Wednesday, March 30, 2011

Security Lock for Portable Computer

Leave your laptop/notebook/netbook computer unattended and you may well become a victim of "grab and run", the most common kind of computer theft, which can happen even when you are using it. Portable computers are a tempting target for thieves because they are so easily fenced.

To prevent this kind of theft, pretty much all portable computers have a Kensington Security Slot, a small reinforced hole for a locking mechanism that looks somewhat like but a bit smaller than a USB slot.

A variety of computer locks are available ranging from complete junk to complete overkill. A good balance of function, security, and convenience is the Targus DEFCON CL PA410U, which features a 4-digit combination lock (no key to lose) that you can set to the combination of your choice. (It won't stop a determined thief with heavy bolt cutters, but pretty much nothing will.) Find a good price with Google Shopper.

IMPORTANT UPDATE: Due to serious deficiencies, I now rate the Targus DEFCON CL PA410U unacceptable -- see A Tale of Two Locks.

Tuesday, March 15, 2011

Knots Every Sailor Should Know

Alpine Butterfly
These eight knots will cover 99% of your marine knot needs. [click links to more information and instructions on how to tie]
  1. Alpine Butterfly (animation)
    Strong and secure, will not shake out, will not jam, better than bowline. Use Method #4 (video) instead of Bowline.
  2. Bowline (animation)
    Strong, easy to tie, but can shake out if not locked.
  3. Buntline Hitch (animation)
    Great knot for halyards, securing fenders to lifelines, etc, but can jam.
  4. Cleat Hitch
    Use for securing ropes to cleats.
  5. Figure Eight Knot (animation)
    Good stopper knot, can be adapted for other purposes.
  6. Gripping Sailor's Hitch
    Great for securing one rope to another rope under load.
  7. Slipped Half Hitch
    Quick-release knot for sail ties and bags, not secure. Also useful as temporary stopper knot; e.g., for spinnaker sheet at a block (animation).
  8. Square (Reef) Knot (animation)
    Famously used for tying reef points in sails.
Sheet Bend is deliberately omitted because it's weak and unreliable.
Two Alpine Butterflys tied together or two bowlines tied to each other (Bowline Bend) are better alternatives, or for ropes of roughly similar thickness the Alpine Butterfly Bend

More Knot Resources

Monday, March 14, 2011

Carbon Fiber Spinnaker Pole Repair

When our 14-foot carbon fiber spinnaker pole snapped (due to excessive lateral loading) and we were confronted with a very expensive dilemma (a thousand dollars for repair by professional riggers or thousands of dollars for a new pole), we managed to repair our pole ourselves, quickly and much less expensively, by means of a repair tube custom built for us by Jeffery Kent of Composite Solutions Inc, who:
  • promptly built a 3-foot carbon fiber tube to match the outside diameter of our pole,
  • machined down the ends to match the inside diameter of our pole,
  • leaving a center section to replace the broken pieces we cut away from our pole, and
  • rushed it to us by air.
We bonded the two pieces of our broken pole with epoxy to the machined ends of the custom repair tube, and the resulting repaired pole both looks and works great. (To complete the repair we will wrap the repaired area and clear coat to protect it.)

Highly recommended.