Coffee Table top question

Your observation of the bottom being unfinished explains why the top is bowed. Uneven exposure to changes in humidity. Once you get it flat you will want to finish both sides evenly.

As for straightening it, I have not found anything that works all the time. I don't think spraying water will help. I would try scraping all the finish off the top, then leave it out overnight on your lawn, convex side down, to absorb some moisture. Bright and early next morning, lay it in the sun on a bench or sawhorses with the concave side down, convex side up. You should see some movement during the day. Watch it and flip it over if it gets near to flat to even out the drying. It might take a few cycles to get where you want to be.

Now after that fails, and I'm guessing it will but it's worth a shot and won't hurt anything, you can rip down the glue joint on every strip. Let the strips sit for a week to acclimate, then joint the edges to get them square again. Then glue the piece backup and finish both sides. You will end up with a top smaller than before in one direction, so hopefully the table is designed with overhang and the difference won't be noticeable. You could add another strip of Oak if you can find stock with matching color.

Lastly, you could just make a new top.

Without any comment on the merits of the methods suggested I would point out that when wood absorbs moisture it causes the cells to swell. If the absorption of moisture is uneven the side taking in the most moisture would expand causing the stock to bow away from that side.

In other words the convex side would be the side with excessive moisture and if you were to try the "laying it on the lawn method" one would want the concave side down so it has a chance to equalize (take in more moisture) and have it's cells swell forcing the stock, hopefully, flat again.

I would opine that if one wanted to flatten out such a board/panel, putting it somewhere that has good ventilation and stable humidity then stickering for good circulation and waiting to see if it flattens naturally would be better then force feeding it and not knowing what it will do when it again reaches equilibrium.

Awe shucks. Go ahead and comment. I don't expect it to work either.

If the

True, however in my experience drying a surface in the sun has a more dramatic affect than the opposing affect of laying the piece on the lawn. Thus, leaving the piece overnight to absorb water in the convex side will possibly only slightly increase the warp. However when placed out to dry I have seen pieces move rather dramatically. No idea why.

On the other hand, if one method makes it worse, just flip it and try the other way. I guess the worst that could happen is the moisture would cause the glue joints to fail. That might be a blessing since you won't need a saw kerf to move to option 2.

Since it is an existing piece, I assume with some age, it has been experiencing good ventilation and stable humidity for some time. I don't see that letting it sit around with stickers is going to change anything.

I think I was pretty clear that this was a long shot. But I don't think there is anything to lose by trying it.

You're right of course, up or down it's a shot in the dark.

Again your correct but actually I took into consideration that it was an existing piece with good circulation and don't hold much hope it will cure itself either. However it's the least possible destructive chicken soup method and I was kind of counting on the possibility that the poster had maybe taken the piece apart at some earlier time and left the top laying around, say in the cellar on the concrete.

Take care