Panel glue up

[Brian Runau]

I am really terrible at this or is it the wood. Bought some walnut S2S. One side was truly flat and it was 13/16 thick. One board was bowed 1/8 inch along the length.

Should have used it for kindling,but walnut is expensive...

So I have a 4 panel 16" glue up @ 60" long with 4 1x4 in walnut. I have a couple cauls I built to keep the boards even during glue up, but since the boards are not true flat how can I pull these down at the joints for glue up so I am not sanding off 1/16 in spots across the face of the panel?

I find wood working a very humbling hobby.

Thanks for any help.

Brian

[J.R. Rutter]

Start in the center and tighten one clamp with everything aligned. Work your way out to the ends, tightening each clamp while using something like a smaller one hand clamp to lever the bowed board so that the joints are flat where you are clamping across the panel.

[Mel Fulks]

I have no doubt that J.R's method is working ,but I prefer using spring clamps to keep ends flat ,then putting a bar clamp lightly on each end. Since I always use "spring joints" I can then press down slightly in center to align before tightening a clamp in the middle. But many of the panels have been used for exterior work and I consider that method more important there ,just easier for me to do all of them same way.

[Brad Barnhart]

both ways will work, but were it me, I'd start in the middle with a bar clamp. Reason being is you can gradually increase clamping pressure from the center out. Using bar clamps, clamp one side of center then the other, all the out to the ends. You may have to use stickers to keep your glue up level the full width of it.

After you've got your glue up together & clamped, go back to the center & start tightening your clamps again. Being careful not to over tighten. When you see glue squeeze out, your clamps are tight enough. If you over tighten, you'll warp your glue up. Leave it set over night, if possible. When you take your clamps off, use a chisel & clean the dried glue off, then you can check for level, & use a hand plane to take down the high spots. Then do your sandin' & what have ya from there.

[Jerry Miner]

"A couple cauls" is not enough. For a 60" panel, I would use 4 pairs, evenly spaced.

[Phil Mueller]

If you feel like glueing 4 boards at once is a bit overwhelming, glue it up in stages. Just glue two - once those are dry, join the third, let it dry, then the fourth. Keeps the stress level to just worrying about one seam at a time.

[Brian Runau]

http://www.homedepot.com/p/Everbilt-1-in-x-48-in-Aluminum-Square-Tube-with-1-16-in-Thick-801307/204273940

What if i used five of these spaced across top and bottom clamped tight from the inside out with clear shipping tape between the metal and wood?

Thanks.

Brian

[Jerry Miner]

A curved caul would work better. Even a bowed 2 x 4

I don't think that aluminum tubing would provide much pressure in the center of the panel. Save your money and get or make some curved cauls.

[Robert Engel]

Brian,

Panel glue ups are a big deal for every ww'er. Don't get frustrated we've all been there. You watch the guys on YouTube do it and wonder what's wrong with you, right? Well yes, sometimes it IS the wood but with experience you will be able to eliminate problems. Learning to select and prepare the wood is where it all starts. I wouldn't worry about 1/8" bow in 60 that can be taken care of during glue up. I worry much more about grain direction and the potential for a board to cup. When that is all set, make a big triangle on the face pointing toward the front.

Before I make a suggestion, let me say we've all been humbled and frustrated at some point with panel glue ups. Let me also say IMO dealing with surfaced lumber is THE biggest source because there is no extra material to work with and this really puts the pressure on for perfectly aligned joints.

The best way to ease the pain is start with thicker material than the final. I also do not fret about alternating growth rings, etc. I only look at the face grain to obtain the most pleasing arrangement. A pay the most attention to the edge joints, making sure they are perfect. I am a big fan of spring joints.

By flat, I'm referring to flatness across the face of the board (or cupping), not bowing. Cupping is more important because you can't reference a 90° edge off a cupped board. Often times a bow can be cancelled out by pairing it with another boards bowed the opposite way.

There are two basic ways to address alignment: 1) mechanical aids such as biscuits, splines, Dominoes, etc or 2) clamping aids or 3) nothing.

Personally I use a rubber mallet to tap the high spots as I incrementally tighten the clamps and this usually works well enough. I would do a dry run and try this out you might be surprised that's all it takes.

Rather than making bowed cauls, the technique I like best is to place thin 2x2 pads covered in packing tape over each joint followed by a caul on top. Make the inner pads a bit thicker and incrementally thinner as you go out so the clamps exert more pressure on the middle (effectively creating a cambered caul). Any hardwood 2x2 or 2x4 on edge should be stiff enough to work.

Hope this helps. Remember, before applying glue ALWAYS do a dry clamp up!!

[Brian Runau]

Brian, Panel glue ups are a big deal for every ww'er. Don't get frustrated we've all been there. You watch the guys on YouTube do it and wonder what's wrong with you, right? Well yes, sometimes it IS the wood but with experience you will be able to eliminate problems. Learning to select and prepare the wood is where it all starts. I wouldn't worry about 1/8" bow in 60 that can be taken care of during glue up. I worry much more about grain direction and the potential for a board to cup. When that is all set, make a big triangle on the face pointing toward the front. Before I make a suggestion, let me say we've all been humbled and frustrated at some point with panel glue ups. Let me also say IMO dealing with surfaced lumber is THE biggest source because there is no extra material to work with and this really puts the pressure on for perfectly aligned joints. The best way to ease the pain is start with thicker material than the final. I also do not fret about alternating growth rings, etc. I only look at the face grain to obtain the most pleasing arrangement. A pay the most attention to the edge joints, making sure they are perfect. I am a big fan of spring joints. By flat, I'm referring to flatness across the face of the board (or cupping), not bowing. Cupping is more important because you can't reference a 90° edge off a cupped board. Often times a bow can be cancelled out by pairing it with another boards bowed the opposite way. There are two basic ways to address alignment: 1) mechanical aids such as biscuits, splines, Dominoes, etc or 2) clamping aids or 3) nothing. Personally I use a rubber mallet to tap the high spots as I incrementally tighten the clamps and this usually works well enough. I would do a dry run and try this out you might be surprised that's all it takes. Rather than making bowed cauls, the technique I like best is to place thin 2x2 pads covered in packing tape over each joint followed by a caul on top. Make the inner pads a bit thicker and incrementally thinner as you go out so the clamps exert more pressure on the middle (effectively creating a cambered caul). Any hardwood 2x2 or 2x4 on edge should be stiff enough to work. Hope this helps. Remember, before applying glue ALWAYS do a dry clamp up!! Thanks to all for your help. One joint moved some during the dry time and it is a little rack, but since ti is 60" this should not be a problem. It is a head board so fitting it in place should not be a problem and it should take the racking out of it. Brian

[Lee Schierer]

http://www.homedepot.com/p/Everbilt-1-in-x-48-in-Aluminum-Square-Tube-with-1-16-in-Thick-801307/204273940

What if i used five of these spaced across top and bottom clamped tight from the inside out with clear shipping tape between the metal and wood?

Thanks.

Brian

That tubing is going to bend too easily to be of any benefit.

[Al Launier]

A curved caul would work better. Even a bowed 2 x 4

I don't think that aluminum tubing would provide much pressure in the center of the panel. Save your money and get or make some curved cauls.

Agree with Jerry.