Solvents for epoxy

The following appeared in sci.chem and is reposted here in slightly
altered form without the knowledge or consent of the authors.


  Article 6393 of sci.chem:
  From: srgxbhh [at] grace__dsir__govt__nz
  Subject: Dissolving Epoxy
  Date: 4 Apr 92

  In article <53514 [at] hydra__gatech__EDU>, gt3944c [at] prism__gatech__EDU
    (SHORROSH, RAED) writes:
  > In article <1992Apr2.145935.13443 [at] nntp__hut__fi> sakari [at] niksula__hut__fi
     (Sakari Aaltonen) writes:

  >>I have a small collection of dynamic RAMs, that is, memory chips,
  >>that could perhaps be used as optical detectors - they are
  >>out-of-date for computer purposes.
  >>The problem is that the chips are packaged in plastic which would
  >>have to be removed in order to expose the chips themselves to light.
  >>Does anyone know of a chemical substance that would dissolve the
  >>plastic? Mechanical methods do not seem to work.
  >
  >    Try Acetone.  It is a good solvent for some polymers.

  The only easy to use solvent we have found for Araldite ( an epoxy
  resin ) is Dimethylformamide - soak overnight at ambient temperature
  and then see if the epoxy has become slightly soft, if so keep soaking
  until it eventually swells and breaks away. Epoxy is not affected by
  most common solvents - such as acetone, methanol, chlorinated
  hydrocarbons, and hydrocarbons - at ambient temperatures, and I doubt
  electronic components would like the elevated temperatures where they
  do affect epoxy.

  Note that the DMF works by swelling and softening the epoxy, which
  slowly loses its strength and flakes off. I have encountered some
  epoxies that seemed to be more resistant, but after a couple of weeks
  they were soft enough for careful scraping to remove the material.

  *** SAFETY  WARNING ***

  Any chemical that munches into epoxy also does damage to humans under
  the same conditions, so please read the Material Safety Data Sheet
  that comes with the solvent. I use a fume cupboard and gloves when
  washing the the DMF from components with ordinary tap water. A garden
  hose outside would be a suitable alternative. The solvent can be
  reused if carefully decanted from the epoxy flakes.

  Bruce Hamilton                 SRGXBHH [at] grv__dsir__govt__nz


  Article 6394 of sci.chem:
  From: wilcox [at] tortoise__cis__ohio-state__edu (Patricia P Wilcox)
  Subject: Dissolving Epoxy
  Date: 5 Apr 92
  ...

  Further safety warning:  DMF is really dangerous.  The material safety
  data sheet may not adequately convey the extent of the risk of using
  this stuff.  See NIOSH alert DHHS (NIOSH) 90-105 (1990) for the
  details.

  --Pat Wilcox   (wilcox [at] cis__ohio-state__edu)
  --
  =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  "Anyone who thinks there can be such things as safe effective drugs
  is either ignorant or stupid."     ...Herman Rubin, sci.med, 3/5/92

                                  ***
                  Conservation DistList Instance 5:49
                 Distributed: Wednesday, April 15, 1992
                        Message Id: cdl-5-49-008
                                  ***