I just purchased a knife that came complete with a Kydex sheath and the usual warning about not storing the knife in the sheath.<br><br> I understand why I shouldn't store a knife in a leather sheath, and follow it religiously with my Randall collection, but is this warning still valid with Kydex, or is it just a hold-over from the leather sheaths.<br><br> Thanks<br><br> Seth

Hi Schaz,<br><br>The only thing I can imagine is that the Kydex/Concealex sheath may be humid/wet on the inside and when you store the knife in it for a prolonged period the humidity could condensate on the steel and because of the sometimes "tight" fit between the Kydex/Concealex sheath and the knife stay there a long time "trapped" and start doing it's corrosive work.<br><br>As far as I know Kydex/Concealex doesn't bleed any corrosive elements when it stays in contact with your knife in humid/cold conditions like a leather sheath will do.<br>I know because I just had one of my guns develop a nasty 3/16" corrosion spot from aggressive "juices" from a bianchi holster just near the muzzle where the leather tightly fitted around the slide it ate right through the perfect rust blued finish into the steel .<br><br>So tight fit and humidity on that tight fit spot could cause normal corrosion (the humidity can't easily get away) without the added corrosive properties of leather "juices".<br><br>Best Scouting wishes from Holland,<br><br>Bagheera

One of my knives, stored in a Kydex sheath that did not have a warning about storage, did in fact develop mild rust, even though stored in a reasonably dry drawer. On the other hand, I have a Buck that has spent the better part of two decades in a leather sheath with no rust at all.

I have a CS Recon Scout that has lived in a Kydex sheath for over ten years without a problem, but then I leave my Randall No 8 in its leather sheath most of the time too, and it has never had a problem either. But I use the Randall a lot, removing it from the sheath daily. I think the main problem would be moisture on the blade or in the sheath (the Kydex one)...might be a good idea to borrow the wifes hair dryer and blow out the sheath before storage.