Does anyone have a simple recipe for making a stage prop flame redardant?

Question

or an easily shop-bought spray? my local DIY doesn't seem to be helpful!

Answer 1

The simplest way is to paint with intumescent paint but you will need to determine required fire rating eg: 1/2 hr, 1 hr etc.

Answer 2

First place I'd check would be a theatrical supply house.

I have no idea where you are, I'm in the US, but after being involved in theater for more than 45 years; Any open flame or pyro technics have needed approval. Certainly if this is professional theater. In any case a local Fire Marshall should be asked. If IATSE is involved, they may have rep. with that knowledge. Also then in not knowing your rationale for the question, or the idea, certainly the WWW general search would reveal hundreds of links probably.
Also in not knowing what the prop is, anything you use on it might alter it's aesthetic or functionality.

Answer 3

soak it in water