I have a table that I bought second-hand. After a few days in my house, it began to warp. I think it may have been from temp/humidity changes. Is there a way to correct the warping? My father said if I humidified the wood and flattened it with weights and then dried it slowly, that might work. Let me know what anyone else thinks. Thanks!
You might try removing the table top and make sure it it has the same finish on both sides. If the top has been stripped and the underside has not, that can contribute to the warping. Place the tabletop cup side down on an unfinished cement floor and allow it to sit overnight. This will usually straighten the wood out but you still need to deal with the warpage. Good Luck
YOU MIGHT WANT TO TRY PLANNING THE WOOD IT MIGHT SHORTEN IT (MAKE IT THINNER) BUT IT WILL SAVE THE TABLE TOP I HAVE NEVER HEARD OF LEAVING IT ON THE BASEMENT FLOOR OVERNIGHT BUT YOU NEVER KNOW BUT IF THAT DOESN'T WORK TRY PLANNING IT IM SURE THAT WILL HELP.
The basement floor trick will work, but only temporarily until the top dries out again. The idea is to add moisture to the dry (cupped) side. Once it's flat - using this method - you could seal it and maybe it would stay flat, but it would be important to seal both sides and edges evenly. If one side is left unfinished, it will absorb and evaporate moisture and the wood will warp.
I have had success "unwarping" unfinished wood by getting the side of the board on the inside of the warp wet, and then leaving the dry side facing the sun until the board is reasonably flat....usually a matter of hours. Checking moisture content with a moisture meter usually shows no overall change in moisture content if the board was dry to begin with. This may help you if you plan on refinishing the table. Also, if the table was previously stored in a location with a different moisture content than your house, it is going to take some time to climatize to your house. If the table is placed anywhere near a heat source it won't climatize evenly and cause warping. I think I would be tempted to let the table sit for several weeks to complete the proccess. If the table was not warped before, and no parts have broken loose, I would bet it will soon settle back to its original condition
Warpage is caused by *differential* drying. Wood shrinks as it dries, thus if one side is finished and the other is not, the finished side will dry/moisten more slowly and will generally bup away from that side (most is drying.)
You can return the table to it's "flat" condition by placing it back into the same or similary temp & humidity that it had previously. Barring that if you're *patient* it should eventually reach an equilibrium state in the new environment. DO NOT PLANE IT! If you do, you'll do two things. #1, you'll destroy whatever value it has as an antique, and #2 it'll simply warp again as it reaches a steady state in it's new clime.
My guess is that the top is finished but the bottom is not and you moved it from a more humid climate to less. This causes the bottom to dry and the top to hump. Let it accimatize and it should return to being flat in a few months.
If it has no value as an antique, simply sand off the finish on both sides and let the top stand on end with good airflow to both sides. This will allow it to rapidly stabilize. Then once it's stable, finish both sides of the top equally and it should *REMAIN* flat as the rate of change of the moisture content will be limited on both sides of the top.