Tips for De-Warping Records?

Subject: Tips for De-Warping Records?
From: cnd
Date: 02 Feb 22 - 08:46 PM

Earlier this summer some friends kindly bought me some vinyl records, but then subsequently left them in the trunk of their car for several weeks. Being in a car's trunk in the South during the summer is, let's just say, not ideal record storage, leading to several of the records becoming severely warped.

I tried setting several large books and weights on top of them for an extended period of time (we're talking about a month or more, here) to no avail. I also tried the Wiki-How oven trick; buy two panes of glass, set the record between them with the oven at 175, take them out after 3 minutes, and then immediately press the record between the sheets of glass with something heavy while they're cooling. Still no dice here.

So do any of you have tips? Is 175 too cool? Should I wait longer than 3 minutes? I have several throw-away records to test on, so I'm willing to try a few different methods here.

Subject: RE: Tips for De-Warping Records?
From: GUEST,Phil d'Conch
Date: 02 Feb 22 - 09:01 PM

RE melt temps: Unfortunately there were any number of company 'recipes' for the vinyl. What you learn on one record will apply to the next only by chance.

In my experience the finer, brighter detail in the groove bottom is already gone, melted as it were. Nobody I know ever found a way to put it back the way it was.

Subject: RE: Tips for De-Warping Records?
From: GUEST,Ray
Date: 03 Feb 22 - 03:58 AM

Making plant pots out of vinyl records became quite popular in the 1960s and it involved boiling water.

Subject: RE: Tips for De-Warping Records?
From: John MacKenzie
Date: 03 Feb 22 - 04:12 AM

I haven't tried this method, but believe it works. Place the record between two sheets of glass, place in the sun, with a decent weight on top, and let the sun undo what it did before.

Subject: RE: Tips for De-Warping Records?
From: BobL
Date: 03 Feb 22 - 04:26 AM

If all else fails and you have enough life expectancy, digitize them and keep an eye on developments in sound-processing software. Compensation for warping (in straightforward cases at least) should technically be possible, and might even be with us already.

Subject: RE: Tips for De-Warping Records?
From: gillymor
Date: 03 Feb 22 - 04:41 AM

I've used the glass trick and it flattened out an LP to where it was playable but it was at the expense of some audio quality. It was the Dick Gaughan album "No More Forever" and it became one of my most played for a long time though it was a scratchy, bumpy ride,

Subject: RE: Tips for De-Warping Records?
From: cnd
Date: 03 Feb 22 - 08:16 AM

Thanks for all the suggestions. I may try the sun trick you suggested, John MacKenzie, when it's warm again. For now I think I'll try it in the oven at a low temp, and maybe that will help.

I'm aware that a significant loss in play quality is not only possible, but likely, however at the moment a few of them are so warped that the record arm cannot stay against the record -- the warp is so steep that it launches the needle airborne and skips significant portions of the first few tracks on the record.

BobL, there are a few neat things that come to mind with that. I've read a while ago (2015 or so) that technology was developed to digitize records just using a precision camera for cases where the original disk is rendered unplayable by conventional means, however that's likely still very expensive. There are, of course, audio engineers who could correct the tracks, but that is also prohibitively expensive, especially for some albums I'm listening to for fun more than anything else. Finally, I could record them myself and use a program to fix them, but in my experience, any changes I've attempted to make using Audacity have done more harm than good.

Gillymor, any chance you remember the temp and time you used?

Subject: RE: Tips for De-Warping Records?
From: gillymor
Date: 03 Feb 22 - 08:26 AM

That was a long time ago but I recall I took a couple of picture frames apart for the glass and placed it all out it the hot Florida sun for just a few minutes. I would approach it with caution and check it frequently. You might even try leaving it inside by a window if you get a sunny winter day.

Subject: RE: Tips for De-Warping Records?
From: GUEST,Grishka
Date: 03 Feb 22 - 01:38 PM

Nowadays, vinyl records can be digitized contactlessly with a laser scanner, however warped (- well, I'm not sure in the case of those plant pots). With really valuable recordings, e.g. of rare ethnic music, this is the method to choose. As observed by the above posters, any attempt to flatten a record will reduce the audio quality even more.

Subject: RE: Tips for De-Warping Records?
From: Felipa
Date: 03 Feb 22 - 02:29 PM

that's really interesting Grishka. Can you give more info. on the technology required?

Subject: RE: Tips for De-Warping Records?
From: robomatic
Date: 03 Feb 22 - 03:15 PM

Laser turntables have been around for over ten years now, but I do not know if there is one that can track a record groove in three dimensions to recover musical data. There must be a combination of equipment and techniques to do as you require, because there will be historical recordings that are misshapen and broken. The question is who can do it and what will it cost. You might contact some organizations that would need the service, i.e. museums or even posh libraries.
Sorry for my off the top of my head response without hard info.

Subject: RE: Tips for De-Warping Records?
From: GUEST,Grishka
Date: 04 Feb 22 - 08:24 AM

Felipa: robomatic nailed it. Ethnomusicologists and linguists may be the ones to ask, they often deal with unique old recordings. Since you don't mention the latter quality of your purchase, and in fact have "ironed" the records already, you are not likely to spend the money necessary.

Subject: RE: Tips for De-Warping Records?
From: Felipa
Date: 04 Feb 22 - 03:26 PM

Griska, if the laser reader you refer to is connected to a turntable, it probably would not be able to deal well with warped records.

Subject: RE: Tips for De-Warping Records?
From: Bonzo3legs
Date: 04 Feb 22 - 03:47 PM

Buy the CD!

Subject: RE: Tips for De-Warping Records?
From: cnd
Date: 05 Feb 22 - 08:19 AM

Thanks for the suggestions, but the records frankly aren't really worth paying the kind of money an institution would want to graphically convert. Two of them are just stock-in-trade bluegrass records, and though one is available online, the other isn't. The remaining few are gospel groups which, while they may have some local interest, likely won't garner much.