tolkiens legendarium - Why not encase the One Ring in solid metal?

In the Lord of the Rings, the One Ring corrupts the people near it, and it seems to have a stronger effect on anyone who sees it or touches it. Sauron and the Ring Wraiths also seem to be able to sense the One Ring when someone wears it.

Once the Council of Elrond decided to destroy it, why did they not take additional steps to help their people resist the temptation of the ring?

Put the ring into a small lockbox. Or, better yet, solidify molten metal around it. Do something so that the One Ring cannot be worn, seen, or touched without great difficulty. You can still cast the container into the Crack of Doom, and the ring would be destroyed along with it.

There are clear literary reasons for the lack of such preparations, but if there are in-story reasons not to take any such steps, I would like to know.

Answer

It would possibly have had a negative effect on the bearer if they could not see it.

I tried locking it up, but I found I couldn’t rest without it in my pocket. I don’t know why. And I don’t seem able to make up my mind.’ ^{A long expected party}

Here we see Bilbo getting anxious because the ring is locked (presumably in just a chest)

It also would not have altered the ring's malevolent hold over the bearer's mind, as Gandalf says to Denethor

Denethor; yet if you had received this thing, it would have overthrown you. Were it buried beneath the roots of Mindolluin, still it would burn your mind away, as the darkness grows, and the yet worse things follow that soon shall come upon us.’ ^{The Siege of Gondor}

In addition, (credit to user void_ptr) the bearer of the ring would have struggled to accept such an attack on the ring.

Frodo is unwilling to hand the ring on its chain to Gandalf and is distressed by it being heated in his fire.

‘Well then, look!’ To Frodo’s astonishment and distress the wizard threw it suddenly into the middle of a glowing corner of the fire. ^{Shadow of the Past}

This is a similar reaction to early words of Isildur.

and maybe were the gold made hot again, the writing would be refreshed. But for my part I will risk no hurt to this thing: of all the works of Sauron the only fair. It is precious to me, though I buy it with great pain. ^{The Council of Elrond}

In short, it wouldn't have done much good and would have risked destabilising the bearer even more so.