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AlanJones
19th June 2012, 02:58 AM
I see that this subject has cropped up in the great 'to squeegee or not to squeegee' debate. It is a new topic and should be treated as so.

I have been doing a lot of dry reading on this subject and also on infections in lenses as of late, making notes and will get them commented on by the Microbiology Department at the university here, where I have friends.

Anyone interested in this topic should read the 'Kodak Service Pamphlet AE22 dated July 2002' which will give a good basic understanding of the topic. But what they don't tell you is that their films, Ektachrome in particular acts as a magnet for these spores they really loved the gelatin and the dyes in the film and bred profusely in it. Kodachrome was not as bad and I have not got as far as colour neg materials yet. Agfacolor slides I had in a box with particularly badly infected Ektachrome slides were unaffected and I am no fan of the little yellow box.

Someone mentioned Formaldehyde in the stabilizer, well not so, since the early 1990's where it is included in the conditioner pre-bleach bath as a dye preservative. At the same time, the stabilizer solution contained a surfactant and anti-fungal agent along with the detergent to promote even drying. Trade name is Monistat and it has pharmaceutical applications in preparations for oral and vaginal thrush. There's yeast in poo!

Now I'll try and include a link to the leaflet:
1417

CambsIan
23rd June 2012, 07:28 AM
Hi Alan,

Thanks for the link, most interesting.

Ian

marty
23rd June 2012, 08:05 AM
Hi, there. Very interesting link, thanks for sharing it.

Cheers, M.

DavidH
23rd June 2012, 06:04 PM
I have some Agfa slides circa 1972 with mould growth. I have wondered about removing it. So far I have left it alone due to the high probability (or so I imagine) of making a bad situation worse. I would be grateful for suggestions from anyone with experience of de-moulding slides.

AlanJones
24th June 2012, 11:35 AM
David,

I am interested to hear about your mould growth on Agfa. I take it that your slides were from a film that included the cost of processing by Agfa (then)?

My oldest Agfa slides in the boxes with the Ektachromes that were very bad were from the 1962 - 1968 period. From then until 1980 I did very little photography and what I did tended to be print film. Then, in 1980, I bought a new OM system camera and started using 'Agfacolor Professional' film which was around then for a few years. Again in about 1988 I hung up the camera until about 2005. I have no mould on these Agfa slides and perhaps they are still too recent to tell yet.

Sorry to hear your slides are ruined, you can do something to make them look better but they will always show marks. The question you have to ask first is simply 'is it worth it'. Having tried on a few Ektachromes, I thought it was not and binned them.

DavidH
25th June 2012, 02:14 PM
The Agfa slides were indeed process paid. So far as I can remember, they have not been subjected to conditions any different to those of other makes that I have, although admittedly, they are the oldest. They also seem to have faded.
For some time I used a postal firm in Diss that was cheaper tha the established brands. I don't know what make of film they used as it was re-packed under their own name, They seem to have survived O.K.
As for the Agfa slides, I think I'll leave them alone and maybe copy them. A poor slide is better than none at all.

Ian Marsh
25th June 2012, 03:33 PM
I would say that the make of film has very little to do with whether they have mould. There can be several reasons for growth, but typically they need a high relative humidity (above 60%) to grow.

A possible reason is that the slides were packed (sealed, effectively) into a closed environment before they were fully dry, (rushed) this would provide a suitable environment when warm.

If you have slides in boxes it would be good practice to open them lay the slides out to get some dry air circulation and package them again, this is where looking at our images can actually help to preserve them,

As to removal, mould is an organism that actually feeds on the emulsion, so once it is badly effected it is gone

PaulBJE
28th June 2012, 12:46 PM
Just slightly off thread, or maybe not, I have been developing colour prints recently using a Nova heated slotty thing. Last couple of times when I have removed the keeper on the stop bath slot there has been greeny mould/algae floating on the top! I have removed it with tissue but there must be some left in the solution. It does not seem to affect the prints and the developer and fix/bleach are unaffected. Has anyone else come across this? I am developing at 35 degrees and when I finish I replace the keepers and cover with cling film to reduce fumes.

The stop is Ilfostop diluted 1:9

PaulBJE

Dave miller
28th June 2012, 01:16 PM
Just slightly off thread, or maybe not, I have been developing colour prints recently using a Nova heated slotty thing. Last couple of times when I have removed the keeper on the stop bath slot there has been greeny mould/algae floating on the top! I have removed it with tissue but there must be some left in the solution. It does not seem to affect the prints and the developer and fix/bleach are unaffected. Has anyone else come across this? I am developing at 35 degrees and when I finish I replace the keepers and cover with cling film to reduce fumes.

The stop is Ilfostop diluted 1:9

PaulBJE

Please clarify that you are switching the unit off at the end of a session or leaving it on. :confused:

PaulBJE
28th June 2012, 03:03 PM
Please clarify that you are switching the unit off at the end of a session or leaving it on. :confused:

Switching it off, Dave. I coudn't afford the electricity to leave it on permanently!!!!

