Whatever bend you get will flex right back, unless you heat the record in the oven first. So don't do that.
I've tried several versions of clamps. I prefer clamps by far over weights. But you are right to worry about the platter being dished out. They do that because the label area is thicker. But then if clamped hard enough into the dish it will actually raise up the edge of the record, when what you want is the opposite, pushed down.
The solution is a small o-ring or washer fit over the spindle and thick enough to raise the record just a tiny bit above the platter. Then the clamp will slightly bend the record down onto the platter. Done right not only will the record lay flat it will actually press out and flatten slightly warped records. Or even not so slightly. It all depends on the clamp and the washer.
Mine is custom and you can make one too, or hunt around for one with these important features. Reflex clamps grip any spindle. Threaded clamps if your spindle is threaded. Either one is fine. DYODD.
I've tried several versions of clamps. I prefer clamps by far over weights. But you are right to worry about the platter being dished out. They do that because the label area is thicker. But then if clamped hard enough into the dish it will actually raise up the edge of the record, when what you want is the opposite, pushed down.
The solution is a small o-ring or washer fit over the spindle and thick enough to raise the record just a tiny bit above the platter. Then the clamp will slightly bend the record down onto the platter. Done right not only will the record lay flat it will actually press out and flatten slightly warped records. Or even not so slightly. It all depends on the clamp and the washer.
Mine is custom and you can make one too, or hunt around for one with these important features. Reflex clamps grip any spindle. Threaded clamps if your spindle is threaded. Either one is fine. DYODD.