Use replace in rule

I would like to define two rules: one for the material and thickness the second one for volume and mass

rule1={t->1/2,row->1000}; rule2={v->t^3,m->v*row}; 

now if I used the following:

rule2/.rule1={v->1/8,m->v*1000} 

how to replace v in rule2 to get the following:

{v->1/8,m->125}