Our vibrocorers can be
operated with steel or aluminum coretubes with or without liners.
If the metal coretube is
intended to be used with a plastic liner, it is often difficult
to find the matching tubes and liners off the shelf, i.e. a plastic
liner with an OD smaller than the ID of the coretube (generally
by some 0.060-0.080" or 1.5-2mm). In this case the best solution
is to first select the coretube and to have the liner custom-made
to match it. Most common liners are made of polycabrbonate or
CAB (cellulose-acetate butyrate). Note that in non-abrasive sediments
a soft polyethylene tube (usually purchased in 6" wide x 1000
ft rolls) with a thickness of 6 mils
for the P-3, can be an effective, easy-to-find alternate to a
rigid plastic liner.
As a rule of thumb, optimum penetration
is generally achieved with steel coretubes in the 3.5" to 4" (8.9 to 10.2cm) diameter and 0.083 to 0.120" (2 -3 in) wall thickness. However, in similar diameter, expendable linerless thin-wall aluminum coretubes, e.g. 0.062 - 0.080" (1.5
- 2 mm) wall thickness, often are the most practical candidates
for a vibrocoring project that requires a hard case to ship samples
to a lab. Please Note: Aluminum core tubes can not be used with
the P-5. Also, some of our clients have obtained excellent results
with bare, stiff plastic Lexan coretubes, e.g. 4.0" OD. 0.125" wall,
up to 20 ft long, without any metal coretubes or conrnoses,
provided with a plastic core-catcher (orange-peel type) simply
glued inside the tube.