Yes, I'm aware that the newer OXCOs don't have any insulation other than air
inside the package. I failed to mention that in my post. I am primarily
interested in the older OXCOs that have foam insulation inside. I have a
couple of them, including the crystal oven from an old HP 5245L counter that
needs new insulation. The old foam was destroyed by a heater that ran wide
open for a while, burning a large portion of it to a crispy mess.
Thanks for your response,
Dave M
Bob Camp wrote:
Hi
A lot of modern OCXO’s no longer use insulation…. the gaps inside are
now so
small that you get very little benefit from it.
On the older parts that do use insulation 2 to 4 pound per cubic foot
density
urethane foam is a typical choice. You can buy it from most plastics
suppliers. It
can be machined with just about any tooling out there. The dust is a
mess, but
it’s not normally considered hazardous.
Bob
On Feb 21, 2015, at 7:09 PM, Dave M <dgmin...@mediacombb.net> wrote:
What kind of foam insulation is generally used inside an OXCO? Do
all manufacturers use the same kind? Is it available in small
(hobbyist) amounts?
I've read that some folks have used Great Stuff polyurethane-based
insulating foam to repair an OXCO. I've used it to fill gaps around
pipes in my home, but it's nor subjected to the high heat
encountered in an OXCO. According to Dow's web site, it could
present a fire hazard if subjected to temperature of 240F (115C).
There is a "Fireblock" variety, but it appears to have pretty much
the same formulation as the other varieties, so I can't see any
advantage to it.
Has anyone experienced any long term problems with Great Stuff in an
OXCO?
Dave M
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
