Red/orange spots on cement frag plugs when using super glue

[Swip]

Hi everyone,

just a question out of curiosity.
If I superglue something to frag plugs that are made out of white portland cement the area where the glue was gets red/orange.
Does anybody know why that happens?

 

[kschweer]

I'm no chemist but I would have to guess its some kind of chemical reaction. Maybe @redfishbluefish can shed some light on this.

 

[Randy Holmes-Farley Verified Community Expert]

Hi everyone,

just a question out of curiosity.
If I superglue something to frag plugs that are made out of white portland cement the area where the glue was gets red/orange.
Does anybody know why that happens?

How fast of a change are you talking about?

My guess is you changed the oxidation state of a metal like iron in the near surface of the cement.

 

[Swip]

About a week maybe less. But only on spots where the superglue is. The rest of the plug remains white.

 

[redfishbluefish]

Here's my speculation. Portland contains chromium. There are chromium compounds (such as chromium acetate) that are red in color. I think you've formed a chromium acrylate that just so happens to be red/orange. Your a chemist and you don't even know it! Then again, Randy could be right with an oxidized iron compound. Pretty neat! It's like instantaneous artificial red/orange coraline.


EDIT TO ADD:

I just looked up White Portland (versus what I knew about the more common "gray" Portland), and found that the chromium has been removed, down to 0.003 percent, so my guess is most likely wrong. I'll go with Randy....an iron oxide of some kind.