Removing super glue can be a real headache for the same reason the stuff is usually so useful: it's a powerful adhesive that forms lasting bonds. In most cases where super glue gets on surfaces by mistake, acetone is the go to solution because of the way it breaks down the glue.
However, wood surfaces present a unique challenge when removing super glue because it is porous and can soak up the acetone, causing permanent staining and discoloration. You need to be careful when applying any type of solvent (acetone or otherwise) to your wood surfaces, as they can permanently stain or destroy the item even worse than the super glue.
Here are some strategies to remove unwanted adhesive and spare the integrity of your wood at the same time.
1. Small, Repeated Doses
Since using straight acetone can be more damaging to your wood than simply living with a hardened dab of super glue on it, try cutting the intensity of your acetone by mixing it with water. Next, using cotton balls so that you can control the amount of liquid that actually comes into contact with the glue and the wood, dab or rub at the glue multiple times.
By design, this method is slow and steady, so do not expect the glue to loosen, soften, or come away all at once. Wait a moment for the mixture to do its work, and then with a dry cloth, wipe up any excess acetone mixture. Replenish the cotton ball with a fresh dose of acetone and water, and then repeat what you've just done.
While the chances of this technique working will vary based on the situation, it gives you a good shot in that you're still able to use acetone but in small enough batches that it won't hurt the surface.
WARNING: Acetone is a common ingredient in paint thinner and will destroy the painted finish when used on wood, even in small doses
Scraping Loose Glue
Once the glue does begin to soften, attempt to wedge a small edge or spatula between the loosening spot and the wood. With any luck, the glue will lift off, leaving behind a small amount of residue. If the wood surface is unpainted, try oils to help lift the glue and help wipe away residue.
2. Apply Controlled Impacts onto the Glue
In certain cases when super glue drips or spills onto wood, the shape of the actual hardened glue can be quite thick. This can actually be a good thing. Despite the large amount of glue that may appear to be on your wood item, if the glue takes on a thick, bubble-like shape, then the actual amount of glue that's in direct adhering contact with your wood is minimal.
Try to moisten the super glue with light amounts of acetone or water as mentioned previously, and when the glue softens, try to tap it loose with a flat hammer head or similar object. The pointed edge of a meat tenderizer could also do the trick. The point is to loosen or stress the super glue so that it lets go.
Repeat the process, exerting caution to avoid permanent damage to your table top. Check it as you go, chipping away at its grip on the table surface until you can remove the bulk of the mess.
3. Mix in WD-40 or Dishwasher Soap
This strategy is best for surfaces that won't actually be seen. For example, if you were using super glue to attach the ends or edges of a book shelf or to create another kind of wood joint and you accidentally put glue on the wrong spot or attached the pieces poorly, you'll need to break the adhesion and remove the glue.
Adding a small amount of WD-40 or dish washing liquid to your acetone will accomplish this easily. It will likely leave some level of discoloration, but if you're going to be regluing that edge anyway, this won't matter.
4. Residual Super Glue Cleanup
Once you have the bulk of the super glue removed, you can try to get remnant imprints of it from the wood's surface with more acetone. Be aware that since you'll only be working against the glue's residue and not the glue itself, there is a higher chance that more of the acetone will come into contact with more of the wood. So, work carefully and do not be afraid to try more than once with small amounts of solvent.
Whether you're successfully able to remove all stains and residue or not, wash it out on a varnished or oiled table top by adding some sealant to a rag and rubbing it in. The oils will generally wash into the wood and can actually hide or cloak the stain.
Mineral oil works really well on surfaces that have not been painted and will assist in the surface appearance on varnished items. Simply rub the oils in thoroughly to get a good even coat and allow it to dry. Your wood surface will be back to normal in 24 hours.