Flattening warped vinyl LPs?

[Light Capture]

I have a very badly warped LP. Can I flatten it out buy putting on a flat surface w/ a flat piece of marble on it? Or is there a better solution? How long does it take? Your answers are much appreciated.

[struth]

2 sheets of glass and in sun for a short while often takes much out. or even in cool oven

[Light Capture]

Thanks Struth. I have 2 pieces of thin marble tiles the correct size. I'm trying indoors and if it doesn't work I'll try the hot sun.

[Barry]

I wish you all success with using glass or marble sheets in a warm environment, but you may find that despite being initially successful, the warp will return.

Warps are usually caused by removing the newly pressed disc too quickly from the mold. PVC ('vinyl') is thermoplastic, so if heated towards a temperature where it softens and placed under pressure any warps ought to be removed, but there is no guarantee it will be permanent.


I have an LP with a bad warp at the edge, which means that the first track on one side cannot be tracked, whereas the corresponding track on the other side can be tracked if I disable the anti-skating bias of the arm. Try as I might, I have never managed to permanently remove, or lessen the severity of, the warp.

[Light Capture]

Thanks Barry for the info. I'm cautious about heating it to much with the sun as I don't want to distort the groves. Best seems to heat marble in sun then bring inside and press vinyl as marble retains heat for a while, kind of like a pizza stone. It did a pretty good job but it does seem like the straightening didn't hold 100%. I have it pressing inside and will try heating marble in sun tomorrow and press inside again. Maybe over time it will hold.

[willbewill]

Use a flattening service who have one of these machines?

https://everyrecordtellsastory.com/2020/03/13/warped-record-heres-how-to-get-it-fixed/

[Light Capture]

I seem to be gaining headway w/ the smooth polished granite (not marble, my bad). I've removed the worse of the offending warp, and will have it sitting in a sleeve between the granite tiles indoors for a while under room temperature. I'll get back some time with my results.