Workshop Ultrasonic cleaning of video head drums?
Some while ago I bought a small ultrasonic cleaner (about three years ago!) which I have yet to put to any good use, but the thought crossed my mind that it may [or may not] be able to dislodge the heavy and hardened deposits in the head gaps of VCR video heads. Ultimately, I have several Philips N1700 head drums which might benefit.
Obviously, paper labels would need to be removed from the drum, as would any other identifying stickers etc.
because of the small size of my particular cleaner, Philips VCR drums will not fit into the bath, so I'd propose to mount the heads such that the spindle would be horizontal across the top of the bath, with just one head and a portion of the drum's periphery immersed in the solution. this would necessitate rotating the drum and repeating the process. A similar approach could be adopted for VHS head drums, or they could be entirely immersed in the solution.
What I'm less certain of, is what would be the best solution to use for cleaning such parts, and the potential, if any, damage that the ultrasonic cleaning process might cause.
There are any number of commercially available cleaning solutions for other applications, but non that are specifically aimed at our niche market. I guess one could start with just plain water, move on through various domestic cleaners, e.g. washing up liquid, and on to the more invasive solutions like the ones used by the small engine parts cleaners.
I'm also mindful of the mounting method of the Philips heads, bonded with an adhesive, rather than a physical/mechanical mounting method. Also in mind, I wonder about the potential breakage of the fine wire of which the head windings are made - Metal fatigue?
The bottom line simply is, I have several head drums that are at present totally unusable, should we refer to them as blind? and since these things are long out of production, there's not a lot of hope of finding any NOS parts. I've looked at a few under a low powered microscope, and it's patently clear that the head gaps are completely filled with a dark residue (detached magnetic recording surface material). There is no physical means by which to remove the deposits, and ultrasonic cleaning seems to suggest itself - What is there to lose?
Any ideas? Any input welcome.
I used one on my panasonic NV-W1 multistandard recorders drum, just used washing up liquid as solvent with 65 degrees on the water. Could see the muck drifting off from everywhere.
My ultrasonic is a dual frequency having four transducers, two for 25kHz and two for 40kHz
Certainly sounds worth a try, there are many different liquids you can use in it, the ones I've used before are IPA, Ultrasolve (smells a bit citrusy) and one called Safewash, which you mix with water. The last 2 are pretty expensive, and mostly aimed at shifting flux residue off PCB's. I'd give it a go with IPA, maybe test on an old one that's totally useless to make sure it doesn't dissolve any glue!
IPA can be very dangerous in ultrasonics because the vapor it produces can self ignite. Never tried it myself but it would be outside for sure if i did.
In my case it was because it had previously been used with tapes that were shedding, a real mess when i got it but performs flawlessly now.
We use it at work all the time, normally fill the ultrasonic with water, then put the part to be cleaned in a glass beaker with IPA or whatever cleaner in it, which reduces the amount you need. Someone did fill one of the tanks with IPA once, H&S soon got rid of it!!