Mouldy VHS cassette removal?
 

Hello,

I know there are quite a few threads here already on the subject of mouldy VHS cassettes, and I have spent time going through them, but there are still one or two specifics I’m still unclear about. Forgive me if I’ve missed something.

For context, I’m not an AV professional; just an enthusiastic amateur who knows his limitations and who’s happy to ask the experts when necessary. I have a simple workflow that suffices for my very modest needs. I’m located in Ireland: small country, small population. Therefore, niche specialist services — guaranteed reliable ones in particular — can be hard to come by. If there are any professional VHS conversion services here who can handle mouldy cassettes I’ve been unable to find them, although I’ll be delighted if anyone can enlighten me on that score. (Also, for completeness, national standards are PAL, with a mains supply of 230V / 50Hz.)

A friend of mine has asked me to digitise a small number of cassettes. Not a business transaction, just a favour. The cassettes carry unique, original private/non-commercial recordings which are of sentimental value. They came from two different sources and it shows. Most of them have been stored well and are pristine but eight appear to have light mould colonies on the surface of the spools. Naturally, I haven’t played or dismantled them yet.

This thread:

https://www.digitalfaq.com/forum/vid...vhs-tapes.html

informs me that it might not be mould at all but it seems prudent to err on the side of caution and assume the worst.

So I have a choice.

1. Get the cassettes cleaned professionally (and possibly digitised, while they’re at it). If there isn’t a suitable operation in Ireland, the only realistic alternative would be one in Britain. I’ve found the web sites of two companies there that offer this kind of service. I’m unsure about digitalfaq’s netiquette regarding posting company names and URLs, however, so I’d rather get the approval of a moderator before I do that. It’d be great if there were someone here who’d used one or both of these companies (or some other UK-based concern) and who could recommend them based on experience. Cost would be a BIG factor though. £200 or thereabouts per-cassette may be do-able. Four figures a piece probably isn’t.

2. Do the job myself.

Buying a specialist VHS cassette cleaning machine isn’t an option. Making one up from a sacrificial desk probably is.

These threads have been particularly helpful:

https://www.digitalfaq.com/forum/vid...-mold-vhs.html
https://www.digitalfaq.com/forum/vid...ideotapes.html

but I’m still unclear regarding some of the details.

As far as I can tell, a long, fiddly, meticulous and boring two-stage process of exposing all the dismantled parts of the cassette to UVC and then washing them in >90% isopropyl alcohol seems to be the preferred method. (All done outdoors, upwind, masked, spooling the whole tape through foot by foot, letting it dry et-c…)

The UVC stage is intuitively appealing but what bulb wattage should you use? And for how long? In this thread:

https://www.digitalfaq.com/forum/vid...-mold-vhs.html

Lordsmurf suggests this 25W one as a possibility:

https://www.amazon.com/Germicidal-Li...dp/B07KYV687N/

but as far as I can see, there was never any agreement as to whether is was suitable or not; that is, is it too strong / strong enough to use on magnetic tape and on the workings of VHS decks?

And LightWorker01 suggests 20-30 minutes of exposure to sterilise decks. (So it’s probably reasonable to use the same duration for all cassette components other than the tape itself.) But “no longer than a few minutes” to sterilise the tape is rather unclear. Less than 20 minutes, obviously, but, well, how long’s a few minutes? Unique recordings — I want to kill the mould but I don’t want to ruin the carrier in the process!

It’d be easy enough to make up something similar to the UV box that appears at about 18.50 in this video:

https://www.youtube.com/watch?v=FaeIQ59rQpE

but you’d need to know specifics, for this application, regarding bulb strength and exposure duration.


The isopropyl stage seems more straightforward, even if it is the most fiddly:

* Take the previously dismantled and UVC-treated cassette.

* Soft brush to clear away surface mould.

* Dump all cassette components except the tape and spools into a >90% isopropyl alcohol bath and leave them there for an hour, agitating if necessary to dislodge surface air bubbles.

* Meticulously wash the tape with >90% isopropyl alcohol and then dry, foot by foot, as described in other threads.

* Dry the whole lot and reassemble.

So, do I have a reasonable take on how to go about recovering these mouldy tapes and and can anyone help fill in the details concerning wattage and durations?

Thanks in advance :)

All the clarification you need:

https://vhsislife.com/got-mold-lets-fix-it/

and here:
https://www.youtube.com/watch?v=OtDT...FjaGluZSB0YXBl

I'm not sure UV does a whole lot - it'll probably kill living mold, but most tape mold is probably long dead. I'm not sure if it'll actually weaken the structure of the mold. What is more likely to weaken it is probably apply some alcohol directly to the mold which can be done with a light wipe to the wound tape on either spool by slightly flexing the spool edges away to get a thin cloth in there.

But that's not speaking from experience, I've not really had to deal with moldy VHS tapes yet oddly enough. Phil from gotmomories does it this way and then moves over to a device that predates the VHSislife cleaner but operates the same. I disagree with plenty of his methods, but for tape mold, that does seem like it would be a better way to initially knock most of the mold down before doing the finer passes with essentially a tape rewinder and cleaning pads on either side which is what the vhsislife cleaner is.

