8 pipe clamps and 4 bar clamps to suck the 7' boards together, + some F clamps/and a few other hand clamps to keep the height right. I am gluing them on the 3 1/2 face, not the 1 1/2" edge. I was only planning to glue 4 boards at a time (or as many as 7 or 8 if I can manage it at one time and still get good clamping pressure, glue doesn't set up too fast, etc). Then I'd have 4 or five sections of about 4 or 5 or 6 or maybe 8 boards each that I can run through the planer...then glue the sections together after planing.

I just wasn't sure how long I need to keep each section clamped for the glue to dry before un-clamping and moving to clamping the next section. 30 minutes? 4 hours, 12 hours, 24 hours, etc (given my temps/humidity)? If I'm safe to take off the clamps after a few hours, for example, then I can probably get in 3 or 4 sections a day until I'm done. If I need to leave each section clamped for longer, overnight or 24 hours for example, it'll take longer than I want to wait. In my few small projects thus far, I usually leave clamps on overnight and haven't had a problem. But I'm hoping that clamping overnight was excessive and I don't need to wait that long, but haven't done a top before...or much gluing in general. Also, this is assuming the boards are reasonably straight and dry fit together pretty well. Thanks again for all of your help and input.


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## dseevers (Mar 24, 2011)

Personally the least amount of time I would do is 8 hours. 12 plus would be best.


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## cabinetman (Jul 5, 2007)

I would cut off the eased edges. In addition, I would face joint one side and plane the other, then joint. I would also edge joint both edges. 

Reason being if the two faces aren't parallel to each other, when they are glued up, their stacking could go askew. IOW, they won't glue up and stay lined up.

If the edges aren't 90 degrees to the face, and parallel to each other, it may be difficult to line up the edges for gluing. One edge could be higher than the other, or being "stepped". 

I would use alternating (top and bottom) mounted clamps, and use cauls to keep the alignment. No dowels, biscuits, or through rods.










 







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