Protek Turns Green

[Tim Keenan & Rebecca Counts]

Also sprach Don Mannino:
> 

> I am going to put some Protec in a small plastic bottle with some center
> pins today, date the bottle, and put it on the shelf. Maybe in a year or
> so it will tell me something.
> 

Don and List:

If the experiment is to tell you if Protek oxidizes copper/brass, you 
need to do a controlled experiment. It would be even better to put some 
finely divided, freshly cut metal into the Protek-- perhaps take a piece 
of brass stock, start drilling a hole in it (with an absolutely clean 
bit), throw away the first curl or two off the bit, and then take the 
rest of the absolutely clean uncontaminated metal shavings that come out 
of the hole, and put them in the Protek.  Then take the piece of stock 
which has been exposed to the atmosphere for a while and put it in 
another jar of Protek.  You also need another jar of the same composition 
as the first two with nothing in it but Protek.

I think it at least as likely that what caused the green colour in the 
Protek is that a copper salt (copper sulphate, chromate, acetate, 
chlorate, chloride, all of which are green and all of which naturally 
form on surfaces containing copper and exposed to air or human sweat) 
which was present on the brass nozzle was soluble in the carrier solvent 
in the Protek. Colour which is not visible on the metal surface would be 
easily visible in solution.

Your formal "null hypothesis" would be that the metal has no effect on 
the colour of the Protek. If either of the vials containing the metal 
showed a colour change, you would reject the null hypothesis and conclude 
that there is an effect.  If both changed colour, you can conclude that 
the colour change is due to an effect of Protek upon brass.  If only the 
sample containing the dirty metal changes colour, you can conclude that 
Protek is good for cleaning brass.  Of course, in order to demonstrate 
that the result is not an accident, the experiment should be 
replicated--5 vials for each treatment would be adequate for some basic 
statistics.

Tim Keenan
Terrace BC