cleeds was the first to offer the most effective way to flatten warped records....heat and pressure. I have not used Vinyl Flat but it seems that you can get the same results for a lot less money.
Home oven temperatures can vary greatly from what the setting (dial/digital) is to what the actual temperature is. An oven thermometer would be useful. Placing the record between 2 sheets of glass is a good idea but the main thing to consider is that the bottom support surface is very flat and sturdy (unless the glass is very thick).
If you try the DIY method start with a record that is warped and is not of particular value to you. That may be hard to find. If you use a warped record you purchased from a vendor and the vendor accepts returns, make sure you don't cause any visible damage to the record.
In the Summer months I have used parchment paper placed on both sides of the record, solid supports top and bottom, and HEAVY weight on top. Do that near a window or open area that receives direct sunlight, walk away, and forget for a day or two. This time of year that's probably not an option. But, the main things to pay attention to are flat surfaces, mild temperature, heavy weight, and time. Good luck.
Home oven temperatures can vary greatly from what the setting (dial/digital) is to what the actual temperature is. An oven thermometer would be useful. Placing the record between 2 sheets of glass is a good idea but the main thing to consider is that the bottom support surface is very flat and sturdy (unless the glass is very thick).
If you try the DIY method start with a record that is warped and is not of particular value to you. That may be hard to find. If you use a warped record you purchased from a vendor and the vendor accepts returns, make sure you don't cause any visible damage to the record.
In the Summer months I have used parchment paper placed on both sides of the record, solid supports top and bottom, and HEAVY weight on top. Do that near a window or open area that receives direct sunlight, walk away, and forget for a day or two. This time of year that's probably not an option. But, the main things to pay attention to are flat surfaces, mild temperature, heavy weight, and time. Good luck.