In need of tips, advice and suggestions for pressing records

[PincheBolillo]

Hi everyone, I'm brand new here and have been a record press operator at a small record pressing plant for the last two years. We run Viryltech Warmtones and I'm here today to ask for tips, suggestions, advice, tricks, etc. on how to really press a high quality record. I hate to say this, but I feel in my gut that the way I and all of the other press operators have been taught is pretty piss poor. Our records look and sound pretty good, but there's always stupid, annoying little flaws that we couldn't resolve 100% or had no idea how to resolve and while everyone else at the plant seems to be okay with this, I'm not. I'm the rebellious, crazy one who like to experiment with different settings to see what happens because I know we can do better.

So here's some basic info.
We have 4 Viryltech Warmtones that connect to one Miura boiler and a massive chiller (and I can't remember the name of the chiller manufacturer). Our boiler is set to roughly 145 PSI and will fluctuate from that number up or down by about 10 psi.
Our chiller is set to 67° F and our outgoing temperature from the chiller is usually 68°-75° on average. If it gets hotter, then we stop the machines and drain the warm water out of a big black plastic tank in one corner of our plant until the sides of the tank are cool to the touch and the outgoing temperature on the chiller is around 68°-70 or so degrees Fahrenheit.

Now onto the presses...

The guy who trained me and all of us press operators is the press operator who has worked here the longest. He never sought the advise of old pros who have pressed records for decades. Instead, he took what he was taught, had a stretch of time where there was a lot of trial and error on his behalf and eventually came up with a method of running the presses that he's satisfied with and this is the way we all have been trained to run the machines.

1. Extruders temps should be somewhere between 275°-285° fahrenheit. No gradual build up on temperature across the three extruder barrels, just keep them all around the same temperature.

2. For starters, warm up your molds for 8 seconds, set the dwell to 3 seconds, cool the molds down for 11 seconds and set post dwell to 0. If there's noise on the lead-ins, turn the warm up time on the molds higher. If you see stitching, turn down the cool down time on the molds lower to maybe 10.5 seconds. Our machines are capable of applying 2,400 PSI of pressure, but don't set it that high. Keep it around 2,000 PSI.

The end result are records that made with a cycle time of 30 seconds or less, consistently look pretty good and sound pretty good...but have little flaws that piss me off. While the music is clean and free of noise, the lead-ins almost always have some clicks, ticks and the occasional loud pop that cannot be removed running the machines this way. Some records will still have some minor ticks or even a slight crackle a few seconds into the first song on either side. With our dwell time set to 3 seconds, we'll get good sound, but we're not getting full dynamic range from our stampers. Center holes will be fairly well formed, but always have a small ring of material around the center hole, under the label or either one side of the record or the other. Records may be flat, but not completely flat. Stitching may be eliminated in most records, but there's always a record or two that has a small amount of stitching every 10-12 records.

Despite having years of machine operator experience and being a music and record fanatic since I was a toddler, I have never run a record press prior to working at the plant I'm at. As far as training, I had no frame of reference to compare how a record press should be run other than a nagging gut feeling that something is not right with the way things are being done that started after working at the plant for about three weeks. Not to mention the depression I would get when I would buy a new record made at another plant, pull it out of the sleeve and immediately say to myself, "how did they do this? How did they do that? How did they get that looking so good??"

Off an on these last two years, I have tried to experiment with settings in the hopes of finding what really works best to give us truly, the best looking and sounding records we can possibly make. Haven't had much luck, been reprimanded by the guy who trained me a few times and the other press operators look at me like I'm a bit because they're very content with running the machines the half-assed way they've been taught because it's easy and requires hardly any thought at all.

Recently, I have learned that by extending the dwell time on the press for roughly 6-7 seconds gives me much better sound quality, but I needed to balance the other time settings just right to get a record that wasn't warped, had stitching, was too thin or thick, had poorly formed center holes and still had noise. I have begun to learn to balance out my time settings so that the warm up and cool down times on the molds are almost the same (cool down might be less), use dwell to not only get optimum sound from the stampers, but use dwell in conjunction with the warm up time on the molds to get rid of a lot more crackles and ticks. The post dwell after cooling the molds down is still tricky because if I don't do it right, the records have stitching, are warped badly and/or the records look dark grey or flat black from too much heat instead of the nice dark shiny black they ought to be. An average time set up on my presses now looks more like this...

