Geology Thin Section - Fixing rock samples to glass slides

Gather together similar sized slides in thickness, you can either use our geological lapping machine or the Geoform to create a frosted matt surface on one side of the slide. This will create a bonding area and equal thickness with the sample you have prepared on the Geocut or Geoform which is cut to size. You have to lap one face of the sample using silicon carbide powder and water onto a lapping plate in a figure of eight action, again to create a bonding surface. Similarly, you can use the geological lapping machine placing your samples inside the control rings and adequate pressure weights.

We recommend the use of our proxy resin and hardener, mixed correctly to a 2 to 1 ratio resin to hardener. On a non-porous rock sample, apply the glue along one edge of the frosted side of slide, gently squeezing together removing all air bubbles.

With your glued rock sample placed onto the Geofix, leave for approximately 8-10 hours. To increase the speed of the drying time of the resin you can place on top of a hot plate set around 60°C and to increase the pressure onto your rock sample, there are four stations with an adjuster to increase.

These samples have been prepared and dried, ensure there are no air bubbles on the bottom of the glued surface on the glass slide. This sample is now ready for the next procedure on the Geoform.

For porous rock samples we have to adjust the technique of bonding, place into a rubber pot and create your mixture of resin and hardener, pour into the area and place into the Vacumet or KemVac. Once your sample is within the vacuum chamber, turn on and ensure an adequate vacuum seal has been obtained. Turn to the start position and increase the pressure to 600. Allow it to sit there for 3-4 minutes, turn the unit off, this will allow the air to escape the sample and the resin to impregnate. Turn back on, do this 3 or 4 times. After the fourth or fifth operation reduce the pressure to between 300-400 on the scale and leave to cure for up to 8-10 hours. Remove your sample from the Vacumet/KemVac and prize out from the rubber holders. Lap the base of the potted sample then mount to the glass slide and set in the Geofix for a further 8-10 hours.

This sample can then be placed either back on the Geocut or the Geoform to create the size of sample you require for the next stage.