What rot

Hi,

I have an SF7 which has been sitting on the shelf since I started digital photography, about eight years ago. I have been checking it periodically and did so last weekend, when I found that the rubber eyecup had started to decompose, leaching a sticky goo on which was growing a white mould. The mould had spread to the nearby plastic body. I removed the eyecup (it fell apart in my fingers!) and cleaned the camera with Dettox (no idea whether this actually kills mould), then left the camera and lens to air in room well away from the rest of my gear.

I usually keep silica gel packs with my gear, but for some stupid reason left the SF7 in the leather case (the kind that fits flush to the lower half of the body) and without silica. Very remiss. I suspect that the rubber started to decompose first (ever found an old rubber band in the bottom of a drawer), creating the conditions for the mould to grow, rather than the camera getting damp then the mould growing and 'attacking' the rubber. The room and all of my other gear is dry and clean.

Is there anything else I should do to clean the camera and lens? If no further mould appears in the next couple of weeks, can I assume it is safe to mix with the rest of my gear (I was thinking of putting the lens on my old *ist DS)?

I don't know what developments in rubber/plastics there have been in the twenty years since I bought the SF7, but I wonder, can we expect similar aging issues with the rubber parts on our DSLRs and weather resistant lenses? Will a service with full seal replacement by necessary periodically, say every ten years? What with new gear out every year, it's hard to picture such a lifespan for a DSLR, but I won't be buying every new model or even every other, and I certainly expect lenses to last decades. Does anyone here have experience of maintaining gear with rubber seals over this length of time?

Any advice and information appreciated,

Derek.

Kit is best kept dry and well aired which helps prevent the mould growing. The fungal spores are everywhere in the air, but they take hold when enclosed in warm damp conditions, especially within a leather case, drawer or cupboard.

Also drawers and cupboards are not good as the wood glues used can cause problems with the chemicals that they leak into the air.

Apart from the kit I keep in my Billingham bags, ready for use, everything else is on open shelving in a dry centrally heated room.

Possible addition to John's thoughts - avoid storing camera equipment in direct sunlight.

The eyecup will have been covered in sweat and oils from your skin which might have caused the rot.

I would suggest that you keep your kit in a good quality case such as a Billingham,(like John does), or a Lowepro,(like I do), or a Tamrac, and always, always, with a bag of silica gel in the bottom of the case!

Kind regards,

Peter.

[/quote]I would suggest that you keep your kit in a good quality case such as a Billingham,(like John does), or a Lowepro,(like I do), or a Tamrac, and always, always, with a bag of silica gel in the bottom of the case!

[/quote]What size/weight of silica gel sachet would be recommended?

JR only keeps his frequently used kit in a bag, ready for action at a moment's notice. The less-used stuff is kept in the open air.

Out of direct sunlight, no doubt.

G

I'm sure you are all trying to be helpful and probably after the first reply everyone just latched on and didn't read the original post, but I didn't ask the best way to keep gear. I already know it was stupid to leave the SF7 in the leather case and did state that the rest of the gear is dry, clean and kept with silica gel.

What I actually asked was:

Is there anything else I should do to clean the camera and lens?
Is it safe to mix with the rest of my gear?

to which the answers are probably no and yes, so long as I store the gear properly.


But I was actually hoping someone might be able to answer these questions:

Can we expect similar aging issues with the rubber parts on our DSLRs and weather resistant lenses?
Does anyone here have experience of maintaining gear with rubber seals over this length of time?


Well, I searched around a bit and just found this on the "aging of rubber vulcanizates":



http://www.bouncing-balls.com/chemistry_tech_conservation/ageing.htm



which includes this:

"as the temperature rises, the rate of oxidation increases much more than the rate of diffusion so substantial oxidation occurs on the surface and an oxidized (hard) surface skin is formed. As oxidation continues the chain breakdown may become more significant and the hard surface then softens and turns sticky."


Interesting, is it not? Anyone who has kept any rubber item for any length of time, whether it is a rubber plug for a sink, a rubber/foam grip for a tennis racquet or just a pack of rubber bands, will have seen the hard surface skin if not the turning sticky.

So, looks like there is nothing we can do about it; rubber oxidises and breaksdown with age.

I'm not a chemist and I don't know the exact material from which Pentax make their eyecups and rubber seals, but we had probably better expect to be replacing seals in the long term.


And it seams likely that if you store your gear in a WARM dry place, you may actually be speeding up the aging and breakdown of the rubber seals!


Regards,
Derek.

Rubber won't last forever and mould gets everywhere in the end - the best you can ever hope to do is prolong the life of equipment!

But you're quite safe in your assumption that you can freely mix your equipment - the unaffected won't go down the same road unless it's kept in similar conditions, and now you know what to avoid I very much doubt that's a mistake you'll be making.

As for cleaning equipment (cameras and lenses) I've always used lighter fluid and it's never let me down yet. Swab it on gently with cotton buds and polish off any residue with a microfibre cloth.

The Motor Industry are massive users of rubber products. These products have to withstand all conditions of temperature and light. From experience, modern rubber components on cars seem to last much longer than they did on older vehicles. Water hoses used to go regularly but now often last the life of the car. So perhaps the Motor Manufacturers have got improved rubber.

I have noticed that Motorists Shops do sell polish for rubber. Whether this improves the life of the rubber, or just beautifies the surface, I do not know.

On the subject of storing camera equipment, I personally give all my kit a few hours of sun, every so often, to kill off the spores and damp. During this process, I also remove the lens caps on the lenses, so that the sunlight can shine through the optics.

The very thought of doing that makes me shudder...

If you are heating up the equipment you are causing all sorts of unecessary heat expansion and I think the potential for serious damage is there.

If I was overheating the equipment then it would make me shudder, but I will not let it overheat in the sunlight.

We get lots of rubber problems in the Gulf, high temps and plenty of UV. For years, I have used ArmorAll to protect door rubber etc. Even use it in the UK to prevent doors seals freezing in winter. I have used it on camera external rubber. It is non greasy and buffs up or not if you buy the matt finish (good for dashboards). It will not atract dust.

Regards

Another word of caution on letting the sun shine through lenses. The house in which I grew up had some bull's eye panes of glass in the windows. One day there was a burning smell and after some hunting around, we found an armchair in the living room smouldering where the sun had been focused on it by the glass.