7.5-8.5 seconds of warm up time on the molds.
5.5-7.5 seconds of dwell
7.8-8.8 seconds of cool down time on the molds
5-9 seconds of dwell after moulds have cooled

As for pressure, I always press using the maximum 2,400 PSI on the press.

I'm sorry for a lengthy post, but I want to know if I'm going in the right direction with how I'm currently running the machines and if I'm overlooking something important or if there's something I never thought of. I'm getting better results and the owners of the company seem impressed and are also encouraging as they will look better to and get more business if I can make improvements. I still have trouble with getting settings just right on some jobs, but it's getting better. Any and all advise, help, tips, tricks, suggestions will be greatly appreciated. Thanks!

[boogievan]

Interesting post. Appreciate the candor, too.

When you mention, ' ...the lead-ins almost always have some clicks, ticks and the occasional loud pop that cannot be removed running the machines this way,' have you already played the mothers and confirmed that the surface noise in your pressings is not already on the stampers? I've never heard a stamper without these flaws, is why I ask, and a loud pop heard during mother-playback could preclude a pointless pressing session (using such a part).

Also curious about the 'full dynamic range' you cite not being realized from the stampers. How is this manifest? {Foe example, are you implying that the surface noise is so consistently prevalent that the noise-floor is now much higher than on the mothers, while the audio peaks from the groove modulation, which is intact, is, therefore, relatively less loud - even though the VU meters are swinging to their normal deflections during forte passages?}

Have you been able to get support from Viryl? Do they still offer training in Ontario? Might be worth a rail trip, if so.

Fwiw, the US's only vendor for lacquers is a record pressing veteran, in addition to making excellent stampers. He might be worth calling sometime - and maybe, if he doesn't already, he could make some nice parts for you.


- Boogie

[piaptk]

Reach out to Cash Carter. He is intimately familiar with Warmtones and does independent consulting for record pressing plants. He does it for a living and requires a reasonable rate for his time and expertise, but he is extremely knowledgeable. You may have to talk the pressing plant into investing a little money into it, but he WILL help you fix the problems you are having. Feel free to DM me for his contact info.

[Dogtemple]

I can’t help in any way, shape or form but it’s brilliant to read there is someone out there pressing records and wanting to improve the quality of their work despite the people around them. Hope you get it sorted.

[trailerparkjesus]

Appreciate this post. With all the new business it can make some resort to the "this is good enough" mentality just to turn and burn. I understand the pressure from clients can have an effect too. It's our responsibility being in the industry to ensure vinyl continues to be a viable and in demand format competing with audio quality of other formats. Meaning, "no shit leaves the shop"!

Good luck with your quest!

[boogievan]

How your experiments actually go will be your best guide, but, checking Nygaard's Physical Process of Cutting Gramophone Records, I saw that he states a typical pressing force of 1.500 Newtons per centimeter squared, which would be lower than "2.400 PSI', right? More like, 2175 PSI, according to the internets, which is right in between your preference and that of your boss, innit? Also, your chillers might be right, but do the plattens actually get down to ~86 degrees F (30 C) that way?

Also, fwiw, some typical scenarios of record defects found in Uncle Larry's Compendium, Basic Disc Mastering, which he dedicated to the memory of master cutter, Al Grundy, of Aquabogue, NY:

"TICKS + POPS: Press not heated to operating temperature, poor silvering of lacquer, impurities in vinyl

"RUMBLE: Improper sanding of stamper back; badly worn die

"ROAR IN LEAD IN GROOVE: Bad 'coining' or lead in groove has excessive depth"

As for 'stitching', check out item 5 on Mobineko's Vinyl Quality Standards webpage: https://www.mobineko.com/vinyl-quality-standards/

- Boogievan Eps

[PincheBolillo]

