Fixing a pulled screw

 I pulled a screwed-on kayak handle out of a kayak recently and need to reinstall it. Very little damage was done to the wood, but the screw threads aren't holding very well anymore (obviously). I'm thinking of filling the holes with fiberglass resin mixed with silica and redrilling it.


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RE: Fixing a pulled screw

   Is the handle mounted in a place where you could use a machine screw thru the hull with a nut on the inside?

RE: Fixing a pulled screw

as moonchaser suggests above, getting behind it with a washer and a bolt is best.

drill/fill/drill is how you should make your hole (drill the hole twice the size needed, fill with epoxy/cabosil) and then the drill the final hole through the epoxy.

there are a couple tecniques that can be used to re-bed a wood screw.

if the current hole is deep enough theat all the treads are in the wood (e.g., you are screwing into a block or a sheet that is thicker than the depth of the screw), i would fill the hole with a wettish epoxy cabosil mixture.  this should reinforce the wood in/around the hole, make it hard/strong less easy to rip out.   after the epoxy starts to cure -- when it is sort of a jello state...(still wet to touch but clearly starting to harden), i would gently but firmly screw the screw back into the hole and then back it out.  this has the effect of 'tapping' the wood-wet-with epoxy so that the threads have something to dig into.   when it is now more firmly cured but not totally cured.  do this again to confirm the tapping.  then let have its final cure.   this is often a very satisfactory/strong repair.

if the current hole is not deep enough such that the end of the screw is punching through the material, there is a different approach.   in this approach you take a simple green ear-protector or similar open sponge material to use as a plug.    the plug material needs to be longer than the depth of the screw.   this material is then soaked in epoxy, then sqeezed down to fit into the screw hole (which may have to be enlarged).  as the material is pushed through the hole (not all the way...but level/slightly proud of the outside hole).  what happes is that it expands on the other side (blind side) and now provides material  to sink a wood screw into once the epoxy is cured.   for this technique, you will want to practice with a piece of scrap to see/confirm how it all works.

final approach is to get rid of straps and clean up the old hole and drill holes for rope loops and put toggles on the boat.

others i suspect will also have creative ideas.

 

 

RE: Fixing a pulled screw

just a quick clarification on above.  if i am trying to repair the threads in the wood...i would not drill/fill/drill.  that was meant to describe what i would do if i tossing the wood screw and replacing with a bolt.

drill/fill/drill does not work well with wood screws unless you have a way of 'tapping' the epoxy to create threads that can hold the wood screw.  soft woods, by their nature are self tapping.  hardwoods and blocks of epoxy don't really work that well with wood screws becuase it is so hard, that you have to drill a hole the size of the threads to get the screw in...and now there is nothing left for the screw to 'bite' into.

RE: Fixing a pulled screw

   Get machine screws instead of wood screws. Drill to 90% of screw thread diameter. Put a couple drops/half fill with slightly thickened epoxy in the hole. Spray the screws with Pam (cooking spray), and drive into wet hole, tightening only gently.

(above for somewhat lightly loaded fasteners, like a kayak handle. The additional epoxy filled annular surface provided by going from screw minor to major diameter is usually good for almost double the load capacity.)

RE: Fixing a pulled screw

The machine screw also works well with hardened epoxy that has not achieved its full cure, usually 1 to 3 days old. Then you just treat the epoxy plug as if it was wood - drill a pilot hole and drive in the screw.

BTW, rolled up fiberglass is more dignified than an earplug (and you don't have to clean the earwax off, either) :-)

Laszlo

 

RE: Fixing a pulled screw

   I would look at use nuts and bolts through the deck with a backer board and washers between the deck and nut. I would also use the drill and fill method and use silicon caulk to seal the the hole on the top of the deck.

The purpose of the drill and fill is to seal the plywood and glass cloth from water intrusion. The caulk is just insurance.

 

 

 

 

RE: Fixing a pulled screw

   Like George was saying about a backer plate, these are inexpensive and you can just drill holes as needed for your spacing:

http://www.duckworksbbs.com/hardware/rigging/rl320/index.htm

 

RE: Fixing a pulled screw

   Nuts and washers inside the very bow/stern of a kayak? Your arms might be a foot longer than mine...

"if you don't trust glue, this might not be the boat for you..."

if this is really through a single thin skin versus into an end pour or sheer clamp, then a much bigger backing plate is called for. In that case, a rectangle of G10 (or home made e-plate) works nicely, and can be drilled and tapped after gluing to the underside of the deck.

a trick is to push a string though your deck mounting hole, thread it through a small hole in your backing plate and knot it, butter your backing plate, and then pull the string to bring the backing plate into place. Later, judt drill out the string as you begin cutting for threads.

RE: Fixing a pulled screw

A ratchet and socket on the end of pole to hold the nut and washer. The screw is tightened form the top with a screw driver. One can get pretty far into the bow/stern through the hatch.

One could also add backer blocks before the deck is affixed.

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