jlancasterd Posted September 28, 2007 Share #1 Posted September 28, 2007 Advertisement (gone after registration) I see that the latest issue of LFI advises the use of isopropyl alcohol for cleaning the M8 sensor (and, from the context, also that of the DMR). 500ml of isopropyl alcohol to BS1595 costs about £6 ($12) at my local pharmacy - very considerably cheaper than Eclipse E2. However, LFI makes a point of emphasising that the isopropyl alcohol must be 100% pure. Can anyone tell me if BS 1595 isopropyl alcohol is 100% pure? I know from my degree studies (back in the early 1960s!) that it is very difficult to get some alcohols (especially ethanol) of that purity as they absorb water from the atmosphere. LFI also suggests the use of homemade cleaning awabs - a great temptation given that the cheapest ready-made swabs I've found here in UK work out at about £3 ($6) each. Link to post Share on other sites More sharing options...
Advertisement Posted September 28, 2007 Posted September 28, 2007 Hi jlancasterd, Take a look here Sensor Cleaning - LFI advice. I'm sure you'll find what you were looking for!
amigadave Posted September 28, 2007 Share #2 Posted September 28, 2007 Hi John I use HPLC grade IPA from my lab (I ordered 2.5L especially for the purpose of cleaning my sensor ). Not sure about the BS1595, which seems to be a standard for industrial cleaning IPA (so possibly pure enough). If you want a small (up to 100ml) sample of the IPA from my lab, which I have used to clean lenses and sensors, and are in the UK, just let me know. Link to post Share on other sites More sharing options...
Shootist Posted September 28, 2007 Share #3 Posted September 28, 2007 I don't use a home made swap but I do use a plastic spatula like device I bought from CopperHill Images and PEC-PADs. Hard to find 100% alcohol of any type. Link to post Share on other sites More sharing options...
guy Posted September 28, 2007 Share #4 Posted September 28, 2007 FWIW, I've always used Boots basic isopropanol / isopropyl alcohol / propan-2-OL to clean electronic kit and contacts. The music recording industry gets through gallons of it: everything from head cleaning on tape decks to contact cleaning in patchbays. It's great stuff, and most proprietary cleaners are basically it plus something. But I've never cleaned a sensor with it! My *guess* is that it would do the job very well and with no residue. But please don't sue me if it doesn't! Further guess: if it does leave streaks, I'd imagine E2 would clean them off no problem. So unless there's a risk of damaging the electronics – and I doubt that, given how much of it has gone into my synths over the years – it might be worth giving it a go and seeing what results you get. Link to post Share on other sites More sharing options...
jaapv Posted September 28, 2007 Share #5 Posted September 28, 2007 If I recall my high-school chemistry correctly, 100% percent alcohol is so hygroscopic that it cannot exist as soon as the bottle is opened. The moisture in the air will dilute it down to 96% or less. Link to post Share on other sites More sharing options...
jlancasterd Posted September 28, 2007 Author Share #6 Posted September 28, 2007 If I recall my high-school chemistry correctly, 100% percent alcohol is so hygroscopic that it cannot exist as soon as the bottle is opened. The moisture in the air will dilute it down to 96% or less. Yes, that's my recollection - but does 'alcohol' in this context mean only ethanol? Link to post Share on other sites More sharing options...
amigadave Posted September 28, 2007 Share #7 Posted September 28, 2007 Advertisement (gone after registration) Isopropyl alcohol forms an azeotrope with water at 88% IPA/12% water by weight (96% ethanol/4% water for alcohol). Anything higher than 88% IPA has been azeotropically distilled. I'm not sure how hygroscopic IPA is, so if you left a 100% IPA "solution" out on the bench it might draw water from the atmosphere over time, or it might not. If you keep it in an air-tight container, you should be OK though. Link to post Share on other sites More sharing options...
