Rubber Protection

We need more information. (I have no idea what you mean by "used for light blocking like on a camera lens".)

There are rubber rejuvenators, such as Fedron. Are they what you're thinking of?

As in shade device.

Never heard of Fedron. Googling ...

MSDS shows it is mostly a cleaner.

I do not need a cleaner.

I need to protect from UV and air impurities that will deteriorate the rubber.

Regardless of the what the MSDS shows, Fedron works as a rejuvenator. It can soften badly hardened rubber.

Do you know how to use a search engine?

The Smithsonian uses cold storage:

How to store rubber and plastic parts:

I would not be so sure about your analysis. I have some instruments with rubber feet that have turned into a sticky gooey yucky semi-liquid mess. The problem is that out of 4 feet, only one has deteriorated. It was something in the environment, why didn't it attack only one rubber foot? I've seen similar situations with rubber idlers on tape and VCR recorders. Some of these have never seen the light of day, much less a UV lamp. My success with coating the rubber with something that blocks UV has been dismal. I use clear acrylic (Krylon) for this purpose to prevent deterioration of vinyl tape on outdoor antenna installations. It works just fine for this purpose, but not for protecting rubber. My conclusion is that UV has nothing to do with the rubber deterioration.

Another example is an Alienware (now Dell) laptop with a spray painted rubberized cover. The entire rubberized area is becoming sticky and will soon turn to goo. This includes areas which are NOT exposed to UV. If it were chemicals delivered from the users hands, it would be localized to areas of contact. That's not the situation as the entire surface is turning to goo. However, it might be an aromatic delivery mechanism.

Also note that when rubber turns to sticky goo, it does so over the entire volume of the rubber part and not just on the surface. If it were a chemical or optical attack, it would start at the surface, and be largely unaffected towards the interior. This is not the case, which leads me to suspect that it is NOT caused by an external attack.

I don't know exactly what causes the problem. My best guess(tm) is that the problem is in the manufacture of the rubber parts and paints. There seems to be a time delay involved, where everything is fine until some reaction occurs, causing instant self-destruction. Near as I can tell, what happens is that the rubber breaks cross links and returns to the petroleum based primordial tar from which it was originally derived.

This article: suggests that plastic and rubber continuously deteriorates. The deterioration can be accelerated by multiple sources.

There's lots of fans of "303 aerospace protectant" or something like that. You can get it at boating places, maybe some better auto parts stores.

What's the group's experience with Armor All? Seems to help non-porous surfaces, but I'd like something that would help with the foam stuff that lines instrument cases.

That foam stuff isn't rubber, and it generally takes a long time (at least a decade) to deteriorate.

Being porous, the foam's surface area is huge. You'd have to soak the foam in the protectant! The protectant would wind up coating the equipment.

If there were some chemical that absorbed "bad chemicals" that promoted the deterioration, it could be put within the case, in a porous bag.

I have several Pelican cases for photo and electronic equipment. They're about 10 years old, and the foam shows no sign of deterioration. If it does start disintegrating, I'll be able to buy a replacement insert (probably).

Thought I'd wandered into the wrong NG when I saw the heading 'Rubber Protection' ...

The OP did not answer my question as to whether he knew how to use a search engine.

Googling "rubber protectant" brings up over one million responses. Here's one...

By the way, the thing that protects a lens is a called a lens hood or lens shade. Other than generic models, they are no longer made of rubber.

The fact is that very few 'rubber' items are actually made from the sap of the rubber tree (Hevea brasiliensis). Rather, you are probably dealing with synthetic rubber, i.e. a flexible plastic. Natural rubber itself deteriorates from exposure to UV and to air. Stabilizers are incorporated into both natural and synthetic rubbers to increase durability. Depending on the stabilizers used, 'rubber' items will either get brittle or gummy when they age.

Spraying with a silicone compound won't help. The best you can do is remanufacture the part from a silicone based material.

PlainBill

ch

So that is what the OP was talking about, I figured if it was a lens hood he would have know enough to call it that.

Don't be too sure. Yes rubber get attacked by smog or other air pollutants.

Yes rubber and plastic does deteriorate / break down over time based on the chemicals used in the formulation. Some plastics turn hard and brittle, some turn to goo. The steering wheel on my truck goos out now. The plastic connectors on the engine wiring harness are now brittle and break easily.

As far as one out of four feet, well that can be totally based on something else. If that bad foot is near a fan circulating air the its environment is totally different than the other three. Other possibilities abound. Is that foot near some other device that makes it slightly warmer than the others, etc etc. Envirnomental problems.

Just saying it is difficult to blame on only one thing.

Chemically there are two Armour All products. The cleaner is a solvent that will attack stuff and I would never use it. This based on car magazines of a decade or so ago. The stuff that goes on the tires seems less problematic and might be helpful. Best as I can remember.

Which Armor All product?

The foam is porous. Spray with Armor all and you'll end up with a soggy wet sponge.

You can inject air bubbles into almost anything and create a foam like material. Polyurethane, Polyethylene, Silicon, Styrene, Neoprene, etc are common materials. Offhand, I suspect that silicon or fluorosilicone foam or sponge are the most chemically resistant and oxidation tolerant. Something like this:

Why would I google when I have experts here to answer first. Then I google to see if you know what you are talking about. :oÞ

Suggesting to Google is a cop out. >:|

Nobody mentioned KY Not Kentucky.

Because it's respectful to do your homework first, and show that you're worthy of assistance from experts.

We are not your servants.

I NEVER ask for help until I've done research of my own.

PLONK