I use radiator paint from B&Q

Providing the block is perfectly clean it will not peal off at any temperature its safe to let your block get too.

Useful for if you build an engine and someone runs it without water and badly overheats it though, cause it comes off then!


Available in ANY colour, literally take something you want it matched to and they will mix it apparently, although i always just buy the "off the shelf" red one personally.


When you use it the colour changes a bit when it first gets hot so dont worry if it doesnt look exactly the same as its supposed to.