Room Humidity / Static Issues

[PMST]

I live in Bulgaria and winters are very cold, and we have no central heating. This means dry, cold days with an oil radiator on, making humidity about 20%. I have a humidifier in my room but in these conditions it can only get it up to about 25%. Also i use the the usual anti-static gun etc whilst cutting if needed, with talc up the tube if needed.

These conditions cause huge static issues and too many wasted blanks. Does anyone have any other advice, or something i may not have thought of to help fix this? It's only in winter it happens, but very frustrating.

[alesfer]

What kind of antistatic liquid do you use?

[PMST]

I use Souri's

[PMST]

80% of the year is fine, its just battling winter, it has been the same for the past 4 years while living here, i'm unsure if there is anything i can do bar get a sealed house with constant central heating, but hoping for radical ideas

[boogievan]

What static issues, specifically? Dropping chip? ...lots of dust that won't blow off with a bellows?

[PMST]

Dropping chip is the main issue, ive checked and replaced the vacuum system and can confirm it is working fine

[Phinster]

are you cutting on lacquers?

[boogievan]

My hygrometer is showing 20% all Winter, and I think it's because it doesn't show numbers below 20. ); I used to worry about the humidity in the room to the point of following Sean Davies' advice of leaving a bucket filled with water (and a drop of Dawn to prevent 'ponding'), which didn't make a dent in the room's RH, btw, and also using a space humidifier, sitting close to the turntable, which seemed to help with the swarf. But what really helped was getting the suction tube nozzle as close as possible to the surface of the disk and pretty close to the stylus, but without the hiss making a whistling sound, of course, in the groove modulation. MDCs here don't need 100% of the 1/2-Ampere of heater-wire current that Apollo-made lacquers did, but they seem to work fine around 97% of 1/2-Amp... So, I wonder if simply repositioning your chip removal instrument and/or adjusting the stylus heat would have similar results. I no longer consult the cutting-room hygrometer - although I still keep lacquers in a humidor, down the hall, until right before I cut on them.

[dmills]

An ioniser might help.

You want one that makes both kinds to reliably to this, but they are tried and tested technology in the electronics industry for static control of insulating surfaces.

[PMST]

Thanks everyone, problem solved!

Firstly, its 'mainly' a static issue, fixed by adding one more small humidifier and also if severe, some extra liquid mid cut, which is working fine (thanks Bobi!)

A bigger issue i uncovered is that this year, i am cutting over 3 lathes (all VR with SP10 MKIIs), whereas last year was 2. I noticed the newest lathe has a smaller vacuum tube taking the chip, a thinner diameter, so i swapped it out for bigger pipe matching the other 2 other lathes and the issue just vanished. So i can only assume this bigger issue was due to uneven load with the vacuum, which is one big side channel blower taking all 3 chip jars into one hose. The lathe with the smaller tube going to the cutter head was having 90% of the issues.

So the issue is now back to normal, low humidity and some dropped chip now and again but nothing major, and i no longer have to pull my hair out wasting time and blanks.

[boogievan]

It's interesting that low humidity is being blamed. I'm certainly not fibbing when I state that my room is below 20º RH, all Winter and Summer, with only Autumn and Spring showing a higher reading, but the chip-pickup is now excellent, where lacquer coating evenness permits, despite the dryness of the cutting room.

I was going to ask about the suction and nozzles. Mostly we see the flattened oval shape nozzle which permits very close positioning of the mouth of the nozzle to the blank record surface, leaving only the smallest amount of 'daylight' - not even enough for the 'string' of swarf to get past.

Also, it's helpful to have the pump run full speed for a rev and a half of the turntable upon dropping the stylus into the blank. Then the pump speed can be slowed down to whatever keeps it working while more quietly doing so. But the initial suction being strong helps to grab the chip.

Next, is the run-out of the platter being made as horizontal as possible (wrt the spirit level bubble and feeler gauge indicator) so that the nozzle is above land that is only moving horizontally. For the kind of closeness to the blank (by the nozzle's mouth) of which I speak, it would have to be revolving purely horizontally, though (e.g, +/- 1 thou. of an inch).

Finally, the flatness of the surface of the blank, itself. You can't always control that, but Sean Davies mentioned using a razor blade to shave off 'crowns' that may bulge above the rest of the land in order to make the blank record flatter. He claimed that lacquers have always been of variable quality -- even when they were made by Capitol and Pyral.

- Tschüß

[PMST]

It's interesting that low humidity is being blamed. I'm certainly not fibbing when I state that my room is below 20º RH, all Winter and Summer, with only Autumn and Spring showing a higher reading, but the chip-pickup is now excellent, where lacquer coating evenness permits, despite the dryness of the cutting room.

I was going to ask about the suction and nozzles. Mostly we see the flattened oval shape nozzle which permits very close positioning of the mouth of the nozzle to the blank record surface, leaving only the smallest amount of 'daylight' - not even enough for the 'string' of swarf to get past.

