Question

In the Shell Core making, when the sand blowing is employed, it is preferred to use resin precoated sands to avoid resin segregation.

(a) True

(b) False

I got this question by my college professor while I was bunking the class.

My enquiry is from Methods of Making Cores topic in chapter Sand Moulding of Foundry and Forging

Answer 1

Correct answer is (a) True

The best explanation: In shell core making, the sand is mixed with about 2% to 5%  thermosetting resin of phenolic type is either dumped or blown and then when the sand blowing is carried out, resin precoated sand is preferred to impart high permeability and smooth surfaces.