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Trial Number 5

Trial Purpose:

To identify products that will brighten the brass parts after removing the paint.

Date Run:


Experiment Procedure:

Six products were selected based on vendor supplied information for removal of oxides and rust.  One solution was used at 2% and a second was used at 100%.  The other four were diluted to 30%.  Each solution was diluted with DI water in 140 ml beakers and heated to 150 F on a hot plate.  One brass part, free of paint, was immersed into each cleaner.  Observations were made at 5, 10 , 15 and 30 minutes.  At the end of the 30 minutes, the parts were wiped dry with a paper towel.

Trial Results:

All six products changed the appearance of the tarnished parts.  The Bio Z product brought the color of the brass closest to the desired end point, followed by Mirachem 250, Geo Guard 3015, Alukleen 36, Citranox, and the Glass Cleaner.  Table 1 lists the observations made at each of the four time intervals.

Cleaner 5 minutes 10 minutes 15 minutes 30 minutes
Citranox Pale copper color Green film Copper color w/ spots of brass color Flat brass color with green spots
Glass Cleaner Little improvement Turning dark green Mostly green with some brass spots Green coming off, more brass color
Geo Guard 3015 Quick copper color Red color Red with brass color Light brass with red tint
Alukleen 36 Copper color Pale purple Pale purple with dark spots Dark purple, lots of black
Bio Z Bass & copper color More brass than copper Brass color with spots Shiny spots, reddish brass color
Mirachem 250 Pale copper color Pale purple with brass color More brass color than purple Flat brass color with red spots

Success Rating:

Results successful using TACT (time, agitation, concentration, and temperature, as well as rinsing and drying) and/or other cleaning chemistries examined.


The top four products will be used in follow evaluation at lower concentrations to determine if a better brightening can be achieved at lower concentrations.

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