A typical vinyl record can start warping due to heat at a temperature of 140 f 60 c and can melt at temperatures exceeding 212 f 100 c.
Temperature vinyl records warp.
Determine whether or not that fixed the warping.
Pvc starts to decompose when the temperature reaches 140 c with melting temperature starting around 160 c.
Preheat the oven to its lowest temperature setting.
From good old wikipedia store in use lps at a temperature of 65 to 70 f 18 to 21 c.
Pressure against the record and at room temperature below 75 degrees f.
Though relative humidity rh is considered less an issue for vinyl than other recorded media 13 it is recommended that lps be stored at 45 to 50 rh.
Those in long term storage should be kept at 45 to 50 f 7 to 10 c.
Turn the heat off.
Place the record between the two panes of glass making sure the record is clean first.
Fortunately warped records can often be fixed so you can be back to rockin and rollin in no time.
Direct sunlight increases in temperature and or uneven storage pressure are the principal components that can lead to warping vinyl records.
Let the record cool down to room temperature.
Put your vinyl glass sandwich in the oven for 30 minutes.
Warped vinyl can lead to a wobbly sounding rendition of your favorite song.
Once the oven has reached the right temperature carefully slide the record and glass combination onto the oven rack.
Depending on your oven preheating should take between 10 15 minutes.
The linear expansion coefficient of rigid pvc is small and has good flame retardancy the limiting oxygen index loi being up to 45 or more.
If a record is improperly stored and or kept in a high temperature environment the vinyl may warp and the record may become unplayable.
Other factors such as humidity sunlight exposure and improper storage can drastically impact the resilience of a record.
Preheat the oven to about 175 f 79 c and place the record inside.
Improper storage exposure to heat and cats can lead to warped vinyl.