antique at heart, contemporary in approach
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
antique at heart, contemporary in approach
[EDIT: Introduction by Steve E.--
It is my understanding that kd88 is referring to this article:
(dead version:
http://gadgets.qj.net/How-to-Pirate-a-Vinyl-Record/pg/49/aid/39381)
EDIT, December 2010, RESTORED LINKS:
http://mikesenese.com/DOIT/2010/07/how-vinyl-records-are-made-and-how-to-pirate-a-vinyl-record/
http://www.synthgear.com/2010/diy/how-to-pirate-a-vinyl-record/
What follows is one of the more remarkable things I've seen so far on our site. Check it out!! If I knew how, I'd move this up to the main forum.
kd88, by the way, is one of the three or four people whose experiments directly inspired me to start this site, though I'd lost track of him by the time I'd gotten it together. Really glad you are here!!--SE]
*****************
Hey, y'all...
I'm posting my preliminary (empirical) report on replicating audio discs with modern plastics.
If you're busy and want the short version:
-It DOES work.
-lacquer plates are not harmed by the process.
-the resulting product is a SINGLE SIDED, very robust plastic disc, useable in automatic changers, and capable of much more abuse than either a vinyl or shellac record.
Details:
-Products used in the test:
-Smooth-On Oomoo 30 (approx $25 for trial size)
-Smooth-On Task 4 (also $25 for trial)
-Cast Craft Mold Release ($8 for small spray bottle)
-12x12 shadow box ($30)
-silicone sealer
-plastic mixing containers
-stirring sticks
-paper towels for cleanup
Notes:
I used the shadow box to save me the carpentry of making a glass bottom "containment field" for the mold. I prepped the box by sealing the glass with silicone sealer.
I used a 10 inch dub plate that i had cut in December. It was a playable test of a spoken word recording. It was cut on the 6N, 120 LPI, 33 1/3rd, with a NOS sapphire, no heat. The B side was unplayable.
The Oomoo likes it warm, above 65 degrees F. I used space heaters to bring up the temp. Mixing the Oomoo is a challenge. It is quite viscous and the two colors take awhile to combine. It clings to the containers, and mixing it as recommended by pouring it from container to container is a bit of a mess. Not undoable. It turns out that it sticks to glass. My first attempt at pouring a mold was, therefore, a failure. But I was able to free the lacquer w/out damage (other than a thumbprint on the edge) and clean the cured silicone off the glass.
I had some mold release handy, so I used it. It worked. I got a successful mold.
The mold preserved the center hole, the cutter pin hole, and every detail of the lacquer...including my thumb print and every speck of dust. I did vacuum as much of the flotsam as I could before I poured.
The Task 4 seemed easier to mix. It has a long cure time and my pouring was plagued by tiny bubbles. I tried 'bushing them out', but only succeeded in pushing them around. There is a 16 hour(!) demold time.
End result:
The cast plastic disc relased from the mold beautifully. No need to drill any holes. The bubbles caused riotous patches of noise, and slight 'hills' in the mold caused valleys in the plastic which resulted in skipping. But despite these problems, which I attribute to my lack of experience with Task 4 casting, I am able to report that the result could be potentially excellent, high fidelity, and durable.
There is a guy shown on the Smooth-On site using these materials to copy (and sell) rare recordings. He claims these copies play beautifully on 'his Victrola'. So Steve, there you go! Give your handcranker a product of your own devising.
All my best...more to follow, including pics and sound files...
It is my understanding that kd88 is referring to this article:
(dead version:
http://gadgets.qj.net/How-to-Pirate-a-Vinyl-Record/pg/49/aid/39381)
EDIT, December 2010, RESTORED LINKS:
http://mikesenese.com/DOIT/2010/07/how-vinyl-records-are-made-and-how-to-pirate-a-vinyl-record/
http://www.synthgear.com/2010/diy/how-to-pirate-a-vinyl-record/
What follows is one of the more remarkable things I've seen so far on our site. Check it out!! If I knew how, I'd move this up to the main forum.
kd88, by the way, is one of the three or four people whose experiments directly inspired me to start this site, though I'd lost track of him by the time I'd gotten it together. Really glad you are here!!--SE]
*****************
Hey, y'all...
I'm posting my preliminary (empirical) report on replicating audio discs with modern plastics.
If you're busy and want the short version:
-It DOES work.
-lacquer plates are not harmed by the process.
