I recently received a "like-new" 300mm lens for my Pentax 67. Well, "like-new" except for that the built in lens hood is so loose that it extends when I point the lens down and retracts when I point the lens up. So I figured out how to remove the hood (the front half of the lens unscrews from the back half of the lens, then the hood slides off.) There are no threads or bayonet to hold the hood in place. All there is is a strip of material maybe a velvet of some kind (not familiar with fabrics, so I could be completely wrong). My assumption is that this material has crushed over the last 40 years and its no longer thick enough to hold the hood in place.
The seems like a fairly easy fix but what kind of material should I try? I know you can't tell me what thickness since that will be unique to this model lens, but if I go to the local hardware store and buy a strip of felt with an adhesive back, is that a good material? Are there better things to use? I mostly want it to work, but I'd also prefer it not scratch up the barrel while sliding forward and back, or hold dust and dirt and cause issues in the future.
The seems like a fairly easy fix but what kind of material should I try? I know you can't tell me what thickness since that will be unique to this model lens, but if I go to the local hardware store and buy a strip of felt with an adhesive back, is that a good material? Are there better things to use? I mostly want it to work, but I'd also prefer it not scratch up the barrel while sliding forward and back, or hold dust and dirt and cause issues in the future.