Compression strength test for moulding sand

1. Take weighed proportions of sand and clay and dry mix them together in a Muller for 3 minutes.
2. Adjust the weight of the sand to get standard specimen
3. Remove the standard specimen by the stripper and place it between shackles which are fixed in the sand testing machine.
4. Rotate the handle of the testing machine to actuate the ram. Thus, hydraulic pressure is applied continuously till the specimen raptures.
5. Read the compression strength from the gauge and record the same.
6. Conduct the experiment for the above said two cases and tabulate the result.

Tensile strength test of core sand

1. Take proper proportions of base sand and binder then mix them together thoroughly.
2. Assemble the core box and fill the mixture into it
3. Place the core box under sand rammer and ram the sand thrice
4. Using a wooden piece tap the core box gently from sides. Remove the core box leaving the rammed core on a flat metal plate
5. Bake the specimen (which is on a plate) for about 30 minutes at a temperature of 150^oC – 200^oC in an oven. (When the binder is core oil)
6. If the binder is sodium silicate, pass Co₂ gas for 5 secs. The core hardens instantly and the core can be directly used.
7. Fix the tension shackles on to the sand testing machine, and place the hardened specimen in the shackles
8. Apply the load gradually by turning the hand wheel of the testing machine. Note down the readings when the specimen breaks.
9. Repeat the procedure for the different percentage of binder and tabulate the readings

Shear strength test for moulding sand

1. Take weighed amount of foundry sand (mixture of sand, clay & water as specified).
2. Transfer the sand mixture into the tube and ram it with the help of a sand rammer thrice.
3. Fix the shackles to the universal sand testing machine
4. Remove the specimen from the tube with the help of a stripper and load it into the universal sand testing machine.
5. Apply the hydraulic pressure by rotating the handle of the universal sand testing machine continuously until the specimen ruptures.
6. Read the shear strength directly from the scale and tabulate the readings.