Paul

AlanJones
29th June 2012, 12:23 PM
Ian, I think you are being very brave to state that 60% is the RH that these spores germinate, unless you have something in print from an acreditable source. The consensus here in Cambridge is that it is much lower, possibly 45 to 50%, but again nothing in print. (Film conservators in Cambridge University Museums, informal chat.) But, I want to get to the bare bones of this one and I see RH as the key issue. I have a hygrometer and in the spell of warmer weather we had in May it was showing 19%, yesterday 28.06.12 when it was thundery here is was 29%, today, less humid it is slipping back down again to 26%. It has never been higher than 32% ever. For me, I assume modern living has designed out the need for me to worry too much about mould issues unless I move home to somewhere it is damp, like an old property.

Regarding drying time, my own films were hung up next to our coal fired room heater/central heating boiler for at least a day before mounting. In my student days, I worked for Gevaert as a lab technician attached the reversal and cine film processing lab. Here the slide films were blasted with hot air at about 110 deg F for about 20 mins before going upstairs for mounting. No drying problems in either case.

Dave miller
29th June 2012, 01:16 PM
Ian, I think you are being very brave to state that 60% is the RH that these spores germinate, unless you have something in print from an acreditable source. The consensus here in Cambridge is that it is much lower, possibly 45 to 50%, but again nothing in print. (Film conservators in Cambridge University Museums, informal chat.) But, I want to get to the bare bones of this one and I see RH as the key issue. I have a hygrometer and in the spell of warmer weather we had in May it was showing 19%, yesterday 28.06.12 when it was thundery here is was 29%, today, less humid it is slipping back down again to 26%. It has never been higher than 32% ever. For me, I assume modern living has designed out the need for me to worry too much about mould issues unless I move home to somewhere it is damp, like an old property.

Regarding drying time, my own films were hung up next to our coal fired room heater/central heating boiler for at least a day before mounting. In my student days, I worked for Gevaert as a lab technician attached the reversal and cine film processing lab. Here the slide films were blasted with hot air at about 110 deg F for about 20 mins before going upstairs for mounting. No drying problems in either case.

Remember that the Relative Humidity is a factor of both temperature and environment. According to the weather office today it is about 65% but will rise to about 85% tonight. In the UK it would be very unusual for the RH to fall below 45%.

Ian Marsh
29th June 2012, 01:49 PM
Here are a couple of links regarding RH and mould growth

http://cool.conservation-us.org/bytopic/disasters/primer/npsmold.html

http://epi.publichealth.nc.gov/oii/mold/conditions.html

I have aways believed that safe storage for most organic things is a temp of 20º c and RH 50-55%

It is important to understand that RH will fluctuate with temperature as warm air holds more moisture. If for instance the amount of water in the air (the absolute humidity) Stays the same As the temperature falls the RH will rise. as it rises there are two ways to reduce it either by heating the air or my removing water from it.

But as we are aware science is constantly reviewing things and I may be wrong, but having been involved on the edge of conservation these have been the guide lines that have been generally accepted

AlanJones
30th June 2012, 03:21 AM
Dave and Ian, thanks for your replies. Really interesting links, thanks Ian.

Home for me is a top floor flat just out central Cambridge and I am de-humidifying. A couple of years back I managed to get £110 off a Honeywell de-humidifier in an Argos post Christmas sale. Without it, heat would be unbearable here especially when humid in Summer. It is sufficient to treat 12,000 cubic feet and is close on the volume of the flat and takes 2kWh to run. Expensive, so I use it intermittently, when I am in, usually about 8 hours a day. If water has anything to do with humidity in my local area I have The Vicar's Brook and Hobson's Conduit feet from my flat and River Cam less than a quarter mile away.

As a second line of defence, I have indicator silica gel in the cupboard where I keep my developed films and camera gear. The orange coloured silica gel turns dark green when it has absorbed all the moisture it will. Then it is a case of undoing the bags and emptying out the contents into a saucepan and drying it out with minimal heat on the cooker hob and re-bagging when it has turned back to orange. Anyone wanting this product it is available on ebay, (Supplier: cazboot-001 in Llanelli, Sth Wales. 7 x 100g bags for £8.99 post free.)

I won't say anything more to other readers than I usually look at the silica gel weekly until it shows signs of changing colour, then perhaps every two days after. Conditions will vary. The humidifier is best looked at daily, if missed it could overflow. .
. . a mistake I made just the once, resulting in a wet carpet.

Ian Marsh
30th June 2012, 10:19 AM
Alan

You are doing everything right and more so than most of us.

If you wanted to take things further you could look at data loggers to see what is happening over a period of time, you will probably be amazed at the fluctuations that occur we use these. Well an earlier version.

http://www.preservationequipment.com/Store/Products/Equipment-$4-Tools/Instruments-$4-Meters/Tinytag$9Temperature-and-Humidity

(Sorry this does not seem to work as a link, you may need to copy and paste it to your browser)


Silica gel is a great idea, but even that has moved on, see here.

http://www.preservationequipment.com/Store/Products/Conservation-Materials/Other-Materials/Pelsorb

AlanJones
22nd July 2012, 11:13 AM
I think it now safe to say that we have covered this subject as far as we need to, despite further reading and asking questions on my part.

We have to accept we can't stop the spores from getting on the film, but we can stop them from germinating and causing a problem by keeping them in a dry environment. For those looking to monitor their situation and buy a hygrometer to indicate 'relative humidity', they cost from £10.00 and ebay is a good place to start to look.

For those with ruined slides or negatives, it is a case of if all else fails, I would think improvement can be obtained to get a good result by digital means. A good place to start looking is Wikipedia|Digital Scanning for film. As I have said, 'If all else fails'.