All paints come with VOCs (volatile organic compounds), and acrylic paint is no different (although the amount is less than other paints). More on wiping varnish in this previous Answer with essentially a full description of the process from finishing guru Bob Flexner.

Worktop Varnish | Wood Varnish for Kitchen Worktops

Hi, we have a working coal fire set in a reproduction victorian cast iron, with tiles up the sides surrounded by a wooden mantel and it all sits on a big brown shiny tiled repro hearth. From what you have said the fire has not been installed correctly in the space it is in and is getting the surrounding walls and surfaces too hot, this is also the most likely cause of the yellow blistering of your first paint (not mould). But still, if you’re exposing the latex acrylic painting to 360-degree F heat continuously for a couple of hours, it’ll surely get damaged.We can advise on paints and coatings covered in this article, but not on the underlying sand and cement/continued renovation work.

Best Heat Resistant Sealing Finishes for Tiles and Coasters

The 1 x coat of Zinsser Bulls Eye 1-2-3 followed by 2 x coats of Zinsser Perma-White Interior we recommend in the article above would adhere well to the surfaces you have mentioned and will cope with temperatures up to 70-80°C. Developed using the latest ceramic nano-technology integrated with silicone alkyds, this is the new standard in engine coatings. Protect and preserve interior and exterior wood against rot, mould, algae, fungal growth, insect attack and more with these treatments and woodworm killers. I tried spraying Dupli Color gloss products, both the engine spray and the gloss Clear coat, directly on the tile once the image was glued. Its more technical name is uralkyd varnish, and this makes it a little clearer that it is merely alkyd varnish with some polyurethane added to improve scratch and heat resistance.

Muuri ensures a breathable surface that is heat resistant up to 300°C (in standard white) and 180°C (in its 8 tinted colours), protecting the walls surrounding your fireplace or stove with a striking finish.

Polyvine Heavy Duty Extreme Varnish | Quick-drying Varnish Polyvine Heavy Duty Extreme Varnish | Quick-drying Varnish

Wash the paving with a pressure washer with the pressure between 2500 - 3000 psi and a spray lance, turbo-jet nozzle or similar specialist rotary attachment designed for cleaning concrete. When using spray paint, it is important to use protective equipment to protect a user’s eyes and airways, as well as ensuring decent air ventilation and disposal of empty cans. The fire is heating up the painted surfaces and causing them to discolour (yellowing) and then getting so hot the paint is blistering.Is Resin the way to go if I am wanting to coat coasters that I have acrylic painted and then plan to sell? The easiest way is of course to apply a fire-resistant coating on any type of wood to increase its heat resistance.