Also, it's helpful to have the pump run full speed for a rev and a half of the turntable upon dropping the stylus into the blank. Then the pump speed can be slowed down to whatever keeps it working while more quietly doing so. But the initial suction being strong helps to grab the chip.

Next, is the run-out of the platter being made as horizontal as possible (wrt the spirit level bubble and feeler gauge indicator) so that the nozzle is above land that is only moving horizontally. For the kind of closeness to the blank (by the nozzle's mouth) of which I speak, it would have to be revolving purely horizontally, though (e.g, +/- 1 thou. of an inch).

Finally, the flatness of the surface of the blank, itself. You can't always control that, but Sean Davies mentioned using a razor blade to shave off 'crowns' that may bulge above the rest of the land in order to make the blank record flatter. He claimed that lacquers have always been of variable quality -- even when they were made by Capitol and Pyral.

- Tschüß

Yes for sure your advice is great, i'm not saying it is only down to static, i'm just saying that whilst its cold enough to snow here, us Bulgarian cutters suffer with static issues each year, the houses are uninsulated, without double glazing or central heating, so many factors such as the weather plays a part in our day to day cutting.

For sure though, like you say, all of these other elements are more so part of it, and the suction tube and possible uneven load fixed it. Bare in mind i am cutting plastic with a diamond, not lacquer with a saffire, so added electrical static charge

[PMST]

Also i realise i didn't mention plastic or diamonds, apologies!

[boogievan]

That's what's different - the friction of the plastic against at least itself and perhaps diamond is something which makes static with it, too? Metals, less so, according to this report:

https://openresearch-repository.anu.edu.au/bitstream/1885/209049/4/Static%20Electrification%20of%20Plastics%20under%20Friction.pdf

Anyway, while it's true that humidity that's above 40 or 50 percent will tend to provide a 'ground' connection to static charges in the air, so static issues in a dry room can be suppressed by adding humidity, it's technically like a Band Aid (; for the air. I mean, it's worth considering the thing that's actually making static electricity in the room, since it's not the absence of H2O. For that matter, although the suspension of many tiny water molecules in the air will tend to provide the path to ground for static charges, the H2O, itself, is not an electrical conductor - something electroforming and electroplating engineers know (and taught me). I thought water was making an electrical connection if, say, a live wire was touching the puddle and then so do, say, my foot. Zaaap! ...and it _is_ the 'water', but it's not the H2O, right? It's the dirt mixed in with the H20 that's a conductor. Pure H20 is a dielectric, but it's very hard to keep pure of contaminants.


So, how's the sound of your plastic cuts? Silent grooves are pretty silent? Diamond is being used for 'hill & dale' modulation (i.e., 'impressing') with its face turned backwards from the normal position for lacquer-cuts? Or are you 'engraving' lateral modulation? Have only cut into lacquer, so far...

Cheers

[PMST]

Yeah a diamond can charge unfortunately making these issues way worse, but it's ok. Cuts are nice, silent groove most of the time, i cut around 500 records each month and is my full time job, so when winter hits, it really slows me down with these issues. 8 hour days turn into 12 hours day, very frustrating! Thanks for all of your knowledge, very helpful. I've only been cutting for say 5 years, so learning all the time, i do it 6 days a week so learning fast, but invaluable info from experienced engineers is always welcome

[boogievan]

You mentioned being located in Bulgaria. My favorite LP is Le Mystère des Voix Bulgares which was cut by the late Robert Ludwig. I looked in amazement at his base depth setting of 1,5 mils groove-width for silence (only 38,1 µm across the top!), because this was a very popular pressing that had no reports of problems by end users. We think of 2 mils (width) for the base depth as being sort of stingy, though doable, while 1,5 is certainly skating a fine edge. However, the 0,7-mil radius of the standard conical tip has more than double the tip-width in such a groove, so, he proved it's not insane. 0; Fwiw, I read about a guy with a Scully that could go to 800 LPI and cut at only 1 mil width for silence during long classical sides for Mercury Living Presence (mixed by, our Ampex List friend, Tom's mother, Wilma Cozart Fine, from 3-track tapes of 3-mic'd orchestras down to 1 or 2 tracks...depending). So how much land is left between turns of the groove when it's cut at 800 LPI and when using a 1-mil groove? 0,25 mil! (i.e. 6,3 µm); smh
This is because 1/800 LPI = 0,00125 (in inches), and we're using the 1,00 mils for the aforementioned groove, with just the 0,25 mils left in between its turns.


P. S., if you get a chance, I'd like to see a photo or more of your plastic records (with groove cut in)... Also, your lathe, господине.

Благодаря ти!

[Dub Bull]

That master-cutter[ist] (with the 800-LPI Scully) would be George Piros.

http://www.soundfountain.com/amb/mercury.html