Build a house with heavy bricks.

Heavy bricks are solid bricks.

Solid bricks have a high density.

If you build a furnace you see solid bricks, otherwise molten metal might leak through them.

How so you make bricks solid?

Pour porcelain balls into a jar and weigh it.

Is it full? No, I can see spaces between the balls.

Maybe we can fit smaller balls into the spaces.

Pour in the smaller balls and weigh again.

Is it full now? Look carefully, I can still see small spaces.

Add some zircon sand.

Is it full now? We maybe can’t see any spaces, but we could fit in powder if it flowed.

Would it be full then? No, we could still add water.

Let’s try mercury (use a funnel).

Show a mix sheet.

Coarsest first.

Finest last.

This demonstration uses balls because they flow and they are very different in size, so that they can flow into all the gaps.

On the mix sheet we have all different sizes, and they are not round. We need to add water and shake them to get them to pack close together.

With more fines they flow better.

Castables have all sizes.

Ramming has more coarse.

Pourables have lots of fines.

Paints are all fines.

Plastics have flaky materials added, eg, clay, kaolin, bentonite (Eccabond).

Plasters have sticky chemicals added.

Pass around:

Lead dross

Steel

Aluminium

Rock

B6 Brick

Oil Filter

How do we measure density?

The people who invented the metric system were clever, they made the weight of litre of water to be the same as 1 kilogram.

The density of water is 1 kilogram per litre. It is also 1 gram per cubic centimetre and it is 1 ton (1000kg) per cubic metre.

The density of AOP is 1.5, so we can fit 35kg into a 25L polycan. You have notices that we can put 7kg of 3379 in a 5L bottle, or 6kg of reinite buinder. We sell our liquids by kilograms rather than litres because it is easier to weigh them, then to measure the volume.

What is the volume of this glass jar?

It would be extremely difficult to calculate it, but easy to measure it by filling it with water.

End of demonstration.