Latex is a questionable material to use when there are much better
alternatives, from McMaster-Carr on latex:

Oil and flame resistance - poor
Weather and oxidation resistance - fair
Ozone resistance - poor

Like Eric, I've been using silicone tubing for the connection to instruments
for years. It retains its elasticity and is excellent in all three
categories; weather, oxidation, and ozone resistance.

Besides the options of using small hose cinch clamps or O-rings (silicon,
viton or EPDM resist weather well), MC also sells "Caps for Caulking
Tube/Glue Bottles. These are like miniature condoms and are designed to
unroll onto the tip of a bottle or applicator. They have great elasticity
(probably strong enough to cinch down even a relatively hard hose) and I
imagine would weather well also. To use them on a hose, one would cut off
the tip and roll them out on the hose, place hose over instrument nipple and
then roll cap back up onto nipple.

MC item number is 7526A11 $4.48 per package of 35 ea.

If you don't like 'em for hoses, you can always use them for sealing
caulking tubes (g).

bumper


"jcarlyle" wrote in message
oups.com...
I did some research on this subject. Turns out that the proprietary
term is "elastrator ring", used with a device called (naturally) an
"elastrator" for castrating calves, goats and lambs. Mostly they are
green in color, but they also come in blue and orange in quantities of
100, 500 and 2000. Apparently there are two materials that they are
made from, with latex "expanding 170% more and gripping tighter" than
whatever the normal material is. I found no information about size; but
since Mike Borgelt has found that they work in our exact application
the question is settled.

In the USA you can find them at at veterinary and farm supply firms,
see ( http://shop.store.yahoo.com/animalme...re/cassup.html ). One
potential problem is that they are so cheap ($1.20 for 100) you might
run into a minimum order size problem if you mail order them.

Warning - if you're squeamish, don't investigate this subject too
thoroughly! There are some graphic pictures of these things in use,
plus painful descriptions of animals reacting to them. There's also
some kinky stuff on human use out there, too. You've been warned!

-John


Martin Gregorie wrote:
jcarlyle wrote:
Sheep castraters, eh? That's well outside my life's experience! What
would be a source of supply for such a thing?

Try a Stock & Station Agent from an American sheep-farming area. Sorry,
but I don't know American for "Stock & Station Agent".

In NZ the rings are called "emasculator rings", but the name may be
different in the US, especially if the PC pests have been at work.


--
martin@ | Martin Gregorie
gregorie. |
org | Zappa fan & glider pilot