# Can superglue (cyanoacrylite) be thinned with acetone and still harden?

I'm looking for something with an extremely low viscosity to use as a binder for cold casting iron oxide with very fine detail (it's to make a slotted winding core for an electric motor with $$\pu{1mm}$$ slots). My plan is to thin out the superglue with acetone enough to make a slurry for pouring in the mold - possibly also mix in some water just before the pour to speed the setting process.

My question will superglue still harden if it has been thinned with acetone or would this destroy whatever properties that make superglue such a useful substance once it hardens? It's stated in many places on the internet that acetone works as a solvent for CA glue but this is only ever mentioned in the context of dissolving the end result.

• Superglue for modelers (hobby/craft stores) can be found in different viscosities. – Jon Custer Oct 3 '18 at 21:09
• The Iron oxide is extremely fine and requires a lot of mixing to get any liquid mixed through it - I would expect no matter what viscosity the glue came in it would start to set while I was still mixing it through. With a solvent I can wet it first and then mix the glue through with a longer working time (this is my theory - will put it to the test this morning). – norlesh Oct 4 '18 at 0:59
• The problem with using superglue for this is that it cures quickly and is likely triggered by the OH groups present in the surface of the iron particles. This makes it unlikely you will get good mixing. You probably need to find some alternative polymer where mixing can be done before adding a curing agent to trigger polymerisation. – matt_black Oct 5 '18 at 10:44

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.

• Not just dry, but very very very dry. I'd wonder if you'd get something like a sponge structure at best rather than a "complete" solid structure. I'd also suspect a much longer curing time if the water content of the acetone was low enough to not catalyze the reaction. – MaxW Oct 3 '18 at 21:37
• Thanks, sounds like it's at least worth an experiment then - will dry the acetone with epsom salt crystals first. – norlesh Oct 4 '18 at 0:50
• Your iron oxide contains a huge amount of water at the surface. There is no chance you will be able to properly mix this before it sets. Why don't you go for some epoxy resin? – Karl Oct 4 '18 at 7:33