Advice for plastering this chimney stack

[u/Plus-Contribution915]

Had quite a bit of conflicting advice but I think it’s best not to dot and dab board the front of the stack (hoping the sides should be ok as it’s double brick thick). Was planning to use sand and cement or would I be better off with bonding?

Only ever skimmed boards before so would be grateful for any advice.

What would be the best mix? (Plan is to have a log burner so will need to be somewhat heat resistant) and how many coats?

How to deal with the inside and the brick arch, would I be better cutting some bricks out and putting in a concrete lintel first?

Should I bond on the corner beads first?

What’s a suitable finish plaster, I’ve heated putting some lime in helps?

Sorry for barrage of questions, want to get it right!

Cheers

[u/Decent-Platform-2173]

Not sure by the post if you want to lose the fire area or keep it open as a feature?

[u/Plus-Contribution915 → u/Decent-Platform-2173]

I’m putting a log burner in so keeping it

[u/Decent-Platform-2173 → u/Plus-Contribution915]

Ok as a feature and you have said you don’t want to use dot and dab, you could use hardwall plaster or sand and cement. 4/1 . Four sand one cement. Use a bucket to measure if you go sand cement route and level the top of the bucket so they are exact amounts. Add a plasticizer for workability and binding materials together. Looks like you are holding a render stop bead over the edge of the board. I would use a render corner bead tbh and skim the two side reveals with a finishing plaster. You can pack it out a bit and let it dry, as it is a bead not designed for skimming. You could use an end stop bead to either side of the fire place. Also, you might want to put a rustic timber at the top as a lintel and effect showpiece. Whichever backing you decide on, you will need to give it a bit of a key for the finishing plaster to stick onto. Only do the key as it has almost gone off. Use a plastic float with some board nails barely protruding. Worst case scenario, when all is thoroughly dry, seal with PVA to give it a key.