製作結合在一起的薄脆砂設計


16

我正在嘗試用沙子製作假幣,以便它們足夠堅固,可以握住它的邊緣,並且不會彎曲,但會變脆,因此如果我將其壓碎,它會崩潰回到沙子。

目前,我正試圖通過混合各種稠度的PVA膠和沙子來做到這一點,並且距離越來越近,但它不像我想要的那麼脆或牢固。

理想情況下,我希望它與餅乾或ryvita具有相似的一致性-我將在該項目中使用它,除了將其壓碎後,它應盡可能靠近沙子。

任何建議將不勝感激,謝謝:)


一些額外的細節:

我使用的是在eBay上購買的用於手工藝品的沙子,所以沙子非常好。至於比率/稠度,我曾嘗試使用PVA膠和橡膠水泥(分別),與沙子的比率為2:1、1、1:1和1:2(大致)。PVA太少,沙子不粘,太多,變得有點"鬆軟"。我不知道是否應該嘗試使用其他類型的膠水,或者混合使用其他膠水。我也嘗試過用動砂,但不會像普通砂那樣斷裂。

我最近的嘗試是用很多PVA膠水打磨,但效果卻有些鬆軟-但是我隨後在金屬噴漆上塗了一層塗料,看來可以牢固地粘合在一起。我還沒有嘗試將其壓碎,看看是否有可能,但是單獨使用噴漆可以解決問題嗎?

13

Fascinating project. The solution was right in your question; make it like a cracker — flour.

You're essentially making a sturdy paste instead of a glue. I mixed:

  • 3 parts sand
  • 1 part all-purpose or bread flour
  • Water, just enough to wet the sand

I drained off any excess water, packed it into a mold and let it dry in the sun (1-2 hours?). I guessed at the proportions empirically, but it worked great!


The disc to the right is a failed experiment with cornstarch

The coin was pretty solid… yet breakable. I could carry it around and drop it from a few feet without breaking it, yet I could snap the disc with a bit of deliberate force, and crush it down into sand by pounding it or working it between my fingers.

…after it is crushed it should appear as close to sand as possible.

Bonus that you're not adding anything permanent or inorganic to the sand. I could not see any flour when I crushed the coins back into sand, and dropping it into a cup of water broke it down completely (which makes it easy to pour off the flour-silt, if that's important to you).