I'm looking for info about blockchain.com, which has been around since 2013. I've got about 0.15 bitcoin in there and I still have the original email used to set it up. I also have the 18-word recovery phrase, but the password got changed. I have the old one, but the new one isn't fully correct. Is there any way to get my funds back from this wallet?
I'm having difficulty understanding what the trouble is. Do you have the wrong password, or the wrong 18-word seed phrase?
If you have the correct 18-word seed phrase, you can use Electrum to restore the wallet. Make sure to download from the official site and verify it, here's a guide to help: https://bitcointalk.org/index.php?topic=5240594.0
Once you have Electrum installed, create a new wallet, select standard wallet > I already have a seed phrase, then enter the seed, then click the options button and select Bip39.
If you don't have the correct seed phrase, but you have the original email, contact Blockchain.com's technical support, they will be able to help you.
No, it can not work. BIP39 seed phrase is 12, 15, 18, 21 or 24 words long. If it is 18 words, Blockchain.com has that before the introduction of BIP39 seed phrase.
Maybe this can be of help: https://bitcointalk.org/index.php?topic=5186752.msg52546778#msg52546778. Also read the whole thread.
OP, the last part in your post is confusing! Do you still have the 18 words and only forgot the password or the other way around?
Since this is a blockchain(.info) wallet created in 2013 then it cant be an HD wallet. The 18 words you have arent a wallet seed (as Charles-Tim said). Its a password recovery phrase.
If you still have the recovery phrase (18 words), you can use this tool to recover your password.
Some info here:
https://cryptoassetrecovery.com/posts/how-to-recover-blockchain-legacy-mnemonics
Do you still have the same email address you signed up to blockchain with?
If not:
https://cryptoassetrecovery.com/posts/not-receiving-blockchain-authorization-emails
For those who are confused, his recovery phrase is an "Account Recovery Mnemonic" which can only restore the Password (and WalletID on newer version).
But he mentioned that he changed it later so he should've backed-up the new recovery phrase that's generated in Blockchain's security setting at that time.
@OP Given that, your current 18 words is useless since it's for the recovery of your old password.
And Blockchain doesn't store passwords in their server so their support wont be able to help you with it.
The best you can do is to request for your "wallet.aes.json" file from their support.
And try to bruteforce it with BTCRecover with your commonly used passwords and their variations.