Has anyone ever tried to flatten a warped LP with two pieces of glass?

Discussion in 'Audio Hardware' started by SteveSDCA, Apr 12, 2006.

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  1. SteveSDCA

    SteveSDCA Forum Resident Thread Starter

    Location:
    San Diego
    I was talking to the guy that owns an LP store I go to a lot. We were talking about how "theoretically" you could take two 1/4 inch pieces of glass and sandwich a warped LP in between and just leave it in the sun until it becomes flat. I guess you would have to leave the LP in between the glass for an hour to let it cool. Has anyone ever tried this "trick"?
     
  2. coopmv

    coopmv Newton 1/30/2001 - 8/31/2011

    Location:
    CT, USA
    I read somewhere there is some machine that can be purchased for home use that will do just that, though the machine will set you back a few grands.
     
  3. SteveSDCA

    SteveSDCA Forum Resident Thread Starter

    Location:
    San Diego

    I read about the machine. I'll wait until it goes down to $500? if it ever does!
     
  4. ivan_wemple

    ivan_wemple Forum Resident

    I've tried the glass in the sun thing. It simply did not work.
     
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  5. Lord Hawthorne

    Lord Hawthorne Currently Untitled

    Location:
    Portland, Oregon
    Me too, about 30 times, all with awful results. The record flattened, but expanded outward in a most uneven fashion, untrackable even if the groove had maintained its angle-cut integrity, which it didn't. It collapsed.
     
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  6. Rachael Bee

    Rachael Bee Miembra muy loca

    I watched some guys do this once but they used an oven on warm for about 15 minutes and then took it out to cool. They took the glass out on the porch and poured water on the glass to speed up the cooling. I know they played the record about an hour later. I really don't recall how well it played. It's not like this was recently.
     
  7. coopmv

    coopmv Newton 1/30/2001 - 8/31/2011

    Location:
    CT, USA
    I am afraid due to the somewhat limited demand of this LP-flattening machine, its unit price may never drop below $1000.
     
  8. Gregory Earl

    Gregory Earl Forum Resident

    Location:
    Kantucki
    I've tried the glass thing a couple of times. First time it seemed to work pretty well. Second time it cracked the outer edge of the album. I'll never do it again.

    The Periphery Ring is the best device I have ever used to eliminate warped records.
     
  9. CardinalFang

    CardinalFang New Member

    Location:
    ....
  10. Gregory Earl

    Gregory Earl Forum Resident

    Location:
    Kantucki
    He may work for one side of a record but wouldn't do much for the other side.
     
  11. bangsezmax

    bangsezmax Forum Resident

    Location:
    Durham, NC, USA
    I've done it successfully. I think the real trick is to monitor it closely -- in full sun, depending on the temperature, it will not take long to get the vinyl pliant, and you should flip it to keep the heating even on both sides -- and let it cool out of the sun for a long time before removing it. I would also recommend doing it on a ~70F day as opposed to an 80F+ one.
     
  12. Ski Bum

    Ski Bum Happy Audiophile

    Location:
    Long Island, NY
    Most tweaks are harmless if they don't work. This one scares me. You should carefully read the warnings at the bottom of the page. 6-1/2 pounds is going to cripple any suspended TT, and may be considered mighty unfriendly by a lot of TT bearings and motors. Why not just use a clamp?
     
  13. Tony Plachy

    Tony Plachy Forum Resident

    Location:
    Pleasantville, NY
    I agree, I have not up graded my TNT-HR yet to use the ring, but I have seen it demonstrated and it really works. I wonder if you left the clamp and ring on the record on the TT if the warp would flatten out over time?
     
  14. Leppo

    Leppo Forum Librarian

    Location:
    Off Broadway
  15. pbonniwe

    pbonniwe New Member

    Location:
    Huestown
    Long ago, loaned out, and lost to time, I had success with the following approach:

    I originally got the notion for the process from reading about stress relieving of steel. My device was two aluminum turntable platters (at least one was a Thorens), with the spindles pushed out. The record was sandwiched btween thin cork sheets between the platter metal. The center was cut out of the cork sheet where record label would be. The largest grade 8 bolt that would fit through the center was used as a clamp screw. Since this was back when I had access to a machine shop, I had "clamp plates" made that distributed the clamp action over more of the aluminum surface. Plus, depending on the severity of the warp, I might lightly clamp the edges with the vise-grip c-clamp. With a record in one of those Mo-Fi sleves and clamped inside, I would wrap the whole thing in a wool army blanket and set it on a big cookie sheet in the oven.

    I had experimented to find the absolute lowest possible heat setting for the oven (gas at one time, electric at another), and that is what I would use. A meat thermometer indicated 140-150 F. The record "charge" was loaded into the cold oven, and the oven turned on that lowest setting. It was left undisturbed for 2 hours max (1 hours seemed not long enough), after which the oven heat was turned off, and the "charge" left in the oven until stone cold. The total cycle time was 6-8 hours.

