material for holding a lens hood in place by friction

[abruzzi]

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.

 

[paul ron]

you can get a velvet ribbon from craft stores like Michaels.

 

[shutterfinger]

Velvet, may be hard to find, yarn, felt (but I'm not a fan of the self adhesive type) are the common materials used in cameras.
Try a hobby shop such as Michaels http://www.michaels.com/

 

[abruzzi]

if you don't use self adhesive, what would you use as an adhesive, rubber cement? I definitely don't want to use super glue.

No Michaels around here, there is a Hobby Lobby and JoAnn fabric, though I've never been in either. I'll have to check it out this weekend.

thanks.

 

[shutterfinger]

if you don't use self adhesive, what would you use as an adhesive, rubber cement?

Rubber cement will come loose too easily as does self adhesive felt unless its stationary. Pliobond 25 works well.
https://www.ebay.com/itm/AUTOMOTIVE-MARINE-AIRCRAFT-HOME-APPROVED-Adhesive-Pliobond-25-LV-3oz-Bottle/292438243671?epid=2241193682&hash=item4416ad7957:g:kdkAAOSwJ7RYWCcw

 

[abruzzi]

cool. thanks for the recommendation. It looks like acetone breaks it down, which is good to know as well.

Now I need to figure out how to get the old stuff off without being too destructive. maybe try acetone on that as well.

 

[paul ron]

velvet ribbon is not rare at all...... Ive used it for light baffles on film holders and dark slide traps.

http://www.michaels.com/search?q=velvet ribbon

Thin double sided tape is the best, anything else will build too high and make the fit uneven or too tight.

 

[Poisson Du Jour]

All there is is a strip of material maybe a velvet of some kind (not familiar with fabrics, so I could be completely wrong).

It is flocking, applied electrostatically by the factory then heat bonded.
It can be purchased at craft stores and usually has a very light tacky self-adhesive base.
A lot of flocking deteriorated on Pentax 6x7 lenses (inside hoods, around the rear element flange etc.) after many years. Whether or not Pentax learned from that and improved the process I don't know.

 

[Sirius Glass]

You can order from Michaels at www.michaels.com. Some of the velvet strips may come with adhesive. Email Michaels, Joann, et al for suggestions about what adhesives are good to use.

 

[Born2Late]

What about the loop side of Velcro?

 

[shutterfinger]

When using Pliobond apply a thin layer of the cement to the surface to be bonded to, lay the velvet or felt onto the wet cement then repeat for the next section. No build up, thin layer.
Is there a convenient source for the thin double sided tape you mention Paul? I've had products that came with the double sided tape to come loose from the tape.

What about the loop side of Velcro?

To thick and coarse for the application.

 

[monst]

Self adhesive black flocking for putting on the inside of telescopes should do it.

 

[paul ron]

where do you get that flocking material?

the tape i use to get from 3m is the thin scotch tape type used to put moldings n tags on cars, an outdoor tape. i think you can get it from auto supply stores. another tape i happened to get was from a golf pro shop called grip tape.

i know plibond is a widely used adhesive, even recomended by camera manufactrers. but i found when cameras have to be opened regularly for maintenance, the leatherete put on with tape was easier to remove without destorting or destrying it.

 

[albada]

I am aware of two websites that sell flocking material for telescopes:
scopestuff.com , and protostar.biz
I suspect that both are one-man operations. I bought some material from scopestuff. It's fine.

Mark Overton

 

[EdSawyer]

flocking like is used in telescopes is not designed for rubbing or friction. It will result in flocking particles being dislodged from the material. I'd use felt or leather. Pliobond is good, or any contact cement really (I like the black 3M automotive trim adhesive)

-Ed

 

[StanMac]

cool. thanks for the recomendation . . .Now I need to figure out how to get the old stuff off without being too destructive. maybe try acetone on that as well.

YIKES!!!! Never ever use acetone on any part of a camera. Acetone is an extremely potent solvent that will dissolve just about any paint, finish, or plastic it comes into contact with!

Stan