Is it possible to dissolve plaster?

I have a brass lamp base that's mistakenly been filled with plaster during a restoring project. The problem is, plaster (or some element in it) corrodes copper and copped based alloys. There's quite a bit of it and removing it by carving little by little by hand is really not a possibility. Is there any way to dissolve it, or make it much softer or more brittle?

 

I can think of ways to crack plaster, but all of them would also do a number on the lamp.

 

You could try one of those vibrating engravers used to put you name on metal objects. They work well at digging out fossils from hard rock. As long as you stay away from the lamps metal you should be fine just be sure to avoid over heating as they burn out fairly easily.
Cheers
Stephen

 

Dremel?

 

Seems like there's not going to be a simple and easy way to remove it without a lot of work. I'll have to try different methods and see what works best. Thanks for the suggestions so far.

 

Vinegar dissolves plaster, but probably not suitable for this project. Drill holes like perforations around the edges & try to chip out from there? Maybe fill the holes with vinegar? Might make breaking out a lot easier. Might.

 

That's what I was thinking too. I'd wait for the weather to warm up, and then take it outside with the dremel and have at.

 

That's one reason I thought it might not be good for this application. But I could see making some bore holes away from the sides & not deep enough to touch other metal parts, & carefully adding vinegar, just to make the Dremeling easier. Only thought of it because my dad once told me a story of getting a plaster cast off a baby using a method something like this when others were afraid to use the cast cutter. Just a thought. The question was whether it is possible to dissolve plaster, not whether it is a good idea.

 

I had a weird moment and against better knowledge poured a bit of bleach on the plaster to see if it would loosen it up. Of course it went through a hole and came into contact with the brass. In panic I soaked the lamp in water to remove the bleach (chlorides!)

There are three screws / threaded rods going through the plaster, which means it's super lodged in. The lamp however is sturdy and heavy, so I'm tempted to drop it on the floor and see if the plaster would crack.