Curious in the shed

[Simpo Two]

I went to cut a sheet of foamex board in half on a table saw, and drew a pencil line where I wanted to cut it.

I offered it up to the saw, and started the cut, and suddenly noticed the pencil line had disappeared! Was I cutting the wrong side by mistake? Closer examination revealed a very thin line of white dust on the line, about 1mm wide, completely and perfectly obscuring it.

Foamex dust and static electricity I guess, but why was it attracted to the pencil line? Is graphite something to do with it?

[Gandahar]

Simpo Two said:

I went to cut a sheet of foamex board in half on a table saw, and drew a pencil line where I wanted to cut it.

I offered it up to the saw, and started the cut, and suddenly noticed the pencil line had disappeared! Was I cutting the wrong side by mistake? Closer examination revealed a very thin line of white dust on the line, about 1mm wide, completely and perfectly obscuring it.

Foamex dust and static electricity I guess, but why was it attracted to the pencil line? Is graphite something to do with it?

Graphite doesn't attract things through static as far as i know. Polystyrene does, which is similar to foamex? Polystyrene is very susceptible to it, hence why when you take something out of that new delivery from Amazon all the packing pellets get stuck to your hand and it looks lyou have been fondling the sugar puff monster.

Given that, and I am no expert, I don't think so. Perhaps random chance or the human mind caused it ?( see QUANTUM CONSCIOUSNESS thread)

Talking about attraction in the shed, my wife got off with my best mate at college in a shed just outside Watford before we started courting.

At least I was warm in the house during the party, is all I can say.

[Simpo Two]

Gandahar said:

Given that, and I am no expert, I don't think so. Perhaps random chance or the human mind caused it ?( see QUANTUM CONSCIOUSNESS thread)

I think it can only have been the graphite - it's very conductive so perhaps the static concentrated on it, like iron filings in a magnetic field.

[karma mechanic]

The pencil line would have been a very slight groove. The vibration may have caused the dust to move around the surface but settle in the groove.

[Tempest_5]

I've noticed that sort of thing cutting wood. I always put it down to some sort of standing wave being setup by the vibrations of the saw.

[Gandahar]

For the last answers and also




to the original poster for noticing it too!

This is armchair science for laymen at it's finest. See, puzzle, think.

It does not even matter if we are all wrong. Newton would be proud !

Edited by Gandahar on Friday 14th February 13:54

[popeyewhite]

karma mechanic said:

The pencil line would have been a very slight groove. The vibration may have caused the dust to move around the surface but settle in the groove.

I quite like this. It comes from the 'for every action there is a bloody obvious reaction ' school of thought. Similarly perhaps in drawing the pencil line heat was created and this burnt a groove?

[Simpo Two]

Gandahar said:

This is armchair science for laymen at it's finest. See, puzzle, think.

It does not even matter if we are all wrong. Newton would be proud !

Spot on! I like to figure out stuff.

This was no standing wave caused by nodes etc. The dust was only only on the pencil line.

I conclude it has to be static and the effect the graphite had on the field, either increasing it to attract, or decreasing it if the rest of the sheet was repelling.