BOT/MBIO/ZOOL 5364

MAKING KNIVES WITH THE LKB KNIFEMAKER

For detailed illustrations, see “The LKB Knifemaker 7800B” at URL: http://bomi.ou.edu/bmz5364/knife-maker.html.

I. Clean glass strip with lukewarm soapy water, rinse thoroughly with distilled water, and dry carefully with a paper towel. For subsequent handling, hold the strip with a Kimwipe.

2. Making glass squares (see diagrams)

a. Break a full sized strip in half, lining one end of the strip against the dot (14a) on the cover plate. The rippled edge of the strip should be placed face down.

b. Line one end of a half-strip against the arresting stud (29).

c. Lower clamping head (8) onto strip with locking lever (2). Strip should not move when nudged gently with your finger.

d. Set score selector (13) to the setting indicated on the right. Pull scoring shaft (15) toward you.

e. Break square by turning the breaking knob (18) clockwise. When the glass breaks immediately return knob to its fully counter-clockwise position.

f. Lift clamping head, assisting with your hand, return scoring shaft back in, and remove the glass square with fork (1). Remember which corner is the lower left one.

3. Making knives

a. Put glass square on top of breaking pins (26), inserting lower left edge between white guiding rings (22a) of front glass holder (22). Lower rear glass holder onto upper left edge of square by pushing in and turning counter-clockwise to disengage the knob (31).

b. Lower clamping head onto square.

c. Set score shaft selector control to 25.

d. Score the square.

e. Move the damping pad (23b) with lever (23a) up to lower left edge of the square so that it is pushing on it lightly.

f. Break the knife square into two knives by rotating breaking knob (18). Return knob to fully counter-clockwise position.

g. Move damping pad to it original position.

h. Lift clamping head while assisting the head, and remove knives with the fork. Do not touch anywhere near the knife edge.

4. Putting boats on knives

a. Cut a small length of aluminum tape and attach squarely to one edge of boat and wrap around to the opposite end as indicated in the following drawing.

b. Remove excess tape with a razor blade or by carefully tearing across the back of the knife.

c. Seal the bottom edges of the knife using hot Pyseal and a paint brush. Pay particular attention that the bottom of the knife is well sealed.

5. Checking knives

a. View the glass knife with a dissecting knife. A good knife for thick sectioning has a large edge with no spur, or a small one.

b. For either thick or thin sectioning, examine the knife edge directly to locate any edge imperfections, whiskers, contamination or fingerprints on the back of the knife.

c. For thin sectioning, bounce light off of the front edge of the knife. Any lines running parallel to the stress mark which sweeps from the left may result in knife marks. The best knives do not show this artifact.

d. The sharpest edge is to the left generally. The most durable surface is to the right (but left of the whiskers.) See drawing.