Making good lime mortar for painting

[Blakes]

After uncovering the existing fireplace and knocking off the old lime render of my solid stone house. I've got it back to the stonework and want to paint it kind of how it is now. I'm having a new woodburner stove fitted a week on Thursday, it's a covector stove so the rear of the fireplace won't get 'as hot' as a standard stove.

Anyhow, what's the best method to seal/provide a key for a coat of paint? Not sure how diluted PVA will work inside a working fireplace. I have a fresh tub of SBR in my arsenal if that may work?

Any ideas?

 

[Blakes]

Excuse the soot.....that will be getting cleaned up.

And the original stonework has been hacked to bits. Gutted as I can see how it would have looked originally and it would have been great. I'll build it back up with an sbr slurry coat and sbr render.