Olafur Eggertsson writes: "You should contact Thomas Bartholin in Copenhagen - he has the best corers, with prices from c.The margay is very similar to the larger ocelot in appearance, although the head is a little shorter, the eyes larger, and the tail and legs longer.This piece must have a whole through it, because you will quite often want to push the wood sample out of the corer."A little refinement on the Tucson system was an idea that I picked up from the archaeological lab in Sheffield.At periodic intervals down the bit, holes should be drilled through the walls of the corer (ca. Mine were drilled in a pseudo spiral pattern of about 7 cm distance apart.Because one is coring dry wood, there is a lot of dust that can clog the corer and sample when drilling. Be sure to smooth the burr created when making theses holes.Fresh wood can be bored more or less well depending on its nature.
They were developed by Thomas Bartholin and slightly improved by RINNTECH.RINNTECH dry wood borers can be run with commercial electric drills (600 W power).They are available in lengths of 150 mm, 250 mm and 350 mm.This is the company I use to create my custom-designed drill bits.The package comes as a three-piece kit that includes the 10" long drill bit, a polyethylene guide plate, and a sharp, curved extractor to dislodge the core from inside the wood beam.