How to preserve plaster of paris and avoid it breaking away?

I'm making the Good Samaritan gun from Hellboy per the instructions on Indy Mogul. One of the parts of the gun, the barrel, (erm....where the bullets go), is made from plaster of paris. From experience, I've learned that this can break on its own eventually. Is there any way to avoid it weakening or breaking? Perhaps covering it with something?

caitlinsdad8 years ago
You could varnish or paint it to help keep it from chipping but cast plaster in itself needs to be handled gently like a vase. Try to recast your part but take some fiberfill and chop that up into tiny strands about the size of your thumbnail. Actually any fine synthetic(nylon polyester) thread will do. Technically this is like adding rebar to your concrete. The fibers will take the stress and hold everything together. Add a good pinch of the fiber to your plaster and mix well. The casting may have a little more texture but paint should smooth it out. Using a resin coating may help but then again, fiberglass shells are made with an underlying glass fabric mesh for strength. You could buy a bottle of expensive "liquid electrical tape" and paint your casting. It gives a thick rubber coating but is pretty toxic stuff. I guess you want to preserve the detail so it would be hard to put a new layer of something on the original without losing the sharp edges.
1Scray8 years ago
You could buy a new house!
Wasagi8 years ago
DUCT TAPE!! I would think that if you mixed it or covered it in epoxy too....