Black on black
QI have used Johnstone’s Black Bitumen paint on my 2004 narrowboat since new. I wonder whether it would be okay to use other manufactures’ black bitumen paint, eg Master Bitumens. I found this on eBay and it seems to do the same as Johnstone’s and costs the same for a five-litre tin. However, Master Bitumens also does a 25-litre version which brings the price down by more than 50%.
TONY BAKINOWSKI, via email
TONY REPLIES... The two products should be compatible, it’s just bitumen on bitumen. But it’s always a good idea to try a small area first and leave it for a while to see if any reaction occurs. It shouldn’t, but it’s best to be sure.