Sounds like you are doing sand casting of grey iron. If you are getting too much adhesion, I would look at the sand mix that you are using and the collapsibility rating, Are you using green sand with clay and water mix, or is it a resin based binder for the sand? There are additives that you can use in the sand to help or a plastic spray on release coating on the mold. There is usually a small amount of adhesion of material which is removed by shot blasting during the fettling process.

A good reference book to get you started is: Rao, T. V. (2003), Metal Casting: Principles and Practice, New Age International, ISBN 978-81-224-0843-0.

Ian Care

Thanks for your answer

We use resin as a binder in castings.

I will read the book you recommended

Can dust the surface with talc or fine clay to reduce adhesion. Don’t add too much as you want space to off gas to prevent porosity in the casting

Thanks for your advice

we use the carbophen as a binder, in handmade casting we haven't problem but in automatic casting, the sands don't shape completely and the corner of mold was empty. the sands flowability reduced with binder.

I thought maybe there was an additive that would fix this problem