If it happens, the bubbling was likely too much oil. It could be fixed by putting new layer of enamel over it, but I would suggest using base for gold or non ping since enamel does have a tenancy to pop off.
Mix whatever you decide to use with as little oil as possible.
Just enough so that it barely holds together (kinda like making a pie crust dough) . Then knead it together until its like putty. Then slowly add a touch of brush cleaner to it until it is thin enough to work with . You should be able to thin it down 3 to 5 times before you need to add more paste. Keep the mixed paste in a small jar and just pull out a little bit at a time when needed
Just enough so that it barely holds together (kinda like making a pie crust dough) . Then knead it together until its like putty. Then slowly add a touch of brush cleaner to it until it is thin enough to work with . You should be able to thin it down 3 to 5 times before you need to add more paste. Keep the mixed paste in a small jar and just pull out a little bit at a time when needed