-the resulting product is a SINGLE SIDED, very robust plastic disc, useable in automatic changers, and capable of much more abuse than either a vinyl or shellac record.
Details:
-Products used in the test:
-Smooth-On Oomoo 30 (approx $25 for trial size)
-Smooth-On Task 4 (also $25 for trial)
-Cast Craft Mold Release ($8 for small spray bottle)
-12x12 shadow box ($30)
-silicone sealer
-plastic mixing containers
-stirring sticks
-paper towels for cleanup
Notes:
I used the shadow box to save me the carpentry of making a glass bottom "containment field" for the mold. I prepped the box by sealing the glass with silicone sealer.
I used a 10 inch dub plate that i had cut in December. It was a playable test of a spoken word recording. It was cut on the 6N, 120 LPI, 33 1/3rd, with a NOS sapphire, no heat. The B side was unplayable.
The Oomoo likes it warm, above 65 degrees F. I used space heaters to bring up the temp. Mixing the Oomoo is a challenge. It is quite viscous and the two colors take awhile to combine. It clings to the containers, and mixing it as recommended by pouring it from container to container is a bit of a mess. Not undoable. It turns out that it sticks to glass. My first attempt at pouring a mold was, therefore, a failure. But I was able to free the lacquer w/out damage (other than a thumbprint on the edge) and clean the cured silicone off the glass.
I had some mold release handy, so I used it. It worked. I got a successful mold.
The mold preserved the center hole, the cutter pin hole, and every detail of the lacquer...including my thumb print and every speck of dust. I did vacuum as much of the flotsam as I could before I poured.
The Task 4 seemed easier to mix. It has a long cure time and my pouring was plagued by tiny bubbles. I tried 'bushing them out', but only succeeded in pushing them around. There is a 16 hour(!) demold time.
End result:
The cast plastic disc relased from the mold beautifully. No need to drill any holes. The bubbles caused riotous patches of noise, and slight 'hills' in the mold caused valleys in the plastic which resulted in skipping. But despite these problems, which I attribute to my lack of experience with Task 4 casting, I am able to report that the result could be potentially excellent, high fidelity, and durable.
There is a guy shown on the Smooth-On site using these materials to copy (and sell) rare recordings. He claims these copies play beautifully on 'his Victrola'. So Steve, there you go! Give your handcranker a product of your own devising.
All my best...more to follow, including pics and sound files...
Nice one brotha... I wonder if heating the task 4 a bit, would loosen it up, and alow it to flow better, without capturing the air. Maybe a bit of "PAM" spray on the glass to keep the oomoo from sticking.. A perfectly level work table, and the use of Master grade plates maybe the key...
I'm thinking of trying this out also.. If you figure out anymore tips, let us know...
Good Job..
I'm thinking of trying this out also.. If you figure out anymore tips, let us know...
Good Job..

Jay,
setting up another casting as I write this. (Spring break at University of Illinois!)
To bide the time, (all 16 hours...maybe not!) I'll promptly tackle your suggestions and comments.
-By all means, you should try this. A knowledge base should be developed.
-The mold release recommended by Smooth-On was not the one I used, but it worked very well. Smooth-On recommends other things, including vaseline cut with turpentine, waxes, etc., but if you want to copy a lacquer plate that is good on both sides, you won't want to mess up the glass side with goo. Even the mold release is dodgy. It leaves an impression on the Oomoo. (Natch.)
-A leveling system is essential. I did not really have a problem with that. I used a level and shims. (I had more of a problem with my own impatience!) If I get into this, I'll develop something better. (More convenient.) You have plenty of working time to get things level. Some tilting helps the flow go where you want it to.
-Smooth-On's 'safety first' page says that heating the Task 4 will release a poisonous gas. I was tempted but didn't try it.
-If by 'master grade plates' you mean as opposed to dub plates...well, these Apollo dubs sound very good. If I can get my copies to approach that quality, I'll be a happy camper. I think the dub is fine for this experiment. My whole problem is with the plastic and with processing it. A technique must be learned, evolved.
Now then, as for the attempt in progress, I've already detected that the bubble problem remains. The source of the trapped air is in the "A" part of the two part plastic. The bottle says shake vigorously, but doing that froths the stuff up. I tried de-frothing it by pouring it back and forth between containers (by now it might be clear to readers knowledgable about either art projects or chemistry, that I don't really have a clue what I'm doing). Uh. I poured it anyway.