carstenw Posted September 28, 2007 Share #8 Posted September 28, 2007 Isopropyl alcohol forms an azeotrope with water at 88% IPA/12% water by weight (96% ethanol/4% water for alcohol). Anything higher than 88% IPA has been azeotropically distilled. I'm not sure how hygroscopic IPA is, so if you left a 100% IPA "solution" out on the bench it might draw water from the atmosphere over time, or it might not. If you keep it in an air-tight container, you should be OK though. Wow David, that was your second post. I wonder what the first was like Care to translate? Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted September 28, 2007 Share #9 Posted September 28, 2007 Now that is a man that took some chemistry classes. Going back to the LFI article which i have not read. They actually said make your own swabs. Man not sure i like that advice, heck folks will be putting hankerchiefs in there and who knows what else. i will stick with recommending commercial swabs Link to post Share on other sites More sharing options...
jlancasterd Posted September 28, 2007 Author Share #10 Posted September 28, 2007 Going back to the LFI article which i have not read. They actually said make your own swabs. Man not sure i like that advice, heck folks will be putting handkerchiefs in there and who knows what else. i will stick with recommending commercial swabs I think that they are assuming normal care and the use of non-abrasive camera wipes. I'm not sure that sensors are quite as delicate as we sometimes think. I well remember the first time I saw a working example of the DMR, two or three years ago, at a Leica day at my local Leica agent. I asked the Leica UK Rep doing the demonstration about cleaning the sensor and he promptly whipped the back open and rubbed the sensor with a standard cleaning cloth, remarking in passing that the sensor was hard coated and you could do it with the end of your tie, provided you didn't press too hard... Not sure I'd want to follow that last bit of advice, but he was making a point. Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted September 28, 2007 Share #11 Posted September 28, 2007 Exactly it is cover glass but you never know what some people may stick in there. Link to post Share on other sites More sharing options...
etrigan63 Posted September 28, 2007 Share #12 Posted September 28, 2007 What issue of LFI are you guys reading? I just got the 6/2007 issue and there is nothing in there about sensor cleaning that I can see. Am I suffering from Juvenile-Onset Alzheimer's? Link to post Share on other sites More sharing options...
Guest Posted September 28, 2007 Share #13 Posted September 28, 2007 Hello A leica M8 costs £3000 or there abouts .A bottle of eclipse 2 ( 59 ml ) costs £ 8.45 ($16) and will last at 4 drops per clean for a few years at least.It comes in a handy bottle.Sensor swabs cost £3.0 / $6.0each and are perfect for the job.Why use anything else?.The cost of problems caused by using products which are not proven is surelly not worth the risk. Brian Link to post Share on other sites More sharing options...
jlancasterd Posted September 28, 2007 Author Share #14 Posted September 28, 2007 What issue of LFI are you guys reading? I just got the 6/2007 issue and there is nothing in there about sensor cleaning that I can see. Am I suffering from Juvenile-Onset Alzheimer's? LFI 7/2007 (September-October) pages 50/1. Link to post Share on other sites More sharing options...
Dan States Posted September 29, 2007 Share #15 Posted September 29, 2007 Isopropyl alcohol forms an azeotrope with water at 88% IPA/12% water by weight (96% ethanol/4% water for alcohol). Anything higher than 88% IPA has been azeotropically distilled. I'm not sure how hygroscopic IPA is, so if you left a 100% IPA "solution" out on the bench it might draw water from the atmosphere over time, or it might not. If you keep it in an air-tight container, you should be OK though. Yea, I really like India Pale Ale too, but I'm not sure it would all come off the sensor. Something really light like Zima might be ok. Link to post Share on other sites More sharing options...
gmaurizio Posted September 29, 2007 Share #16 Posted September 29, 2007 I see that the latest issue of LFI advises the use of isopropyl alcohol for cleaning the M8 sensor (and, from the context, also that of the DMR). 500ml of isopropyl alcohol to BS1595 costs about £6 ($12) at my local pharmacy - very considerably cheaper than Eclipse E2. However, LFI makes a point of emphasising that the isopropyl alcohol must be 100% pure. Can anyone tell me if BS 1595 isopropyl alcohol is 100% pure? I know from my degree studies (back in the early 1960s!) that it is very difficult to get some alcohols (especially ethanol) of that purity as they absorb water from the atmosphere. LFI also suggests the use of homemade cleaning awabs - a great temptation given that the cheapest ready-made swabs I've found here in UK work out at about £3 ($6) each. Isopropylic alcohol like the one found in pharmacies has water in it. Not much, but useless for cleaning sensors. You need something that dries fast. You need ANHYDROUS ALCOHOL, only can get it at chemical supplies stores. Methilic (1 carbon atom per molecule) is the one in Eclipse, the fastest drying one and therefore the one recommended. Ethilic (2 carbon) is tough to get because people add sugar and drink it (DO NOT DRINK METHILIC ALCOHOL, WITH LUCK YOU ONLY GO BLIND). Isopropilic (3 carbon) is the one used in pharmacies and drug stores. Does not dry fast and has water unless it is marked as 100% or ANHYDROUS (meaning NO WATER). Link to post Share on other sites More sharing options...
