[RASMB] problems with housings

[Tom Laue]

Hi-
I agree with John  about the centerpieces. We have  sanded down the 
sides on many centerpieces. Another problem solvent with respect to 
swelling is high concentrations of DMSO and we have seen problems with 
centerpiece weakening in 6 M GuHCl. This leads to distortion and leaking 
at high speeds in subsequent runs.
I would suggest using a different glue since superglues are volatile and 
will evaporate in the vacuum (at least the ones I am familiar with). A 
tiny amount of epoxy will do the trick- the keyway ordinarily is held in 
by the fit.
Best wishes,
Tom
John Philo wrote:

>----------------------------------------------------------------------------------
>The older archived RASMB emails can be found at:
>http://rasmb-email.bbri.org/rasmb_archives
>and current archives at
>http://rasmb-email.bbri.org/pipermail/rasmb/
>Search All the Archives at:
>http://rasmb-email.bbri.org/rasmb_search.html
>----------------------------------------------------------------------------------
>
>Robert,
>
>Based on my experience, the problem is with your centerpieces, not your
>housings (although obviously you do need to fix the keys). I have similar
>issues with my charcoal epon centerpieces fairly regularly. Some of this is
>due, I think, to distortion over time from the centrifugal forces, but
>certain solvents also seem to cause the epoxy to swell (bleach is one
>example).
>
>What I do is to manually grind down the outside of the centerpiece (the
>sides, not the flat sealing faces) to reduce the diameter a little bit using
>wet/dry carborundum paper. I think I use 220 grit. 
>
>Regarding re-attaching the guide key, I use a little bit of superglue.
>
>John Philo
>Alliance Protein Laboratories
>
>-----Original Message-----
>From: rasmb-admin at rasmb-email.bbri.org
>[mailto:rasmb-admin at rasmb-email.bbri.org] On Behalf Of Robert Fairman
>Sent: Tuesday, August 12, 2003 8:28 AM
>To: rasmb at rasmb-email.bbri.org
>Subject: [RASMB] problems with housings
>
>
>----------------------------------------------------------------------------
>------
>The older archived RASMB emails can be found at:
>http://rasmb-email.bbri.org/rasmb_archives
>and current archives at http://rasmb-email.bbri.org/pipermail/rasmb/
>Search All the Archives at: http://rasmb-email.bbri.org/rasmb_search.html
>----------------------------------------------------------------------------
>------
>
>Hi All,
>
>Recently, I have had problems with tight-fitting six-channel 
>centerpieces in my housings.  It has resulted in the guide key 
>becoming detached from the housing.
>This has resulted in forcing me to retire three housings!  Has anyone 
>successfully re-attached the guide key to the housing?  And if so, 
>how would you recommend doing this?  Is it a matter of spot-welding 
>it back in place?
>
>Then, the next problem is dealing with how to avoid this in the 
>future.  Does the problem lie in the housings or the centerpieces?  I 
>guess it's not clear whether I should be spending my money on 
>replacing centerpieces or housings.
>
>Thanks for any help!
>
>Rob
>  
>

-- 
Department of Biochemistry and Molecular Biology
University of New Hampshire
Durham, NH 03824-3544
Phone: 603-862-2459
FAX:   603-862-0031
E-mail: Tom.Laue at unh.edu
www.bitc.unh.edu
www.camis.unh.edu