And then, of course, my beginners luck ran out. I poured too much of it and it ran out of the form. So this time, I'll have some edge trimming to do. AND...
The bubbles are back.
I noticed, after strugging to get the plastic genie back in its bottle (or at least to stay in the mold), that the A part had settled down in its container and was clearer and bubble free. Next time (and supposedly, you get about 40 copies from one mold), I'm going to ignore the shake vigorously part.
I'm also about to go cruisin' for info on the web from other Task 4 users.
The Oomoo is really awesome, and trouble free.
Finally, I tried playing my record on a Califone School phono. Plays w/out skips. I'll upload a snippet and post the URL. Also, you might wanna see some pics.
And, BTW, many thanks for the words of encouragement.
setting up another casting as I write this. (Spring break at University of Illinois!)
To bide the time, (all 16 hours...maybe not!) I'll promptly tackle your suggestions and comments.
-By all means, you should try this. A knowledge base should be developed.
-The mold release recommended by Smooth-On was not the one I used, but it worked very well. Smooth-On recommends other things, including vaseline cut with turpentine, waxes, etc., but if you want to copy a lacquer plate that is good on both sides, you won't want to mess up the glass side with goo. Even the mold release is dodgy. It leaves an impression on the Oomoo. (Natch.)
-A leveling system is essential. I did not really have a problem with that. I used a level and shims. (I had more of a problem with my own impatience!) If I get into this, I'll develop something better. (More convenient.) You have plenty of working time to get things level. Some tilting helps the flow go where you want it to.
-Smooth-On's 'safety first' page says that heating the Task 4 will release a poisonous gas. I was tempted but didn't try it.
-If by 'master grade plates' you mean as opposed to dub plates...well, these Apollo dubs sound very good. If I can get my copies to approach that quality, I'll be a happy camper. I think the dub is fine for this experiment. My whole problem is with the plastic and with processing it. A technique must be learned, evolved.
Now then, as for the attempt in progress, I've already detected that the bubble problem remains. The source of the trapped air is in the "A" part of the two part plastic. The bottle says shake vigorously, but doing that froths the stuff up. I tried de-frothing it by pouring it back and forth between containers (by now it might be clear to readers knowledgable about either art projects or chemistry, that I don't really have a clue what I'm doing). Uh. I poured it anyway.
And then, of course, my beginners luck ran out. I poured too much of it and it ran out of the form. So this time, I'll have some edge trimming to do. AND...
The bubbles are back.
I noticed, after strugging to get the plastic genie back in its bottle (or at least to stay in the mold), that the A part had settled down in its container and was clearer and bubble free. Next time (and supposedly, you get about 40 copies from one mold), I'm going to ignore the shake vigorously part.
I'm also about to go cruisin' for info on the web from other Task 4 users.
The Oomoo is really awesome, and trouble free.
Finally, I tried playing my record on a Califone School phono. Plays w/out skips. I'll upload a snippet and post the URL. Also, you might wanna see some pics.
And, BTW, many thanks for the words of encouragement.
kay dee 88
"a warm tube and soft wax..."
"a warm tube and soft wax..."
Well, Dubs are just masters that have been rejected by QC, due to imperfections. The imperfections are fine for playback, but if you are going to press vinyl, a 1 side master is what you would send to the metal shop. The surface is perfectly smooth, with no blemishes. It might help to achieve a more true, and flat surface, with no hills, or pits.kd88 wrote: -If by 'master grade plates' you mean as opposed to dub plates...well, these Apollo dubs sound very good. If I can get my copies to approach that quality, I'll be a happy camper. I think the dub is fine for this experiment. My whole problem is with the plastic and with processing it. A technique must be learned, evolved.
True, it is a whole new art project, but with awesome rewards. Oneday, this maybe the only way to make a record.
Try to post some pictures of your process, it will make the thread look cool..
I wonder if you made one of these "BLANK", if you could cut into them with a diamond stylus?..
oh, and more importantly.
Where did you find the supplies?..
All readers:
here's the URL to a sound clip from my first attempt.
https://netfiles.uiuc.edu/beck2/shared/task_4_plate_1_clip.mp3
2nd attempt was pretty much botched, but I did get a leveler copy by taking pains to flatten the mold. Still many bubbles. I have now figured out that moisture is the problem. Task 4 absorbs moisture and forms bubbles as a reaction.
