When I overhaul a set of timps, there is a lot of work involved over a period of days or even weeks. My approach is to fix everything properly; I am after all a professional and that is what I am being paid to do. However not everyone is as conscientious, and in the end, you get what you pay for. So when I work on timpani, I am fixing problems associated with wear and tear, and the dogs dinner that the previous person made of the job. The posts on timpani pick out examples of problems I encounter, rather than me writing, and you reading the same thing every time I do a set of timpani (which is why I have coloured this bit blue).

This set is a bit of a mixed bag of types of timpani, but the fibreglass bowls need repairing which gave me the opportunity to try and explain what is going on a bit better.

The knife is pointing at a little bubble in the rim of the timp bowl.

The other bowl in the pair also has problems on the bearing edge.

After everything is clean and dry, they can be filled.

It can now be seen that the previous repair on the second bowl was also not right, it was a low spot on the bearing edge.  The filler I used is still visible sat on top of the old grey filler, which means that the grey filler was below the line of the rim.