Bitcoin Forum

What happens to your old wallet when you reconstitute your private keys on a new cold wallet? I'd like to move over to a bitcoin only wallet. I'd add a passphrase to the new wallet for an additional layer of protection.

Do not import your old wallet private key but to generate new seed phrase on your new cold wallet.

You can add passphrase which makes your coins to be more secure and safe. But do not lose the passphrase either, just as the seed phrase too. Both should be kept safe and securely in different locations. Also having two or three backups.

If you lose your seed phrase, you coin would be lost. If you lose your passphrase, your coin would be lost.

Nothing would happen to the old wallet since you would be using the same private key, but you shouldn't do that. Instead, sweep the private keys instead of importing them. You wouldn't want to risk importing a private key/seed that might have been compromised to a cold wallet. Which cold wallet are you going to use?

Nothing since it'll be a different wallet since adding a "BIP39 passphrase" would change the entire hierarchy of keys.
It wont derive the correct private keys from your old Bitcoin wallet.

That's assuming that you meant "BIP39 Passphrase" and not just the "Passphrase" for wallet encryption.

Was your old wallet a cold wallet? If so, nothing changes. Even better if you keep your old copy too, just in case.
If your old wallet was a hot wallet, moving the private keys doesn't make it a cold wallet.

I guess LoyceV is correct. BIP38 too is called passphrase. While OP is only referring to private key. Which likely means this is about a private key wallet, like paper wallets. If that is it, adding passphrase encrypts the wallet. If the old wallet is an online, what if the private key has been exposed before you encrypted it? It only means that the encryption is useless. Also useless if you do not delete the old wallet if it is an online wallet.

But if it is HD wallet and adding BIP39 passphrase, nc50lc is right. But because it is another keys and addresses entirely if you add BIP39 passphrase. But why not generate new seed phrase instead and add passphrase.

It would be cold to cold. I'm hoping to avoid memorizing a new seed phrase

Are you absolutely certain your current set up is 100% airgapped and has never once been online? Do you want to briefly describe your current set up?

You shouldn't memorize any seed phrase. Write it down on paper and keep it somewhere safe.

You are right, because writing the seed phrase down and document them as many they are will give a lesser problem for knowing or memorizing them, and if you think that you can memorised them you may skip some of the arrangement, I think it's quite understanding  that writing your seed phrase on a paper should be the safest way of memorizing them because of long stays before making use of that particular wallet because you can't remember all.

If you are unsure about your old wallet, you should move your bitcoins to a new wallet.

You can do it in either ways which both cost you transaction fee because it is an on-chain transaction.

• Moving your coins from that old wallet to a new wallet, after importing its private key and sending it to your new wallet.
• Sweeping it.
  
  • Sweeping your private keys into Electrum (https://bitcoinelectrum.com/sweeping-your-private-keys-into-electrum/)

That passphrase is a layer to protect others to access your private key. That passphrase can not protect your private key if you leak the private key. With a private key, others can import it and be able to spend your bitcoins.