I will take photos of my 3rd attempt.
here's the URL to a sound clip from my first attempt.
https://netfiles.uiuc.edu/beck2/shared/task_4_plate_1_clip.mp3
2nd attempt was pretty much botched, but I did get a leveler copy by taking pains to flatten the mold. Still many bubbles. I have now figured out that moisture is the problem. Task 4 absorbs moisture and forms bubbles as a reaction.
I will take photos of my 3rd attempt.
kay dee 88
"a warm tube and soft wax..."
"a warm tube and soft wax..."
task 4, take three, with photos and audio
Well, I've got a handle on how this works now. Moisture control is one key, meticulousness in every other detail another. I am not quite there yet, and my mold is very funky now. But I get the idea.
The photos are at:
https://netfiles.uiuc.edu/beck2/shared/plastic_plating_process/
The photos are 4 meg each, fairly high rez jpegs. You'll need broadband and some patience.
A sound file of attempt 3 is:
https://netfiles.uiuc.edu/beck2/shared/task_4_plate_3_clip.mp3
Same exact section of the plate as before, but a different plate (:)), and this time the magnetic cartridge would track it. So it's a Sure M-91-ED, NAB EQ (which is what the record was cut with), and other than that no processing.
Next: making a plate of a "78". I'll make something Busy Bee sized, since that's all the Oomoo I've got left. The goal is to make something Brunswick worthy.
Input/reactions appreciated.
But my basic feeling about this is that it is really another 'art project'/ bricolage item...will not replace the tried and true metal plating process honed over many years of r & d.
Edit: link corrected by admin--SE
The photos are at:
https://netfiles.uiuc.edu/beck2/shared/plastic_plating_process/
The photos are 4 meg each, fairly high rez jpegs. You'll need broadband and some patience.
A sound file of attempt 3 is:
https://netfiles.uiuc.edu/beck2/shared/task_4_plate_3_clip.mp3
Same exact section of the plate as before, but a different plate (:)), and this time the magnetic cartridge would track it. So it's a Sure M-91-ED, NAB EQ (which is what the record was cut with), and other than that no processing.
Next: making a plate of a "78". I'll make something Busy Bee sized, since that's all the Oomoo I've got left. The goal is to make something Brunswick worthy.
Input/reactions appreciated.
But my basic feeling about this is that it is really another 'art project'/ bricolage item...will not replace the tried and true metal plating process honed over many years of r & d.
Edit: link corrected by admin--SE
kay dee 88
"a warm tube and soft wax..."
"a warm tube and soft wax..."
- Scheckywhite
- Posts: 16
- Joined: Wed Oct 03, 2007 7:52 pm
Man I tried this method about 3 months ago and blew a whole pile of money-
Seems you need to be ridiculously meticulous and cautionary with
every single mould you make and cast you pour.
I made one 7'' from it, bubbles galore and it skips more than a slutty schoolgirl,
however due to the nature of task 4 I found that you only get limited number of plays as the sound degrades very fast.
Or at least it did for me...
Well done to those who got it right though!
Seems you need to be ridiculously meticulous and cautionary with
every single mould you make and cast you pour.
I made one 7'' from it, bubbles galore and it skips more than a slutty schoolgirl,
however due to the nature of task 4 I found that you only get limited number of plays as the sound degrades very fast.
Or at least it did for me...
Well done to those who got it right though!
- ArchaicRecords
- Posts: 56
- Joined: Fri Mar 03, 2006 10:36 pm
- Location: USA: Lexington, KY
copying record with Smooth-On plastic molding
This video shows how a large double-sided coin is copied:
http://www.smooth-on.com/index.php?cPath=2_1113_1136
Would it be possible to use this same method for copying a record, extending the molding process out to accomodate a 7", 10", or 12" record?
Is it necessary to use "Task 4" plastic for the final copy of a record, or would it be possible to use the same plastic used for the copy of the coin shown in the video? Especially if the purpose is to make a novelty record. The method used for the coin could be applied to making a 2-sided record, if it is possible to use the same plastic as shown in the video example. What is special about using "Task 4"? Have you used any of the other plastics?
http://www.smooth-on.com/index.php?cPath=2_1113_1136
Would it be possible to use this same method for copying a record, extending the molding process out to accomodate a 7", 10", or 12" record?