Unfortunately, we don't have access to the mother's as we don't do our own electroplating and get our stampers from outside sources. We have had some stampers made from damaged mothers before. In regards to clicks and ticks on the lead-ins as well as the full dynamic range I mentioned, the problem with the way everyone runs the presses is that while the molds may be warmed up to a good temperature, the hot puck doesn't get to sit in the hot closed press for very long. If we warm up our moulds for 8 seconds, that translates into we've warmed the molds up to about 250° fahrenheit. Then the dwell is set for 3 seconds, so that still forming record only gets to sit in the hot closed press for 3 seconds at 250°. If I set the dwell for 6-7 seconds, then I get all of the sound in those stampers because the material has more time to fill the ridges in the stamper properly. Depending on the music, some records will have a subtle but noticeable improvement in sound while others will make your jaw drop. We had one record we pressed a couple of weeks ago that had a lot of noise on the lead-ins and into the first few seconds of the first song on side A. Everyone kept the dwell at three seconds, but kept heating the moulds up more and more in an attempt to get rid of the noise.
Didn't work. I kept the moulds around 250° and let the record sit in the press for about 8-9 seconds and that killed the noise. I've been thinking about this after I posted my first message and I truly think some of the noise were getting is from the record not sitting in the hot closed press long enough. Kind of like cooking a steak in too short of a time period...it's cooked, but not completely all the way.

[PincheBolillo]

Still learning, experimenting and still asking questions. Now I can run the extruders correctly so were no longer pressing with vinyl that's either burned or not melted properly (and getting much nicer results), I'm also seeing the right balanced between mold temperatures and the length of time the record sits in the closed press makes the sound better, but also kills a lot more noise. What I'm still having trouble with is finding the right temperature to cool the record down to and the right length of time to let the record sit at that cool temperature before the press opens up. If I don't get stitching, then the record is badly warped or the record is a full dark grey from not enough cooling so the record isn't a nice dark shiny black. Is there an ideal range of temperatures to warm or cool the molds at?

[boogievan]

We'd love to hear from MossBoss on this thread. Until then, it makes sense that the same temp, but with longer dwell, could improve the filling between the turns of the spiral ridge. Checking around, it seems that your stampers might even tolerate a little more heating - up to around 290 degrees Fahrenheit.

As for dwell time, itself, fwiw, there's a video of a puck getting pressed, here: https://youtu.be/nA7QKPpF9rI. It shows the press fully having closed at 1:58 and then opening at 2:12. Of course, the cooling is happening during the second part of the overall dwell time, there. But the overall, full-closure is taking around 13.888... seconds. You do the maths, re: your chill-time needed to bring that hot pair of jaws down to 86 degrees F.

As for playing the two or more mothers' respective grooves (all the way through) for each album - ahead of pressing - does your plant not purchase access to the mothers when buying a 2-step set from the lab? It might be convenient to keep mothers stored at the lab before ordering sons, but doing so deprives your facility of the ability to ward off doomed pressings that shouldn't be undertaken due to (already-)noisy stampers. Obviously, when you've heard a quiet pressing made by a given pair, you thereby know that, at least, initially, the stampers had to have been good. But when you're vexed by a side, or both, that won't press well under any conditions, it would at least be nice to be able to point to the issue on the mother-capture in a DAW. Whereas QC'ing the mothers beforehand, though a time-consuming process in itself, saves time and money and grief (and keeps the proverbial 'waters' from becoming 'muddy' as to the cause). {I once had to reject over 20 stampers for a given side before a father was pulled gently enough from the lacquer not to tear the silver (which makes a 'once-around'-repeating scrape). So, as tedious as it was to QC 21 mothers for that one, A-side, it prevented the additional waste of time, energy, and money, from 20 pointless pressings, innit? I mean, we don't send a CD premaster to be burned to glass before painstakingly checking the data and auditioning the playback of a reference CD-R and then loading that back into the DAW in order to perform a null test against the program playing from the edit decision list with both of the load-back audio channels' waveform-polarity inverted. Since you can pre-vet mothers by playing them back (into a workstation), it would be my first line of defense against Sisyphal sessions near a boiler. ); }

- ∫øø©ˆ

[PincheBolillo]

I'll try warming the molds to 290° tonight and see what happens. It's only about 15° hotter, but that might help. After that, it's a question of making sure the records aren't warped and no stitching...and I don't waste 30 records in the process. . All of this stems from just wanting to do things in a thorough manner and not in the slam bang, half-ass way we were taught. I don't do well with "good enough".

