I have a transaction currently in unconfirmed limbo for 24+ hours. It was from an old 0.15 bitcoin core wallet, and I guess the fee was set too low. The old version of bitcoin-qt does not support replace by fee, so I have attempted to issue a double spend with higher fee. The double spend is not being picked up though, and the transaction id does not show up on any block viewer sites.
Will the original transaction drop from the mempool after a certain time period? Is there another way to issue the double spend to make it work and take precedence over the original?