Shipwright Alan Campbell passes on a useful tip to help deal with a broken screw

Briskly tapping a screwdriver’s handle with a small hammer will usually loosen a stubborn screw, then a steady pressure should shift it. But what if the screw breaks off?

The portlight frame screws had been doing their job for 50 years, but the red lead-putty seal had finally started to allow drips inside and one of the brass screw-shanks was almost corroded through. Replacement with bronze screws was the plan, but first I had this broken off screw in the way. So what to do?

Using a 10mm drill, I centred this next to the broken brass screw and drilled it out with the rest of the hole, to the depth of the screw shank. The steel drill will cut the brass screw easily. Next, a 10mm teak plug was glued and tapped into place (use a piece of hardwood between the mallet and plug to avoid breaking the plug). Once the glue had set, I chiselled the plug off and sanded it flush. The repaired spot was now as strong as the original.The portlight frame was offered up while the new hole for the fixing screw was marked and then drilled. This is a simple, permanent repair calling for just a spot of common sense and proficiency with simple tools. It’s also better by far than the all too frequent ‘gouging out and bodging up with plastic resin’ routine. Most tired or ruined screw holes in wood can be repaired by the method described.

The job of reseating these portlights, with red lead-putty again, was going well until one screw refused to give up its near 50-year-old grip, and sheared off flush in the wood

The job of reseating these portlights, with red lead-putty again, was going well until one screw refused to give up its near 50-year-old grip, and sheared off flush in the wood

A twist drill was centred at the side of the soft brass screw, and a hole drilled for a shipwright’s standard 10mm teak plug. This was then glued and tapped into place

A twist drill was centred at the side of the soft brass screw, and a hole drilled for a shipwright’s standard 10mm teak plug. This was then glued and tapped into place

 

 

The plug was chiselled off and sanded flush, then drilled for the new screw

The plug was chiselled off and sanded flush, then drilled for the new screw

The job done, good as new and ready for the next 50 years

The job done, good as new and ready for the next 50 years

Alan Campbell

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