Fire and Ice:

The Nuts and Bolts of Freeing Hopelessly Stuck Fasteners

If you work on a boat you already know nuts and bolts freeze with frustrating frequency. Sometimes it’s a carbon steel bolt corroded solid on a cylinder head. Other times it’s a stainless steel bolt stuck n an aluminum lower unit. No matter. The only way to break it loose is with patience, bloody patience. Count to ten. Swallow the frustration. Then, one by one, follow the timeworn remedies revealed below that have been passed on from the dawning of the Iron Age.

But whatever you do, don’t make the mistake of trying to free a bolt with brute force, especially one stuck in aluminum housing. Otherwise it may snap off further complicating matters. It’s a better strategy to walk away form a job for a day or two than risk making the situation worse. Besides, it’s almost karmic the way coming back to a job after even a short break seems to make things go more smoothly.

Begin with fire. An oxy-acetylene torch works best. The downside, if you don’t already own one, they’re expensive to rent and complex to fire up. Thankfully, the flame blossoming from the common propane torch may hold enough BTUs to get the job done. Either way, oxy or propane, heat the bolt. No need to go red-hot, but hot enough so droplets of water flicked onto the bolt sizzle off  into a vapor.

The most important step: Let the bolt cool completely. On a hot summer’s day that may mean a wait of at least an hour. The reason this method works isn’t because heat breaks the fastener loose. But rather, it’s the expanding and contracting of the hot and cold cycles that breaks corrosion’s hold on the threads. One, twice, even three applications of heat may be required. Like we said in the beginning, patience is a virtue.

An alternative to fire is its opposite number: ice. Some mechanics claim dry ice will shrink a bolt enough to break corrosion’s hold. Though admittedly, most of us choose a torch because it’s quicker if not more dramatic. Besides dry ice, another cool option is cold in a can. Essentially it’s an aerosol spray that freezes metal ice cold. Again, apply the cold, and then wait for the spring thaw, so to speak.

Purely mechanical methods are also effective. The most common is to drill a hole in the bolt head, from the top down, a bored tunnel paralleling the threaded shank. Thread an extractor bit into the hole until it bottoms out. In effect the bit becomes a new bolt head, one you can really grab hold of. Because its threads are left hand, cranking counter clockwise on the extractor grips the bolt tighter and tighter.

Sometimes the corners of bolt head round off making it impossible for a wrench or socket to grasp hold. Calmly reach for a center punch and a ball pein hammer. Pein the metal, expanding it outward, forming new corners in the six-point star that a wrench can grab hold of.

Depending on what parts the bolt holds together, consider drilling a rescue shaft at an angle in order to reach deep in the threads. The drilled hole lends access to the threads so they can be soaked with penetrating oil, coca cola or any other concoction you have faith in. Obviously this method is not available where drilling would destroy the very parts you’re trying to remove.

Never use force. Just get a bigger hammer. When you are willing to sacrifice the bolt, position the wedge tip of a cold chisel against the corner of the bolt head or nut and bang away with repetitive strikes of a ball pein hammer. Strike the chisel so the impact forces the bolt head counter clockwise, loosening it. Wear leather gloves to protect your hands.

Finally, assembling fasteners with anti-seize compound in the first place is a good way to keep fasteners from corroding in the first place.