It seems you might not have a clear understanding of how an Abstract of Judgment works. A judgment creditor can record an Abstract of Judgment in any county in which the judgment debtor owns (or may own) real property. It does not matter if any such real property is co-owned with other individuals.
In California, the recording of an abstract of judgment merely provides notice of a judgment. An abstract of judgment can be recorded against a judgment debtor in each one of the 58 counties within the State of California. There is often a misconception that the abstract is recorded against a specific property. It is not necessary that the judgment debtor own any real property in any county in which an abstract of judgment is recorded. The judgment lien created by the recording of the abstract is enforceable against real property which the judgment debtor may own in the future.
Frank W. Chen has been licensed to practice law in California since 1988. The information presented here is general in nature and is not intended, nor should be construed, as legal advice for a particular case. This Avvo.com posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, please consult with your own attorney.
I agree with Mr. Chen. It does sound like there is another issue in your question, which is whether or not the lien created by recording the judgment is "scraped off" by the foreclosure of a tax lien. I cannot answer to CA law, but in Arizona, such a foreclosure would eliminate any encumbrance on the property of a junior judgment lien. The problem we face with your question is that you are not making it clear as to whether you are the person with the judgment recorded against them or if you are the person looking to foreclose the tax lien or buy from someone who foreclosed the tax lien. You have to give us the facts involved for anyone to be able to confirm any advice you have been given.
Disclaimer: This answer is provided for informational purposes only, does not constitute legal advice, and does not create an attorney-client relationship. I am licensed in Arizona and can only provide general comments on matters outside of Arizona law. Actual legal advice can only be provided after a direct consultation in which all of the relevant facts are considered before providing a response.