James Rouse wrote:
>=20
> Do the smearing/fading problems discussed render the plates useless
> or can a very thorough cleaning restore their usefulness? This is
> a very useful technical discussion for our facility. Thanks to
> everyone who participates.
James,
First, you might want to send your note to the ABRF email list -=20
you sent it only to me. No problem if you want to keep it as a
private discussion.
The plates can be restored to use, yes. It requires a thorough
cleaning, and to date we have not found anything that *always*
works. The ones we see the best results from are:
- soak in 1M NH3 overnight
- soak in 5% MultiTerge overnight
There's some belief that a serious scrubbing with *hot* distilled
water and a sponge also does the trick (the standard synthetic
kitchen sponges are fine). There's some question in my mind about
the sponge job, though. It's used as a preventative as much as a
restorative measure, and the tech who uses this may be seeing less
severe smear effects than the others because she does it routinely.
I've heard of a few ammonia-based or quaternary amine-based
cleaning compounds that are reputed to fix bad plates. There are
commercial cleaning compounds sold - 'SequeSoap' and 'SequeScrub' -
that were only somewhat helpful. There are others as well that
I've yet to try.
Other things we've tried that had no effects include 1M HCl,
1M NaOH, hot water soaks *without* the scrubbing, and some commercial
lime removers (on the theory that it's a hard-water deposit).
In summary, avoid tap water, wash with *hot* distilled water and
lots of elbow grease, and if you start seeing problems, try an
ammonia soak (1M). FMC BurstPacks show less smearing/fading than
homemade acryl mixes. No matter what we do, though, we eventually
see more fades/smears and they continue to cost us money and time.
I sure would like to know a Final Solution to this.
PLEASE let me know your own experiences. Have you been having smears
or fades? I would at least like to add your site to my list of
'frustrated ABI customers' in case they need proof this is a problem
they need to address. Have you found anything that seems to improve
the symptoms?
Bob Lyons
University of Michigan