Is it necessary to use "Task 4" plastic for the final copy of a record, or would it be possible to use the same plastic used for the copy of the coin shown in the video? Especially if the purpose is to make a novelty record. The method used for the coin could be applied to making a 2-sided record, if it is possible to use the same plastic as shown in the video example. What is special about using "Task 4"? Have you used any of the other plastics?
- alienmanstk
- Posts: 36
- Joined: Tue Aug 19, 2008 12:04 pm
Re: copying record with Smooth-On plastic molding
I think the nature of task 4, found only get limited number of plays as the sound degrades very fast.... so it is so lucky to those who got is right..ArchaicRecords wrote:This video shows how a large double-sided coin is copied:
http://www.smooth-on.com/index.php?cPath=2_1113_1136
Would it be possible to use this same method for copying a record, extending the molding process out to accomodate a 7", 10", or 12" record?
Is it necessary to use "Task 4" plastic for the final copy of a record, or would it be possible to use the same plastic used for the copy of the coin shown in the video? Especially if the purpose is to make a novelty record. The method used for the coin could be applied to making a 2-sided record, if it is possible to use the same plastic as shown in the video example. What is special about using "Task 4"? Have you used any of the other plastics?
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- oliver8bit
- Posts: 17
- Joined: Wed Apr 23, 2008 2:50 pm
okay i did alot of research a year ago on this stuff. unfortunately it was all saved on my laptop and got stolen but i still remember most things.,
Task 4 has a low enough shrink rate (.0035 in/in) that it wont make the playback skip when playing at 78rpm, which is what is used in the example and is the highest rate for a analog record. you can make concessions to that property but probably only if you're going for 33 1/3 rpm playback. i'd say 45 is still too fast to neglect the shrink rate.
Task 4 also dries to a shore hardness of 83D, which is really quite hard and probably a bit harder than most commercial records (certainly 70s/80s reprints). id say casting a record in anything from 70-80D would yeild a large number of playbacks (several dozen) before disintegration, the stronger the better, with 83 being the sweet spot. concern has been raised about dupe records wearing down quickly but if you play a commercial record repeatedly it will wear down so what is the big deal?
only problem with Task 4 is that it has a 16 hours demold time, meaning you need to leave it in the mold for that long. there are plenty of urethanes available that cut this down to as low as 5-10 mins, leaving the door open for semi-mass production.
using this kind of material a 7" can be duped for material cost of under $1, a 12" at a little over $1. the silicone molds are well worth the investment and can be cast into hundreds of times before decreasing quality.
if anyone knows any sculpture/casting experts and would like to quiz them on some other materials to try please post any suggestions here. i experimented with fiberglass resin (home depot, super cheap, clear!) but it is very difficult to cure. i want to dry dental plaster or dye stone but the material has to be completely smooth on the surface to work. no air bubbles, bumps, textures, obv
Task 4 has a low enough shrink rate (.0035 in/in) that it wont make the playback skip when playing at 78rpm, which is what is used in the example and is the highest rate for a analog record. you can make concessions to that property but probably only if you're going for 33 1/3 rpm playback. i'd say 45 is still too fast to neglect the shrink rate.
Task 4 also dries to a shore hardness of 83D, which is really quite hard and probably a bit harder than most commercial records (certainly 70s/80s reprints). id say casting a record in anything from 70-80D would yeild a large number of playbacks (several dozen) before disintegration, the stronger the better, with 83 being the sweet spot. concern has been raised about dupe records wearing down quickly but if you play a commercial record repeatedly it will wear down so what is the big deal?
only problem with Task 4 is that it has a 16 hours demold time, meaning you need to leave it in the mold for that long. there are plenty of urethanes available that cut this down to as low as 5-10 mins, leaving the door open for semi-mass production.
using this kind of material a 7" can be duped for material cost of under $1, a 12" at a little over $1. the silicone molds are well worth the investment and can be cast into hundreds of times before decreasing quality.
if anyone knows any sculpture/casting experts and would like to quiz them on some other materials to try please post any suggestions here. i experimented with fiberglass resin (home depot, super cheap, clear!) but it is very difficult to cure. i want to dry dental plaster or dye stone but the material has to be completely smooth on the surface to work. no air bubbles, bumps, textures, obv
Re: copying record with Smooth-On plastic molding
ArchaicRecords wrote:This video shows how a large double-sided coin is copied:
http://www.smooth-on.com/index.php?cPath=2_1113_1136
Would it be possible to use this same method for copying a record, extending the molding process out to accomodate a 7", 10", or 12" record?
