tyre pressures

[khm]

bit of advice please, did a track day this week, we run our tyres at 16 - 18 psi ( this is what we were told ) & on long stints (30 mins +)we started to get small blisters on the tyre surface. is this normal, have we got the right pressures ?
i always thought you would increase pressure to decrease the temp, but i have been told it's the other way round ??

Help !!!!!!!!!!!!!

[RobC]

What tyres, compound and construction?. Secondly, not wanting to insult you, but are you sure they are blisters?

[khm]

not insulted at all, nope not sure if they are, but one area of the tyre had a line about 50mm wide of what i can only describe as 'blisters' which were about 5mm dia. i will check the tyre specks.

[khm]

fronts are
avon 190/570r15 11940

rear
avon 240/600r16 11950

thats all the numbers i think

[RobC]

Could you post up a picture somewhere?