There have been great advances in regards to "Repaired Chips". Although your intention is good in that you are concerned with the chip continuing to crack, repairing chips is frowned upon for many different reasons. The board has had many discussions around repaired chips and the majority (myself included) believe that no alterations should be made to the chips... regardless of their condition and the owners intentions. In short, banning repaired chips is good for the hobby

I'll get off the soap box now

Matt