amigadave Posted September 29, 2007 Share #17 Posted September 29, 2007 Wow David, that was your second post. I wonder what the first was like Care to translate? Haha, does it show that I'm studying chemistry? An azeotrope is a mixture of two or more compounds that does not change composition on boiling. So, if you try to distill ethanol (alcohol) you can only reach a maximum of 96% ethanol/4% water, as at that point the vapour above the solution is also 96% alcohol/4% water. Therefore, no change in composition on boiling (or distillation). Any ethanol solution above 96% has had water removed past this point by other means, such as molecular sieves, or addition of another chemical, to "break" the azeotrope. A solution of ethanol that is over 96% is hygroscopic, leaching water from the atmosphere until it returns to the 96%/4% azeotrope. IPA may or may not be hygroscopic, but I suspect that it would be. BrianP: I've always used a microfibre cleaning cloth on the end of a chopstick for all sensors and lenses. I use IPA to get any grease off that is too stubborn to move without gentle poking. It doesn't scratch glass or take coatings off, so why would it damage the (admittedly thin) coverglass on an M8 sensor? Dan States: IPA is wonderful (the beer that is!). Much better when brewed at home (especially using deionised water from the lab). gmaurizio: I'm not sure that an IPA/water solution is bad for cleaning a sensor. The presence of water doesn't necessarily decrease the volatility (i.e. rate of evaporation) of the solution. In fact, the azeotrope of IPA/water may be more volatile than either IPA or water (as is the case for the azeotrope of ethanol and water). However, anhydrous IPA would dissolve any water-based residue on the sensor, so could be more effective at cleaning than the IPA azeotrope. Link to post Share on other sites More sharing options...
Kent10D Posted September 29, 2007 Share #18 Posted September 29, 2007 Just speculation, but I'm guessing it would be pretty near impossible to get totally anhydrous alcohol anywhere near the sensor. By the time you have a few drops soaked into the pad or whatever you're using, it would be in contact with so much air and the moisture it contains throughout the fibers of the pad that it would have already absorbed as much water as it could before you even started wiping. The pads themselves probably contain a certain amout of water too. Refutation or comment from chemistry majors welcome. Link to post Share on other sites More sharing options...
guy Posted September 29, 2007 Share #19 Posted September 29, 2007 HelloA leica M8 costs £3000 or there abouts .A bottle of eclipse 2 ( 59 ml ) costs £ 8.45 ($16) and will last at 4 drops per clean for a few years at least.It comes in a handy bottle.Sensor swabs cost £3.0 / $6.0each and are perfect for the job.Why use anything else?.The cost of problems caused by using products which are not proven is surelly not worth the risk. Brian Must say I agree with this! And despite having 500ml of isopropanol sitting in my desk drawer right now, I wouldn't use it in my M8. Link to post Share on other sites More sharing options...
amigadave Posted September 29, 2007 Share #20 Posted September 29, 2007 Just speculation, but I'm guessing it would be pretty near impossible to get totally anhydrous alcohol anywhere near the sensor. By the time you have a few drops soaked into the pad or whatever you're using, it would be in contact with so much air and the moisture it contains throughout the fibers of the pad that it would have already absorbed as much water as it could before you even started wiping. The pads themselves probably contain a certain amout of water too. Refutation or comment from chemistry majors welcome. I'd agree with that, although as I said, I'm not sure how hygroscopic anhydrous IPA is. It might take up as much water as the solution will hold almost instantly (probably true if soaking through a material with a high surface area, e.g. a swab), or maybe it will take several minutes/hours. Link to post Share on other sites More sharing options...
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