Is it necessary to use "Task 4" plastic for the final copy of a record, or would it be possible to use the same plastic used for the copy of the coin shown in the video? Especially if the purpose is to make a novelty record. The method used for the coin could be applied to making a 2-sided record, if it is possible to use the same plastic as shown in the video example. What is special about using "Task 4"? Have you used any of the other plastics?

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- oliver8bit
- Posts: 17
- Joined: Wed Apr 23, 2008 2:50 pm
- ArchaicRecords
- Posts: 56
- Joined: Fri Mar 03, 2006 10:36 pm
- Location: USA: Lexington, KY
It's still online but looks like the URL has changed:
http://iphone.qj.net/ArticleDetail.php?aid=39381
http://iphone.qj.net/ArticleDetail.php?aid=39381
archaicrecords.com
well thanks for the help now i know..oliver8bit wrote:okay i did alot of research a year ago on this stuff. unfortunately it was all saved on my laptop and got stolen but i still remember most things.,
Task 4 has a low enough shrink rate (.0035 in/in) that it wont make the playback skip when playing at 78rpm, which is what is used in the example and is the highest rate for a analog record. you can make concessions to that property but probably only if you're going for 33 1/3 rpm playback. i'd say 45 is still too fast to neglect the shrink rate.
Task 4 also dries to a shore hardness of 83D, which is really quite hard and probably a bit harder than most commercial records (certainly 70s/80s reprints). id say casting a record in anything from 70-80D would yeild a large number of playbacks (several dozen) before disintegration, the stronger the better, with 83 being the sweet spot. concern has been raised about dupe records wearing down quickly but if you play a commercial record repeatedly it will wear down so what is the big deal?
only problem with Task 4 is that it has a 16 hours demold time, meaning you need to leave it in the mold for that long. there are plenty of urethanes available that cut this down to as low as 5-10 mins, leaving the door open for semi-mass production.
using this kind of material a 7" can be duped for material cost of under $1, a 12" at a little over $1. the silicone molds are well worth the investment and can be cast into hundreds of times before decreasing quality.
if anyone knows any sculpture/casting experts and would like to quiz them on some other materials to try please post any suggestions here. i experimented with fiberglass resin (home depot, super cheap, clear!) but it is very difficult to cure. i want to dry dental plaster or dye stone but the material has to be completely smooth on the surface to work. no air bubbles, bumps, textures, obv
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I've tried this a couple times, and had a big problem with bubbles as well.
However, I do have one thing that might help:
Rather than using a shadowbox, or building glass bottom box, etc, go to a thrift store and buy a rounnd, plastic holiday cookie/serving tray that corresponds to a little larger than the size of your record. Not only do you save the time/money of building something, but you also save the cost of the mold plastic by using the minimum and not having the square corners on a round mold.
However, I do have one thing that might help:
Rather than using a shadowbox, or building glass bottom box, etc, go to a thrift store and buy a rounnd, plastic holiday cookie/serving tray that corresponds to a little larger than the size of your record. Not only do you save the time/money of building something, but you also save the cost of the mold plastic by using the minimum and not having the square corners on a round mold.
I did this with a commercial 78 about 20 years ago using products of the Castolite Corp. in Illinois. I'm not familiar with the Task/Oomoo products or their consistency, but I used some of Castolite's rubber moulding compound and then cast the "dupe" in clear Castolite. I didn't have problems with bubbles by literally 'painting' the rubber compound into the grooves with a fine camel hair paintbrush. Got this from Eldridge Johnson "painting" the graphite into the grooves of his master disks as part of his early electroforming process to make wax disks conductive. (This was before his use of sputtering like Edison.) This really got the material into the grooves and worked out any bubbles, then I just poured more of the mold compound on to make the thicker "backing" in order to make the mould stable enough to remove from the record and turn over to pour the cast copy. I think I did use a plastic or tin service tray with about a 1/4" lip just larger than the disk as I remember the mould being round.
When casting the copy, you do the same - "paint" the casting compound over the grooves of the mould to make sure everything is covered consistently and to prevent air bubbles. Anyway, the result was playable, durable and served the purpose.
When casting the copy, you do the same - "paint" the casting compound over the grooves of the mould to make sure everything is covered consistently and to prevent air bubbles. Anyway, the result was playable, durable and served the purpose.