Can't really beat the VHSislife cleaner for a ready built kit (you'll need to wait though since there's a wait list), but you could come up with something similar yourself if you like to tinker: https://youtube.com/shorts/2aZd5HMtJ...fcmzoRmrXHQ5HH

The few moldy tapes I have are full size U-matic. They do sell hubs for U-Matic for it, but the project owner/developer says it's just for the compact U-Matic tapes.

Here's another simpler example of a DIY one that remains in the rewinder: https://youtube.com/shorts/L6wIl7yWK...UGIRN24QhOuy2A. Whether the rollers spin or not is kind of up to you.

This is a terrible device as-is. I left a comment on Video99's review:
Assuming the mold is all dead is a bad assumption, and often false. It takes a lot of kill mold.

From a simple Google search:
... but I still remember Biology 101 from high school. :cool:

I wanted to make those quick comments, I'll reply back to the OP again soon.

Valid points, I suppose best practice would be outdoor use only with a large fan blowing at it from behind or to use under a fume hood with negative pressure, or even in a sandblasting cabinet or similar while wearing an N95 mask. Problem with UV is that it won't get to the mold on the underside of the tape spool and different top plastic spools may not allow much UV to pass through them.

Something I don't know if has been tried is ozone gas first in a ziplock bag (ozone generators are pretty cheap), though I can't say for sure that ozone won't react with the tape itself as the tape probably contains some organic molecules and the magnetic media no doubt has some metal content. Would be quite easy to test though, just take a non-critical throw away tape and expose it to ozone for 5 minutes and see how it plays afterwords. If it starts shedding a bunch of oxide or has a bunch of dropouts it didn't originally have, then the ozone method would obviously be a no go. From what I'm reading, high ozone exposure can kill just about any mold in about 2 minutes.

As far as testing for effectiveness, should be able to just swab the tape surface where there's obvious visible mold and see if it grows on a petri dish after the ozone treatment. Could also do a separate dish test on the same tape in a different spot from before treatment to prove that live mold spores should grow on that media.

There are other chemicals you could directly apply to the mold that would kill it just about instantly, but most of those tend to be corrosive and would probably damage equipment while also being hard to completely remove from the tape after. Ozone gas on the other hand should diffuse out of the tape if left to rest in room air overnight I would think. Or if there's concern that it wouldn't, you could put the tape into a high vacuum for a few seconds and that'd get rid of it for sure. High vacuum won't kill mold though.

I'd say you could probably bake the tape first, but looks like you need something like 160 degrees to kill mold and most tape baking is done more at like 140F. You do run the risk of demagnetizing your tape to some degree the higher in temperature you go as well.

Also, from the EPA:
This is very correct, and I've pointed that out since these discussions started.

But another valid point made was that 95%+ of the mold is on the surface of the spool, not between the tape. The mylar tape sandwich is not conducive to life of any kind, not even mold. It's surface mold, and needs oxygen.

You do often see mold damage on the tape itself (on the recorded surfaces), but it tends to be byproduct, and irremovable. With videotape, it's permanent damage. It's not necessarily mold itself, but more like mold piss/poop left behind (not exactly that, but essentially).

Well now, you just volunteered for some testing! :P

Err, two tests. :laugh:

But again, remember what the EPA (and science, bio) says:
So, you do both.
Sort of like TBCs. It's not a "pick one" scenario. Both are required to be proper and effective. Otherwise, you're just half-assing it, hoping for the best (and often failing).

Yeah, this all gets complicated fast.

Youtube/Reddit are full of self-proclaimed "experts" that do some truly risky BS. Mold removal from VHS tapes is one of them. (That's because both sites are filled with the general population, and the general pop has a large % of morons. Yes, those people walk among us! Scary!)

Even I don't mess with mold, and know when to pay the experts. I'd rather let SpecBros make these experienced educated evaluations, and perform the task to the best of their ability. Whatever I could do -- whatever the Youtubers do -- will be vastly inferior. My health, and the sanctity of the tape contents, matters far more.

What gets me is when I see somebody asking about mold on an old copy of a ready-available retail tape. Buy another copy! I'm amazed at the great lengths some people go to in order to avoid buying something. End result is they'll actually spend MORE money, and MORE time, for the dumbest of reasons.

FYI, this site has/had some medical professionals on it. When my violent allergy hit years ago, and I posted about it, some of them contacted me with stories of their patients. (Due to fear of HIPAA, even though nobody was named, they didn't want to post the story in public, in case details would identify.) And thank you to those same doctors who sent me masks during the Covid-19 shortage in March 2020!

Thanks, everyone, for all the prompt responses. They’ve given me a lot to think about. It does, indeed, get complicated fast! The VHSislife cleaner looks interesting as an alternative to a modded sacrificial deck. That said, even with the suction I’d still be inclined to use it masked, outdoors and upwind.

Useful reminder that optically transparent tape spools will probably be opaque to UV. I’m starting to think that UV treatment is really best considered just a supplement to wet cleaning with isopropyl.

Given the nature of the recordings on the cassettes I have, I’ll be giving this a lot more thought before I do anything practical.

Thanks again :-)