[PincheBolillo]

Update:
Extruder temps are now 280/290/300 F and as of right now, 280/300/320 F with the die zone at 305. Records come out looking better, sound is better and this alone has gotten rid of some noise on lead ins. Mold temp is right about 250 F, cool time is 115 F. Records are flat, sound great, but still get stitching. Cycle time is 27 seconds so that's about what they want (2 records a minute). However, if I let the records sit in the press with a good, long period in the heat and then a really long time in the cold, I get records that are damn near perfect. Only problem is, is that the 47 second cycle time caused some criticism...along with the fact that the records had a very tiny warp that went away as soon as they hit the cooling plate. I was told that all I did was elongate what was already being done and achieved nothing. Thanks. If they want quickly produced records that are a little short on true quality, I can do it. But I'd rather take the extra time up front and produce something as close to top notch as possible and reduce the risk of having a lot of fails that have to be redone later and cost more time, more materials and more money. Gonna talk to the big bosses soon and see what they think as opposed to the guy who acts like he knows everything.

[PincheBolillo]

Is MossBoss on here frequently? I'd like to ask him a few questions if I can.

[boogievan]

I've not seen a new mossboss post here in a while.

Re: "...cool time is 115 F..."

Can you get the mould temp down to 86 degrees F before the press opens?

[PincheBolillo]

I've been able to get the mould temp down to about 95 at best. The Viryltech Warmtone allows me up to 20 seconds to cool the moulds down...and it made the worst stitching I've ever seen.

[Mary]

Thank you for sharing your challenges and solutions. I will be working in a brand new pressing plant that will be opening in a few months and reading your posts helps me understand even more the challenges ahead. I would love to help, but I don't have the knowledge yet! I will certainly want to keep in touch when I have more experience under my belt!

Keep up the good work!

[PincheBolillo]

Awesome!!! I've been doing this for two years now and while all the guys at my plant are happy to work in the framework of what they've been taught, I'm the nutty one who questions everything and experiments with different settings and spends portions of my weekends lost in thought over how to press records better. It makes you better at your job, but you're also looking out for the people who buy the records you press. At $20+ an Lp, I don't want some poorly pressed piece of shit. I want my money's worth and if us new guys can learn anything from the masters, this resurgence in vinyl will continue to grow and not die on the vine prematurely, like I'm afraid of. If you're new, here's my only advise for right now...

1. Learn everything you can about the machine you're running by whoever is training you and then get online and try to learn more.

2. Compare what your plant presses to what other plants can do. How do they do this? How did they do that? How did they get that looking so good? It helps to see areas in need of improvement. Start learning about the pressing plants around today and see what they can do and what others think about their work. I'm 40 years old and vinyl went pretty much "bye bye" when I was about 8 or 9. So I've accustomed to buying a lot of used records. Take note if the pressing plants from decades past and their quality of work. Some audiophiles are anal about getting a pressing of a certain album from one specific plant as opposed to another. Learn why and make notes.

3. Don't be afraid to ask questions. I've reached out to Gary Salstrom and Rick Hashimoto before and as far as advice, they talk like Obi Wan Kenobi (vague, general answers that don't make sense until you apply it and then the lightbulb pops on), but they've handed down to me so good tips. I talk to mastering engineer Kevin Grey sometimes. He's very cool and has lots of information not just on mastering, but pressing as well. He and Doug Sax have test pressings of Dark Side of the Moon that were made at RTI that apparently blow everything else out of the water!

4. The president of the plant I work at told me to experiment from time to time. That's awesome if the higher ups at your place tell you that as well. He told me, "if you make 10-20 records that are bad and go on the fail pile, I don't care. If it's an entire spindle, we're gonna have a different talk." Understood.

5. Believe it or not, ChatGPT or whatever it's called is actually pretty damn good at spitting out technical advise on record presses. I've learned a lot about the press I run just from that alone. But talking to humans is still the better option.

[Dub Bull]

Is the stitching happening randomly with a set of stampers that mostly doesn't cause this, or are certain stampers always causing it no matter what you tweak?

