Ultrasonic record cleaners

@drbond & @lewm,

Please be careful with high concentrations of IPA in water and use with a heated ultrasonic tank.

25% IPA/water has a flashpoint of about 80F; and no ultrasonic tank you can afford is explosion-proof. With an ultrasonic unit three mechanisms are now in play - the heat that speeds up evaporation; the record turning is drawing fluid out that is evaporating, and the ultrasonics are agitating the fluid surface and a mist/vapor is often produced. All of this has the potential to setup the necessary conditions to develop flammable AND explosive vapors. At 100% IPA, the lower and upper explosive limits are 2.3 to 13.2%. But, even diluted with water, at 25% water-IPA, the lower and upper explosive limits are 2.3 to 7.1%. In a common domestic setting, it is very unlikely that the high ventilation turn-over rates that are required in medical and industrial settings that prevent the accumulation of flammable/explosive vapors will be used. So, the risk in a domestic setting is higher.

@drbond,

As written in the book -

VIII.7: KODAK™ PHOTO-FLO 200: This is a wetting agent that is water mixed with a combination of 25-30% propylene glycol (i.e., anti-freeze) that acts as a solvent and as an antibacterial and antifungal agent and 5-10% nonionic surfactant. The nonionic surfactant by the CAS number 9036-19-5 is most likely Dow™ Triton™ X-114. This type of surfactant (octyl-phenol ethoxylates) is an environmental aquatic toxin and is being phased-out (see CHAPTER IX. DISCUSSION OF THE FINAL CLEANERS: for details). If the surfactant is Dow™ Triton™ X-114, the surface tension will be about 31 dynes/cm, the CMC will be 120 ppm, but the low 25°C/77°F cloud-point limits this product mostly to applications equivalent to room temperature.

If you add a cap-full that may be 10-ml, at best only 1-ml of surfactant is added, but (1-ml/6000-ml)(100) = 0.0167% = 167 ppm. So, there should be enough for it to act as a wetting solution. The propylene glycol diluted does nothing other than increases the non-volatile residue which if not rinsed, can leave a viscous type of residue.

My recommended nonionic surfactant is Tergitol 15-S-9 which is a very high-performance surfactant - Tergitol 15-S-3 and 15-S-9 Surfactant | TALAS (talasonline.com). At 1-ml in 6L tank, the 167-ppm will provide excellent wetting and also provide detergency that Triton X100 will not unless you add 3X more - Tergitol 15-S-9 is much more efficient, mixes easier and rinses much easier.

Edit:  FYI - Tergitol 15-S-9 is not the same as Tergikleen - different products and the book addresses in detail the difference in Chapter IX. 

drbond, You have a point about the fact that I do my cleaning in a conventional VPI RCM. And I guess I take the point of antinn that using 25% IP alcohol in a heated US cleaning tank might be dangerous, although that surprises me. However, the fact remains that such a low concentration of isopropyl alcohol as you propose is unlikely to help much, in my opinion. By the way, because of the low concentration of Photoflo as you propose to use it, I have to think that I was being overcautious in mentioning the undesireable additive, which antinn names as propylene glycol. However, antinn seems to agree that other surfactants might work better, e.g., Tergitol. Sorry for any confusion, otherwise.

@antinn 

Thanks for the word of caution about Photo Flo.  Do you know if the solvent in Photo Flo could adversely affect the LP at all?  

One of the best reasons to purchase a degitter is that it has a filter that cleans the water every cleaning cycle. Most other cleaners once you clean the first record the dirty water is returned to the water tank