Hey, .. Interesting thread..
I haven't had a chance to try this idea --> yet, ... can probably start tomorrow: Advance Autoparts (and etc) carries o-rings in 5-packs for like $5 or even $3, and you might even find them in singles for .40 cents. I doubt if there's any functional difference between these and what those other guys are selling for 10x more.
Here are the allknight sizes in relaxed and regular-fit:
Max Stretch 3.00 (Starting shape .75) Relaxed
Max Stretch 2.50 (Starting shape .50) Relaxed
Max Stretch 2.25 (Starting shape .75) Regular
Max Stretch 2.00 (Starting shape .75) Regular
.75 inch is (obviously) 3/4 inch. ---- and .50 is 1/2
Autoparts stores have stuff like that from sizes that'd fit inside your nose to sizes that'd fit around your skull..
Allknight's relaxed fit sizes are probably a '50' or '60' durometer' material .. and the regular fit are probably a 60 or 70. Lower is softer/stretchier, higher is harder/less stretchy.
Usually...
Silicone o-rings are different .. they tend to be both stiff and stretchy.
The website for that particular autostore doesn't list the material, or durometer, of their o-rings .. but it's probably a Buta-Nitrile .. which should be a 50 or a 60.
Whatever the material, the stretchier the better ,, because they'll still exert most of the force of a stiffer material but should last a lot longer without breaking from being taken off and on, and per-each will be less abusive to your tissues.
I'm trying the autopart product first because (assuming availability of the right ones in stock) they should be right around the corner from me on my way to everywhere..
You can also find packs of o-rings on Amazon for cheap..
And absolutely you can find them at McMaster-Carr ..
http://www.mcmaster.com/#o-rings/=qat23t
.. in every possible material .. in packs of 100 for like $3 to $10 ..
Neoprene, Silicone, Buta-N, and Polyurethane should all be usable..
There's as much as a 20% difference between the size as measured at the outside diameter (OD) and the inside diameter (ID). An o-ring that's .75 inch OD might only be .62 inch ID, this won't matter much because it's all stretchy, but keep that in mind if you think you might need to go up (or down) a size or two ... the selection at McMaster would let you.
One more thought, per some explanation at the Allknight site, it makes more sense to use more of the stretchier o-rings stacked together (like 5 to 10 of them) for what I'd call a
yielding occlusion, rather than using fewer stiffer ones (like three to five of them) for what I'd call a
harsh occlusion.
The stretchier ones will have less force (each), but they should last longer, and by using a few more of them stacked they'll add up to essentially the same constriction power but spread across more area so it's less destructive of your tissues, allowing you to wear them more often and for longer.
Will report on autoparts o-rings pretty soon unless someone wants to beat me to it
, and asap will also go ahead and order some others in several different materials from McMaster.
