Replacement Caps and Bopper Maintenance

These “copper boppers” are weight forward, lead filled, copper cap billets of a type most popular with modern knappers. As with all hand tools some practice will be required to obtain proficiency. To prevent excessive pitting and premature wearing out of the copper cap learn to hit with just enough force to detach the desired flake. Naturally your billet will last longer if used against softer heat treated stones, but sooner or later the cap may need to be dressed, or re-shaped. If you feel that it has become to “nicked” to work well on softer materials and crushing of a properly prepared edge has become a problem you may file the surface of the head a bit to remove some of the roughness. However, keep in mind the fact you are removing copper off the thin cap. If the cap has become deeply pitted, cratered, or a noticeable incurvature has formed just below the top of the cap’s head, these deformities may cause enough deflection of the force that bad flakes will occur regardless of how carefully the preform’s edge has been prepared. In this case the hemispherical shape of the head may be somewhat restored by hammering. When lead finally starts to show it is time to replace the cap by following the instructions below.

1. Apply heat to the cap with a small propane torch. Use just enough heat to melt the glue without burning the wood, however some scorching may occur. When you start to smell the glue the cap should come off easily when grasped and twisted with pliers. Eye and hand protection are recommended while performing this operation. 

2. Sand the inside of the new cap to prepare a clean, ruff surface for both the lead and the glue to adhere to. Now, melt the lead out of the old cap and let it pore into the new one. Make sure the new cap is held level by another set of pliers or placed in an indentation in the ground. Also, to insure a good bond between the cap and the lead continue to heat the cap until the lead is liquid enough that it lies flat in the cap. Note: If some lead has been lost in transfer more may added. A split shot sinker, or two, might due. 

3. After the cap has cooled to room temperature liberally apply epoxy glue to the inside rim of the cap including the lead in the bottom. Replace the cap on the handle making sure it is fully seated, and then wipe off any excess glue. For best results use 30 minute epoxy and let cure overnight.

Replacement caps are available here! When ordering your tools you might want to consider adding an extra cap or two, especially for the small 3/4, and 1 inch sizes. These see the most action!       

This product was added to our catalog on Sunday 23 February, 2014.

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