From: "Greg Crawford" <gc
To: <bruce
Date: Thu, 16 Mar 2006 10:45:52 +1100
Date: Thu, 16 Mar 2006 10:45:52 +1100
Cc: 

Bruce,

I apologise if I have missed replying to you. I have been receiving a confusing
where.

My blue filter has, on one side only, some kind of surface "frosting" almost all
the way to the middle. Hydrogen peroxide (which I tried following Arne's
suggestion), will not shift it. I suspect it may be some kind of microbiological
growth. I live in a hot, humid climate where night humidity is typically in the
day.

My V filter has misting in parts. It is very slight, and maybe I could get by.
expansion has resulted in the filter being too tightly encased and this has
broken a seal on the edges. Or maybe the effect is also caused by the entry of
worse.

I am not sure how much the edge cracking I can ignore, but the R filter's damage
extends in about 8 mm from the edge at one point.

If all filters will suffer from this, and have to be continually replaced, it
seems better to buy the cheapest. If a particular filter is immune, then maybe
increased cost is worth it ... up to a point.

- Greg

Sent: Thursday, 16 March 2006 10:25 AM

Greg,
   
  Getting back to your original email on the subject, you mentioned that your
current filters had deteriorated, and that they were made by Custom Scientific.
Since I don't believe that Custom Scientific uses BG39 glass to make their
filters, what kind of deterioration were you talking about?
   
  Bruce

Greg Crawford <gc
  >The solution for myself and a few others on this side of the Atlantic has 
>No sign of deterioration as yet after a couple of years.

Richard, can you please advise through whom you get filters treated like this?

- Greg


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