Rendering for the inside of a fireplace

[Tim S]

One more (ta in advance and all that)

I have to render the inside of a fireplace, in order that a wood/coal burning iron stove can go in later.

What would be the recommended mix for that? Something with lime maybe?

On an aside - I'd like to "paint" it white. Paint's not going to like the heat - so I thought of whitewash/distemper - basically something white, paintable and lime based. Is that something I could make starting with a bag of lime? Google's not being helpful with regard to just buying "whitewash" and "distemper" is more of a doggie disease(!)

Nearest I could find was this:

whitewash, limewash and distemper all the same thing?

Ta

Tim

[RubberBiker]

Whitewash/limewash same thing. Distemper includes linseed oil I think.

You can make whitewash from a bag of builders lime (=A35/bag and one bag will last the rest of your life) - mix with water in a plastic dustbin and leave as long as possible (days/months/years) - this will give you lime putty at the bottom, with excess water on top. When needed, swirl it up and scoop off some of the whitewash. Coats should be painted on so thinly to be semi-transparent when wet. Build up lots of coats.

[Tim S]

RubberBiker wibbled:

Genius - thanks for that. Better start my bin of putty soon then.

Cheers

Tim

[Harry Stottle]

An old plasterer told once me the best way to neutralise soot, and get it to accept plaster, is to mix cow dung with water in a bucket and paint it on. Just searched to see if this was true, and found the following link:-

[The Natural Philosopher]

Do a smooth render with white cement and washed playpit/silver sand.

Don't bother painting,

[Tim S]

Harry Stottle coughed up some electrons that declared:

Fascinating! I'm almost tempted - plenty of cows round here, somewhere...

[Tim S]

The Natural Philosopher coughed up some electrons that declared:

That's an original idea. Could it still be worth shoving a bit of lime in as a plasticiser?

[The Natural Philosopher]

If you want. Not sure if we did. However it does get dirty fast ;-)

[David]

We were advised by the wizened and experienced stove man to go for a weak mix (5 parts sand to one cement). When this was dry, we painted it with normal paint.

Since then, we've had the stove on quite a bit (last night...in July...) and no problems.

David

[Andy Dingley]

link:-

'd ask Anna Kettle about this, but I'm fairly reliably informed that any old recipe for cow dung related plasterwork needs care if you use modern dairy output. It's the change in diet and hyper-breeding of cows that resemble industrial fermenters. If you're "shopping" for cowpats, take them from the fields where the bullocks are, not the milking parlour or the slurry lagoon. If you do use dairy output, check that the water content is still what the recipe expected.

Errors in this area may leave you with a bathtub full of extra-runny wattle & daub mix that refuses to stay daubed and gets stinkier by the day...

[Tim S]

The Natural Philosopher coughed up some electrons that declared:

>

Some timely feedback is due I think.

I followed your suggestion, using a 1:1:5 of snowcrete (white portland cement), lime and playsand.

I wirebrushed the crap off the fireplace (wasn't too sooty save for a few spots) and primed with a wet cement slurry.

I made the render fairy sloppy (the lime certainly helps hold it togther) then applied.

It worked pretty well. It dried to a very light beige and looks quite natural. Job done - thanks for the inspiration!

Cheers

Tim