Re: A bit off topic - lost foam sand casting

From: Ron Ohler (
Date: Thu Aug 22 2002 - 14:48:49 EEST

A bit off topic - lost foam sand castingYes it is investment casting. A chemically bonded sand is used. This way the sand can be placed around the part and gently compacted by hand to control distortion of the pattern. We typically used an expanded polystyrene bead board (cheap insulation). There are special foam boards available. They have some improved qualities but are not a requirement for many types of castings. The pattern can easily be built from pieces and glued with small amounts white glue or epoxie. On a fireplace grate we had problems with the glue bond not being strong enough due to the length of the ribs compared to the bonding area. It was for personal use so we also used long nails to pin it together. They also helped stiffened the foam. Yes, they are still there-buried in the iron.
Ron Ohler/Ohler Machine ----- Original Message -----
  From: Ben May
  To: ''
  Sent: Thursday, August 22, 2002 6:10 AM
  Subject: A bit off topic - lost foam sand casting

  Greetings RP'ers

  Anyone out there know anything about lost foam sand casting. Most people I've spoken too seem to assume that it's an investment casting process wheras I'm sure I've heard of it being used for sand-casting. I need to know 2 things:-

  What grade of expanded polystyrene is typically used for the sacrificial patterns?
  Is there a foundry (preferably in the UK) that has experience of producing large bronze components using this process?

  Thanks in advance for your help

  Ben May
  Senior Development Manager

  Pankhurst Design and Developments Ltd
  85-87 Richford St
  London W6 7HJ
  Tel: 020 8735 1111
  Fax: 020 8735 1122

  This e-mail is private and confidential and is intended solely for the person it is addressed to. Any disclosure, distribution, copying or printing, or use of the information contained herein for whatever purpose by anyone other than the recipient is prohibited and legal action may be taken as a result.

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.4 : Tue Jan 21 2003 - 20:14:10 EET