Screwing on a solid wood top

[Steven Hans]

That is interesting with the washboard effect. I thought by alternating the growth rings that this would not happen though.

[Richard Dooling]

As I mentioned there are different opinions about this. As you may have noticed woodworkers often tend to be a tad opinionated. What’s the best way to sharpen and hone a blade? Should I cut dovetail pins or tails first?

I don’t fret over this stuff too much – but I try to be aware of the dynamics involved. The “wash board” effect would probably be most pronounced when gluing up wide flat sawn boards. It may be advisable to glue up a lot of narrow boards flipping the ring pattern.

There are many factors to consider including:

Grain direction is important if you are going to plane the glued up panel.

Different species of wood have different characteristics as regards movement.

The particular board you are working with. Even different boards from the same tree may act different. Many people rough mill a board and sticker it to let it reach a new equilibrium before proceeding to final milling.

The area you live in – maybe it’s so dry that you do not anticipate cupping will be a problem.

Cupping may not be your main concern. If you have two boards bowed along their length you may want to flip one so it helps control the bow in the other.

What looks best may be the ultimate decider. All heart wood up?

In the end there are so many factors that you can’t have a check list – IMHO you need to understand wood and it’s dynamics. I’m still in the steep learning curve and have so much to learn. I suggest R. Bruce Hoadly’s Understanding Wood: A Craftsman's Guide to Wood Technology. Again – I never worry about this so much that woodworking stops being enjoyable – I’m just trying to understand my material.

Here is an interesting tool to help estimate wood monement.
http://www.woodworkerssource.com/movement.php

[Bill Keehn]

Forgot to mention, the boards are around 4-1/2" wide to make a top that is 18-1/2" depth and the width is 21". I followed the Wood Store plans closely, but did read that it is best to have your boards around 2-1/2 to 3" somewhere to remove any issue of cupping. And the holes in the back are elongated! 1/2" slot actually with a 1/2" wide counterbored slot for the washers.

If it were me, I'd be focused on which face of the board looks best and how well the grain matches. If I'm going to compensate for cupping, I'd rather modify the construction in a way that doesn't place aesthetics second.

I'm a little suprised nobody asked this, but did you finish the underside of the tabletop too? You can greatly reduce the amount of moisture aborbed by the wood by finishing both sides. Try removing the top and let it sit out in the sun with the underside exposed to see if it flattens out again. If it does, put some finish on it. If that doesn't work, consider ripping a series of kerf cuts on the other side so that the top can easily be flexed. Then you should be able to flatten it and use battens to reinforce the top and keep it flat.

you could fasten a batten under the top inside the stretchers to pull it into place. put your screws in the batten in the middle and don't fasten the ends.

I think better still, instead of screws, use a sliding dovetail. This is something I saw on the seat/lid of an antique piano bench I once owned. When I first saw it, I thought it was a very clever idea for strengthening the seat and keeping it flat. Also, I am sure it made alignment of the boards in the seat much easier during glue-up. Of course, this won't work if the top is already cupped. You need to flatten the top before cutting the dovetail slots.

On the bottom side, route a pair of dovetail slots, across the grain about a 1/3 from each end of the top, starting at the back. Stop the slot before exiting the front. Then using scraps the same thickness as your table top, rip battens to fit the dovetail slot, adusting the blade pitch to the dovetail angle. You can adjust the thickness and width of the dovetail to get the strength you need. It should be a snug fit, and you'll need to tap them in place. A little bit of glue at the blind end of the slot should be all you need to hold them in place.

[harry strasil]

Sliding dovetails was how all 3 battens were fixed to the top of this wedding chest, the outside battens are also the hinges. No metal used in its construction.

[Bill Keehn]

Sliding dovetails was how all 3 battens were fixed to the top of this wedding chest, the outside battens are also the hinges. No metal used in its construction.

Good example! I like it. What's it made from?

On my piano bench, the battens were not as thick as those. The craftsman had also rounded over the edges that stood proud and had chamfered the ends. I think the chamfering had been done so that the batten could continue out past the edge of the "chest" part of the bench without preventing the lid from closing.

Even with the chamfer, the battens still stood slightly proud and it was these that made contact with the chest when it was closed. This caused an eighth inch gap or so under the front lip of the lid. I don't know if this was done to fine tune how the lid fit between the side pieces, or if it was to prevent little fingers from getting crushed. What I do know is that the thing held up really well.

[harry strasil]

the frame is salvaged Burr Oak from a corncrib, they were grooved with a stanley 45, the panels were a board that was stained, either from chemicals from the ground while growing or spalted, no one wanted it so I got it cheap, the panels were all raised with a woodie panelraiser. The top is some old barnboard I bought at the lumber yard years ago, the battens each have one 1/4 dowel on one end to keep them from sliding out should the material shrink, the hinge pivot are also dowels. Something I really didn't want to do, but a good friends daughter requested that I make her a wedding chest for her wedding present from Mom and Dad. I gave them a bag made from an old sheet that was full of cedar chips, I had originally wanted to make the panels from cedar. Its their pride and joy I think, her dad told me they use it for a centerpiece/coffee table in their living room.

[Steven Hans]

I did finish both sides. I have some pictures so you can see the top on the nightstand. Please note that I built this from plans and it is the first project I have done. I built shelves and drawers for my garage, but felt it important to follow plans as written for my first project.

[Bill Keehn]

That looks great Steven. Pretty impressive for your first project. I see the wood movement you were talking about, but I honestly wouldn't have noticed it if you hadn't mentioned it.

[Steven Hans]

Thank you Bill. I don't think I am too worried about the top because when I was placing into position I actually was able to nudge the top on the nightstand. I then nudged it back into position. Would this be a good check to see if the top is screwed on too tight? Or perhaps there could still be problems of wood movement. Bill, I should mention that I took the photo at an angle that really accentuates the flaw. And this is towards the back.