hobbyists's views for hobbyists
Is There An Easy Way To Correct Warped Records?

Page first published on June 29, 2009


There are various methods
for correcting warped records.

1. Putting the LP between two glass plates and put this stack in the oven.

This procedure has to be executed with care. Chances are that it will not help, but only melt part of the groove in the warped section or the entire record. I neever use this method.

2. Using a special machine that brings the vinyl gradually to a set temperature and then cools it down overnight.
The machine is costly and generally effective. Very serious and complicated warps can not be fixed.

3. Making use of time.
This is in essence the less costly and generally a very effective method, but only then if you are not in a hurry.

Use Time and Patience to Prevent and Fix Warps in LPs.

In the olden days of thick flat mono records, warps were brought about through mishandling a record by the owner.
In the 1970's less vinyl was used. Warps were easily made and generally already made in the factory just after the record had been pressed.

The employee in the pressing plant would lift the freshly pressed record with the index fingers of left and right hand off the matrix before it was sufficiently cooled down. This was especially the case when thousands of records had to be pressed in a short time. On those records there were generally two warps. In modern factories the pressing process is mostly automated.

Those warps will generally not be corrected or you will have difficulty correcting them because vinyl has a memory. However most warps you will encounter are the result of temporarily exposing a record to a heat source, be it the central heating or the sunshine.

If the room temperature is rather high and the records are laying about or not stored with care, one or more light warps can be the result. Warps can gradually manifest themselves over time when records are packed in a box with too much room.

It is difficult to correct warps. The method with glass plates does seldom work to satisfaction; in my experience it never works! The main reason is that the vinyl is clamped in between the heavy glass plates and a gradual flattening over time will be obstructed by the heavy glass plates which do not allow the vinyl to move/expand/stretch/relax.

The only effective method to correct warps is to use a special component like Clearaudio's Vinyl Doctor or a similar device. The vinyl record is put into the device, slowly heated to a safe temperature and then it is cooled down over several hours or even overnight. But such a machine is rather costly and only pays off if you have too many warped records. And in some cases it does not have the desired effect.

This is how you can do it.
Light warps of thin records can generally be corrected on the turntable during play using a Peripheral record ring. But after the record has been played, the warp just stays. To correct more severe warps in heavy records a heavier ring must be used. But then correction is not always possible - this is so in my experience as I have both a light weight peripheral ring and a heavy metal ring as well.
So what to do with warped records? First let's have a look at those in a box. Examine what sort of warp you are dealing with. Is there a curve at the periphery at one spot caused by sagging or does the record have the shape of a dish? First of all get rid of the soft plastic foam. Plastic foam was maybe right at the time of production, but after so many years it certainly has deteriorated and has lost its elasticity and consistency. If there is a cardboard filler, it should be sturdy and completely flat. If it is not, throw it away as well or keep it but outside the box.

Now measure the size of the compartment: height and width.

Cut out squares of thick cardboard and make sure that they can be placed into the box easily.
Cut off one small corner so you will be able to take out the cardboard filler easily if necessary.
Use the cardboard sheet as a replacement of whatever filler there was in the box before. See to it that the cardboard is flat and sturdy. You can choose the thickness in relation to the space (room) you want to fill up. In the picture at right you see ordinary cardboard. If you want you can buy a nicer material in the art supply shop. But it should always be completely flat and have no tendency to bend easily.
Put the records in the box. See to it that there is no room left for sagging.
If there is room left it is necessary to put an extra square sheet of cardboard on top of the records before adding the document (book or inlay). Hopefully the documents have the size of a record and are not the smaller booklets often provided by EMI in Great Britain. Then close the box and store it vertically. This will prevent warping and will help correcting light warps over time. As a matter of fact in this way time is your aid.

So if you encounter a box containing warped or concave records, do not throw these away. Just fill up the empty space and make sure that there is no room left when the box is closed! A tight fit is necessary. Store the box on the shelf so that it is supported on both sides by other boxes and records. It is better to store records and boxes rather tightly instead of loose. You may discover that after a couple of weeks or a month the records will have flattened.

It goes without saying that the records should be cleaned or at least dusted off with a carbon fiber record brush and with a velvet brush as well. And see to it that the paper sleeves are free of dust particles also.

This method will also work with individual records. If you have an empty box, you can follow the method described above. Take the records out of the outer covers and place them in between cardboard sheets. If you do not have a box at your disposal place the records as shown in the drawing and keep them tightly stored for at least a month. This method works only with vinyl from the 1960s, 1970s and 1980s. Not always for 1950s mono disks. Give it a try. And if it does not work you always can take more drastic measures.

I bought a box with the complete chamber music of Johannes Brahms. The records were hollow shaped like saucers. I did put several sheets of cardboard in the box. And guess what? After 2 months I discovered that the records were flat again and remained so. And it also worked with Mozart's Violin Music played by Henryk Szeryng and Ingrid Haebler as illustrated on this page.