Stitching is attributed by Mobineko to stamper[/cut] issues ('horns that grab the vinyl (on release)...')
Whereas, Mossboss and others link this defect to 'release' issues, fwiw. {He hasn't posted since 2018. Hope all is well, Down Under. }
Here's what he wrote in a thread on non-fill that used the term, 'stitching'', also...

"...
1.Speed at the last 1/2-3/4 of an inch has to be as slow as possible so as to stop the press entrap{p]ing air
2.Vinyl to[o] hot out of the extruder gassing off
3.Hydrogen entrapment on the plates But that usually disa[p]pears after a few pressings about 20 odd sees it out of the plates
4.Second stage heating to[o] long prior to cooling stage
5.Dies where plates are mounted are a little loose on the guide pins and bushes
Important
6.Calcium build up on the cooling galleries of dies causing uneven heating cooling causing non fill
7.If there is a mix of regrind and virgin material no more than 20% of regrind should be used You are better off using straight reground or straight virgin material
Note: PVC compounds today as not as tolerating as they used to be due to missing additives like lead and cadmium which has been banned

8.Press has slack on its columns Doubtful on the smt but possible
Good check list Hey Start looking
Cheers"

...and check out this comment - though it pertains to SMT - at the bottom of the
thread on "Pressing defects", which includes an image of their 'stitching' issue:
https://www.lathetrolls.com/download/file.php?id=7652&mode=view

"...Those marks are easily fixed by changing your parameter for centre pin in (ram parameters) it[']s releasing to[o] fast. Checking your heater arm is sitting right helps too. It can happen if the arm is moving as the press opens. Just to be clear these marks are like little hair scratches right?"



- [He] is risen †

[darryl-rainbo]

Have you checked the tempature inside the cake when it comes out of the extruder.? What is the weight of the cake before pressing. By dwell time is that water delay? Have you tried to increase the weight to give more material to fill the outer groves more before cooling.
When this happens try to rotate the stampers 180 degrees on the side its happening on and does the issue follow the stamper or stay in the same area.

[tamachura]

we're also having some issue with smt stitching, have checked a ton of things i.e. hydraulic pressure, bolster plates being tight, new molds, old molds, mold temp, heating time and cooling time, water temp, water header pressure; stitching is moving around from side to side and random placement..

going to switch mounting rings today and see if theres any effect. our hamilton is running just fine..

seems like were unable to get a record without stitching even if its dished. has anyone else had luck recently? we're using tpc black and i was wondering if maybe they changed formula as wee ordered a gaylord and it came to us in bags. regrind hasnt worked either, mixture nor straight virgin or straight regrind. its not the stampers as we've tried with different sets and from different facilities.

[llary]

Is the stitching happening randomly with a set of stampers that mostly doesn't cause this, or are certain stampers always causing it no matter what you tweak?

Stitching is attributed by Mobineko to stamper[/cut] issues ('horns that grab the vinyl (on release)...')
Whereas, Mossboss and others link this defect to 'release' issues, fwiw. {He hasn't posted since 2018. Hope all is well, Down Under. }
Here's what he wrote in a thread on non-fill that used the term, '

Non fill and stitching are totally different things.

Stitching is generally caused by expansion and contraction of material in the grooves causing chunks of material to remain in the stamper. You can clearly see this damage under a low powered microscope. It CAN happen when you have some kind of depth variation or hooks/horns in the groove but this is not very common (I fear I have been somewhat misquoted above).

Stitching looks like a white stitched thread across patches of the disc, hence the name. It's not always audible but usually has an unpleasant distorted sound on playback. My first step to fix this would be to gradually reduce cooling time. Next would be to adjust mould heating time. It depends heavily on your PVC compound. If you are still having issues try rotating the stamper 90 degrees to see if the problem area moves. If it does then you may have some kind of blockage or leakage inside the mould. Bear in mind you can have a mould leakage and not every stamper/pressing will have issues.

Non fill is caused by failure to completely fill the grooves, almost always on the outside edge. It's not always visible but can be heard as a rough hissing sound or generally noisy pressing. Most likely culprit is an extrusion that's too cold. The extruded biscuit should look shiny and uniform on both sides with no cracks or bubbles and will allow you to leave a fingerprint on the surface. If your extrusion is good you would then want to experiment with hotter moulds.