Rusty fastener removal tricks?

Discussion in 'Miscellaneous' started by mccloud, Jan 22, 2011.

  1. mccloud

    mccloud Wooden Canoe Maniac

    Restorers of old boats must find many kinds of very rusted fasteners, screws, nails, bolts, either original or the result of bad repairs, that have to be removed. A search of the WCHA site using the term rusty, and got only 10 hits - none of which addressed this problem....this came as a surprise. So what are the tricks for removing badly rusted fasteners while doing a minimum of damage to the wood? And how about removing rust stain on the wood? I'll start the thread:

    I have been trying to remove extremely rusted bolts (or machine screws), about #8 - 1 1/2", which have a slot head on the exterior of the hull and a hex nut on the inside. Applying a screwdriver to the exterior gets me nowhere - it's frozen solid. Using a nut driver to the nut invariably breaks the threaded portion at the base of the nut. I have tried to use a reverse-fluted drill bit on the head to see if it would grab and back the remaining bolt out, and that is unsuccessful. I have NOT used WD-40, assuming it would do no good and permanently stain the wood.

    The best solution so far has been to use a hacksaw to widen and deepen the slot in the head to accommodate a larger screwdriver, then break off the nut, then carefully drive the point of a knife underneath the head and while continuing to apply upward pressure with the knife, use the screwdriver to back the bolt out by 1/8" - which is often not easy, but just enough to grab the head with the vice grip and twist it the rest of the way out.

    So aside from drilling them out, is there an easier way? How about rusty nails and rusty screws? And does anything work to remove the rust stain in the wood? TM...
  2. Billm

    Billm Canoes & Guideboats

    An old friend who built and restored guideboats had a dentist's tooth extractor that he used to remove tacks from old planking. I never tried it but he swore by it.

    I've had good luck with some small screw extractors that I bought from Jamestown. They are similar to the ones that you can buy at any hardware store but smaller. My applications probably weren't as demanding as the one that you described.
  3. Ed Moses

    Ed Moses LOVES Wooden Canoes

    Removing rusted/corroded fasteners


    Here's a trick I believe that was on the Woodenboat forum passed on to me by my wife's cousin, a regular student at woodenboat school.

    Before doing anything to the fastener hold an electric soldering gun tip to the head of the screw or bolt/nut until the metal gets hot enough to soften the paint accumulated in the slot. Pick out the old paint in the screw slot and try a slight tightening twist first then a loosening twist to see if the heat has expanded the metal molecules sufficient to break the bond of rusted/corroded metal to wood fiber. If the screw does not move , heat it again longer this time then use a flat faced punch to give the screw head a stiff rap. This should get things moving for you. You have to proceed slowly in order not to have screw breakage and to achieve a harmonious result. I used this technique removing outwale screws on a canoe that had been used in salt water for years and all brass fastenings were badly de-zincified with zinc scale seizing the screw threads.

    With a bolt and nut as in canoe seat bolts, I heat it as described above and then using an eyedropper with just a small quantity of PB Blaster or Breakfree in it, I carefully apply that on the hot bolt threads, being extra careful not to get it on wood if possible. You cannot use the spray can of these materials without getting it on wood. This material usually sucks right into the heated threads and begins working for you loosening the fastening. A repeat of the procedure is sometimes necessary to achieve success.

    Hopelessly seized fastenings, well you will just have to break them off, unfortunately. :mad:


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