Can superglue (cyanoacrylite) be thinned with acetone and still harden?
As you can see from the reaction of cyanoacrylate from Wikipedia, the carbonyl ($\ce{C=O}$) groups do not react with the cyano acrylate which means that acetone should not react with your super glue.



That does not mean though that any water present in the acetone won't. So you should make sure your acetone is dry. But even if the super glue does cure, it is dissolved in acetone and will still act as a binder for the Iron oxide.