It is a little late for the first rubbing time, so the rubbing condition is not perfect.
It would be easier to rub it right after kneading it a little more.
On the other hand, it is a good time to give it shape.
I think the best time to give it shape is 15 to 40 minutes after mixing.
I am giving the time at random, so please do not blindly believe me.
Timing of rubbing the mixture as an adhesive (immediately after mixing)
When you can start to get a bit of a response and use your fingers or a spatula to get a shape (15 minutes after mixing – slower in winter).
When it becomes very hard and you can rub it with a delli spatula to smooth out bumps and waviness (before it is fully cured, the effect is such that it does not deform with your finger and leaves a fingernail mark).
It is necessary to learn such timing with your body when working with epoxy putty.
Ideally, as much modeling as possible should be done during the epoxy application.
It is a mistake to change the silhouette by paper hanging.