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Re: heat packs in fall shipments?
Doug Karpa-Wilson wrote:
> I'm trying to arrange a shipment with someone who knows only slightly more
> about shipping than I. She was thinking of using some heat packs. Any
> suggestions on how to do this? We were thinking that having them somewhat
> insulated from the fish bag would be good to keep the fish from cooking.
Outside the styro. [It is almost as good as not using them, which I feel is
safest in most situations.]
Better, make the fish and water less sensitive to outside influences, by
*always* using a cardboard outer box. About 2" of extra newspaper, flat and
not crumpled, in the bottom of the styro box is excellent insurance against
cold aircraft floors. Bag the fish, as usual, with 3-4 times as much air as
water, but add other bags filled 100% with water for extra thermal mass.
Be sure all are inside a garbage bag, so the paper doesn't wick a leaking
bag dry. A bag, sitting in a puddle, will then never empty completely. Don't
tie too full as the 4000' altitude or so of a pressurized plane can burst
them. Just full enough to remove most wrinkles is ideal.
Once you are worried about the weather, it is time to a) increase insulation
and b) switch to Express Mail from a central post office. An International
Airport PO is the best. They often can tell you when the box will go out, so
you can use "just-in-time" delivery.
Get medical shippers from the local hospital's oncology dept. or hematology
lab. They are much thicker than fish styros (often 2-3" walls!), always come
in a cardboard fitted box, and are better for smaller shipments anyway.
Usually the labs have to add them to a land fill, so are delighted to have
you recycle them. The price is right (if you have ever had to purchase one)
I know that some regard my disdain for heat packs as heresy of the worst
kind. It is my judgement that even the newer long-life heat packs are too
uncontrolled to be safe. Also remember, they get their heat by removing
oxygen from the box. A regular 2.5 mil fish bag breathes quite a bit. Low
oxygen on the outside means it will lose oxygen and not replace any used up
by the fish. I don't see that as a very good idea. A set of heat packs,
outside the styro lid, and inside the cardboard box, is probably the safest
if you feel you really must use them.
Always figure that the maximum heat will be produced while the box is
sitting in a windowed mail truck in the sun on an unusually hot day. A
little extra insulation and some added thermal mass are more likely to
relieve thermal stress on most trips.
Free advice, of course, is worth every penny. ;-)
"The state represents violence in a
concentrated and organized form."
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