Fasteners that can't be unscrewed can frustrate even the most seasoned builder or engineer, but before you throw a wrench at the wall in desperation, try some of these tips to loosen that stubborn bolt.
Take a step back and try to understand what the problem is. Has the fastener rusted? Pieces don't match? Or was the clasp just too tight?
If the blanks don't match, try moving them around to straighten them out. Ideally, they should be in the same position relative to each other as when the bolt was installed. Often the angle of the blanks was changed, locking the bolt in place.
Try using a stronger wrench. Ratchet wrenches are often weaker than their non-ratchet counterparts, and wrenches with thicker jaws are also stronger. A 6-point wrench or open end wrenches are best because they have a better grip on fasteners than 12-point profiles.
Rock the wrench back and forth, trying to turn it clockwise and then counterclockwise. This may loosen the components, and this will be enough to open the clasp.
If the clasp is slightly rusted, you may find that a drop of penetrating oil left to soak will loosen the corrosion and allow you to unscrew the clasp.
If it still won't budge, try using a breaking bar. Breakers are long, socket-ended rods that provide more leverage and fastener force than a wrench. If, when you turn the crowbar, the clasp starts to feel a bit springy and "soft", then the clasp is likely about to break. Jiggling the wrench (as above) is the best way to prevent the fastener from breaking.
You can also try using an extension cord. These are special rods that fit over the end of a wrench, lengthening the rod so more leverage and force is applied to the fastener. It is not recommended to use two wrenches to lever each other as they are very easy to break.
If the corrosion is extensive, use a wire brush to remove the worst areas of corrosion around the fastener. Be careful not to damage the surface of the workpiece. Vinegar or lemon juice and salt left for several hours or overnight can break down rusted material, making it easier to remove. Once the worst is gone, use a penetrating oil as above.
Using a blowtorch to heat a fastener and then cool it down can break down rust around components because the metal expands and contracts. This method reduces the hardness of the bolts and is obviously not recommended for use near flammable materials.
If the clasp still hasn't moved, make your own penetrating oil. A mixture of half automatic transmission fluid and half acetone creates a very penetrating mixture that you can leave for several hours before trying again with a wrench or breaker.
When using these methods, remember that it is easier to replace the clasp than the blanks, so if you need to damage the clasp, do it!
