Metal scraping: How to read the spotting

Here's a simulation I wrote in Lua (with Codea; great app!) on my iPad.
It shows, how spotting works, explains how to read the blue and what actually is happening with the blue that makes it look the way it looks.

Category:

Science & Technology

Tags:

• metal
• scraping
• spotting
• dykem
• canode
• engineers
• blue
• codea
• Lua

[mykedindeal]

So the black spots I can say are made by intimately rubbing 2 plates because the medium was squashed out .

[MuellerNick]

@mykedindeal

Not absolutely exact. This are two things happening one after the other.

First, rubbing the master against the work helps getting off the blue on the high spots. After that, the master polishes the work and you get the mirror. This is happening fast, as you already do have a fine finish.Those black spots can only be observed during the finishing. And again, you don't necessarily see/get them.

Rubbing:

[MuellerNick]

@MuellerNick

Don't rub too long. Maybe 5 circles or figures of 8 are about right. The longer you rubb, the more pronounced the reading gets.

[bluecoast1]

Thank you -- amazingly clear.

[lexichronicle2]

Lol, thanks nick, fullscreen, pause and rew all in use!

This is like reading SDS-PAGE gels for genetic sequencing. :D

[rcwarship]

Thank you very much, wonderful work.

[scurfman76]

Great work, thanks for sharing it.

[mykedindeal]

Best example ever.I finaly got it.Thank you

[LaKapec]

Thanks! Your videos about scraping are very helpful!!! Look forward your next videos!!