Question

Increase in content of the binders in the core sand always increases the porosity of the core material.

(a) True

(b) False

I had been asked this question by my school principal while I was bunking the class.

The above asked question is from Forces Acting on Cores and Mold topic in section Mold and Mold Making of Casting-Forming-Welding I

Answer 1

Correct answer is (b) False

The best explanation: Increase in content of the binders in the core sand basically holds the sand grains together tightly and reduces the pore size in the core sand. So generally, there is a tendency for a reduction in the porosity of the core material. And the hardness of core sand increases continuously with the increase in the concentration of the binders.