Don't want to rain on your parade here....and it's probably something that has been discussed before in detail.....but I never ever repair tyres, having been given that advice from several sources.....none were tyre dealers or people who would gain from said advice.....but all were adamant (I was doing 400 motorway miles per week at the time) that replacement was the only safe option..and yes I was paying for the tyres....Conti's as it happens!