Quote Originally Posted by kilted hillbilly View Post
It makes me want to HARL! But seriously,if it has to be "re-harled" every so often, does that men the old harl sluffs off after a time? If so, wouldnt the paint come off with the harling? Problem solved.
Yup, that's exactly what happens. Due to expansion/contraction caused by heat/cold tiny cracks do appear in the harl. These cracks admit water, which builds up between the harl and the fabric of the castle. Eventually these pockets of water freeze, and chunks of harl pop off. While these holes can be patched, eventually the building has to be re-harled.

It's been years since I was last at Kelburn, so I haven't a clue as to the condition of the fabric of the building. That said I suspect that the murals would have a predictable life of between 5 and 10 years.