    Im my opinion, the other methods create uncontrolled thermal gradients through the record section, this causes differential thermal expansion, this causes dimensional strain/deformation, and consequent residual stress on cooling, which resolves itself geometrically as warpage. Philosophically, my approach intended to minimize the potential for uneven heating and cooling and consequent residual stress after the material has been stress relieved and relaxed by the elevated temrperature treatment. The slow heat up and cool down and the insulation work to this end. The physical effects of putting the glass/record assembley in the sun and water quenching are fundamentally counter to this approach.
     
  16. Lord Hawthorne

    Lord Hawthorne Currently Untitled

    Location:
    Portland, Oregon
    The only method I have found to flatten a warped record without any further damage is to put something heavy on it for several months.
     
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  17. luckett

    luckett Forum Resident

    Years ago, a friend of mine tried to flatten a warped record by putting it in the oven.....you can guess what happened to his record....
     
  18. Nad 214

    Nad 214 Forum Resident

    Location:
    Ohio
    From all I've read it's not so much heat as it is time to flatten. I had excellent results with a Beatles Ep that was unplayable beleive me I tried to play it and ruined a new stylus, anyway I put it on top of an old 20 inch tv the type with the plastic case let it sit a couple of days with a couple of heavy books, and poof warp was gone. Now i know this may not work with an Lp but my point is that the longer you let it sit with enough weight on it should work. The oven or sun thing scares me. I was thinking of trying to fix a MONO Sgt Pepper I got buy putting it on a heavy cast iron stove we use at work as the one side stays warm but not to warm as to burn your hand, I know I let my hand sit there for 10 minutes and it was hot but not to the point that my hand hurt. I'll let you know my results if I try it.
     
  19. pbonniwe

    pbonniwe New Member

    Location:
    Huestown
    I think the active mechanism is thermal activation of material flow, at the molecular level. Increasing temperature merely acts to speed up the flow, under stress (and diffusion too). As with all things technical, the deville is in the details, and temperature control is essential for a desirable effect.
     
  20. Robert Lan

    Robert Lan Active Member

    Location:
    Taipei
    I agree. Here's an easy trick that has worked every single time for me: (i) put your warped LP in a plastic sleeve (to protect it from dust, etc.); (ii) place the LP on a hard/flat surface (large marble tile is perfect); (iii) put a 2 cubic feet (~ 18" X 15" X 12.5") box filled with books (newspapers, magazines, etc.) on top of LP; (iv) leave alone for a couple weeks. Your LP will come out (near-)perfect.
     
  21. pbonniwe

    pbonniwe New Member

    Location:
    Huestown
    Too bad someone from Classic record won't post in this thread. I'm sure someone there has by now figured out a good technique.
     
  22. coopmv

    coopmv Newton 1/30/2001 - 8/31/2011

    Location:
    CT, USA
    I have not seen many badly warped records among the 3000+ LPs in classical recordings I have. For one, they are 98% European imports, which usually have much better quality than American-made vinyl.
     
  23. Passerby

    Passerby New Member

    Worked fine for me. Saved my beloved Bruno Walter's Parsifal.
    I did my best not to over cook things and to heat the record evenly.
    I've only done this once so I don't know if I was just lucky.

    This as far as I remember is what I did (about a month ago now).

    I put my warped album between two sheets of glass.
    The sandwich was placed flat on the floor before a window in the sunshine on a moderately warm sunny day.
    I put some weights (4 [or was it 8?] bean tins) on the glass, being careful that they did not to cast shadows onto the Vinyl.

    After about ten minutes (I could feel the glass above the dark Vinyl was a little warmer than the surrounding glass) and before I could see any flattening I turned the sandwich over.

    In another ten minutes or so I saw that the record was beginning to flatten,
    so I closed the curtains, added some extra weights (books and tins) and left to cool.

    The record is very nearly totally flat now I can no longer hear any distortion.
     
  24. Antares

    Antares Forum Resident

    Location:
    Flanders
    I must have done about a dozen in recent years (using just 1/4" thick smoked glass, some clamps and solar power) and I'm happy with the results I got. Not always 100% but if you can get a 3 mm edge warp down to 1 mm, it makes a big difference. Only had one mishap where the record played with a whooshing sound afterwards. It probably got too hot for that particular vinyl formulation, so I prefer doing multiple sessions rather than risk overheating now. The records must be very clean too. The last one I did is a recent German pressing of Joni Mitchell - Blue, which was lightly dished and is perfectly flat now. Just need to take your time and not try to rush a result.
     
  25. MacGyver

    MacGyver Forum Resident

    Location:
    IRRIGON, OR. U.S.

    FURUTECH "Disc Flattener"

    http://www.furutech.com/2013/02/02/1790/
     
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