It is important to check the LP cover. Sturdy cardboard covers may be no longer completely flat. Chances are that a new warp will be produced easily. Also gate fold covers may do harm and be the cause of a slight warp at the spine, typically when it contains 2 records. In some cases it can be wise to put one or more LP's in a generic cardboard cover.  
Pressings of 180 and 200 gr can be tough to correct.
A warp in a pressing from the 1950s and 1960s needs some time to be corrected. "Flimsey" 1970s and 1980s pressings can be corrected rather easily, although care has to be taken that the memory of the vinyl is fully erased over time and the record does not "flip back". Warps in heavy 180 and 200 gr. pressings are a different matter. They are not as easily corrected. I have a special section on one shelf reserved for all the records that need correction. Again all these records are taken out of their original cardboard covers and are stored in their inner sleeves in between flat card board sheets/separators. A stronger sheet of card board or even wood devides the correction section from the rest of the records on that shelf. See to it that the records are dust and dirt free. It is best to clean them first and have new inner sleeves before they are stored in this way. The records on that shelf should be in a very tight position so that it is not easy to get them of the shelf. Leave them there for a couple of weeks. You may want to check after some time to see if there is an improvement and to what extend.
Prevent and Correct Warps in 78 rpm Shellac Records.
The same goes for warped 78 rpm shellac records. For single discs in individual sleeves as well as for albums. Albums can have too much room (separation) between the subsequent Kraft sleeves.
Use sturdy cardboard which is completely flat. Cut out square sheets measuring the size of the paper sleeves of the album.
Insert these cardboard sheets between all discs as shown in the picture.

This is how it should look like. Now store the album vertically on the shelf in a tight way so that sagging is not possible. You will see that after several weeks or a month the records have become flat again.

It is easier to correct 12 inch discs than 10 inch discs. I used this method for a Deutsche Grammophon box with concave (dished) vinyls as mentioned above. But I also used it for the Cortot-Thibaud-Casals 78 RPM album shown above.

In both cases the results were very good. The DG Tulips had become completely flat. And the shellac discs were now really playable. I expect that this method is also valid for most of your warped records and that it will improve your collection and your listening pleasure.
That is to say if you have patience.

Other pages of interest:

History: 25 Years CD Ortofon, Garrard, Decca, Tannoy
Your Desert Island Discs Lp Cleaning & DIY Cleaning Formula
Garrard 4 & 5 HF
Turntable & Cartridge Adjustment
The Universal Stabilizing Ring SACD: Upsampling & Noiseshaping
URSR: Review in PFO 20
DIY: Turntable Weight/Clamp
URSR: Review in HiFi World LP Lists
URSR: Picture Gallery
URSR: Positive Feedback Award
The TD124 page
Joachim Bung: Swiss Precision
Mengelberg's St. Matthew Passion Plinth for Technics SP-10 mk2
Paris Jazz The Sound of The Turntable Mat
CLASSIQUE 777 Lp Record Covers The Treasure Trove
Klaas A. Posthuma - Remembered Ernst Lumpe: Allegro-Royale Pseudonyms
Steinway-Lyngdorf Model D Infinity KAPPA 7 A Loudspeaker Systems
The Turntable Mat - Page in Russian Ajuste de un giradiscos
Phono Cartridge-Headshell-Plinth
Alfred Wu: Collector's Illustrated Vinyl Bible
The Sound of Tubes and Transistors
Porgy and Bess
Elisabeth Lugt Soprano Active Loudspeaker System
Marie-Claire Alain, Organist Phono Cartridge Optimizing
Decca London Ribbon HF Loudspeaker Gold for Bernard Haitink
The Joy of Well Positioned Speakers Rabco SL-8E Tangential Tonearm
Vintage Equipment Mercury Living Presence Records
The Long Playing Record Guide HiFi Tunes: DAS KLASSIKERBUCH
The SP10 Page DIY:Tonearm Building
Stefano Pasini: German Perfection The Bullet Plug
Record Shops in Amsterdam Violinist/Violist Paul Godwin
Acoustic Revive R77 Generator The Remington Site
How to Correct WARPED Records Mercury Recordings on Fontana
Nostalgia: Violinists on 7" 45 rpm Contemporary Records - Lester Koenig-
DIY - Draaitafelconstructie - in Dutch Concert Hall - Musical Masterpiece Society
NOTES: The Belt Drive Turntable CINERAMA and Trinaural microphone Placement
Cook Livingston Binaural Recording System

Page first published on June 29, 2009

Sound Fountain

Audio&Music Bulletin - Rudolf A. Bruil, Editor - Copyright 1999-2009 by Rudolf A. Bruil and co-authors