Wood warpage on cribbage board theory

[Tom Moll]

Stung again by anisotropic properties of wood! :)

I made 13" diameter cribbage boards with 3 track holes around the perimeter. 7/8" thick, stable and dry cherry. Finished with 6 coats of waterlox. I wanted to speed the drying of the final coat and darken the cherry a bit so I put it out in the sun for about 6 hours. When I went to finish it up there was a huge concave bow to the wood. Maybe 1/4" or more. It was astounding. I put a damp towel over the front (hole side) and steamed it with an iron and it returned to a fairly flat position. I don't know if it will stay.

Here's what I think happened... The wipe on finish covered all sides of the board but likely didn't get into the holes. I didn't want to clog the holes and have the pegs not fit. There is probably a lot of surface area that isn't finished if you consider the surface area of the hole x the number of holes. The sun sucked a little of the moisture out through the unfinished holes and curled the board. When I put steam back it, it flattened.

Has anyone had a similar problem? How should I solve? Would a spray overcoat get in the holes? Brush a coat into each hole?
I've made a dozen or more of these as gifts... they may all be warped depending on the humidity change.

[Mel Fulks]

If you “use the sun “ you have to be careful to turn it ,probably at least every 1/2 hour.

[Jonathan Jung]

Trying using a q-tip or similar, soaked in a very thin sealer, such as Osmo Extra Thin, to seal the inside of the holes. Or spray it in. If the product is thin so it won't clog the holes much.

[Richard Coers]

Were the backs of the boards on a flat surface with no air movement? If so I suspect it was just the super heating of one side that did the deed. If dry and stable means something like 12% like it is in my region, you probably took that one side much lower in the heat.

[Scott T Smith]

If you laid the boards on grass lawn they could have absorbed moisture on an unfinished bottom side, causing the cup