How does Clarke bring out the significance of renewing the bond of friendship in "Still Life"? Support your answer with various poetic devices.

In this poem, Clarke uses the extended metaphor of polishing brass to depict the renewal of friendship. Literally, the two friends "polish brass" together, but the act is symbolically representative of far more than that. In performing this act, the friends' hands become "slightly gritty . . . as they would feel / If we'd been in the sea, salty." This simile suggests an allusion to other things the friends might once have done together; the act of polishing the brass not only recalls other good memories but leaves a literal residue on the skin. In performing this act together, a physical reminder is enacted on the body.
The extended metaphor of the brass polishing is used to convey how spending time together in pursuit of an active goal seems to have a similar effect on the friendship itself. In polishing, it is "as if we burnished our friendship . . . until all the light-drowning tarnish of deceit were stroked away." Language like "burnished" and "tarnish" draws the reader's attention because of the assonance in the words but also because of the semantic field they create of light and the absence of light, along with "light-drowning." Deceit has "tarnished" their friendship just as tarnish has darkened the glow of brass, but in the act of rubbing, that tarnish can be rubbed away—it is not permanent.
Even as the tarnish disappears, "patterns of incredible honesty delicately grew." With the removal of the layers of deceit, then, the friends are able to uncover what lies beneath, and this is not difficult—the patterns are revealed "quite openly" under the right attention. The yellow, glowing motif continues to represent the truth of friendship, as the friends create "a yellow-gold still life" out of the pieces they polish, a bright image of their friendship forged by their actions. The heat of each object, Clarke says, is "illusory"—"essentially each object remains cold, separate, only reflecting the other's warmth." Heat and warmth is imparted into a friendship, then, only because the friends reflect each other's warmth and attention. If attention is paid to a friendship, it can easily be rejuvenated, its "tarnish" buffed away, but if it is not cared for, friendship does not have the warmth to sustain itself.