PA tax upset sale question about mortgage

[Justin Summers]

I loaned  money to someone that has a property that is going to upset sale in Pennsylvania his property currently has no mortgage.  If I get that person to sign a mortgage against the property before it goes to tax sale for the amount they owe me and record it with the county,  I assume I would have a lien on the property that the purchaser at the tax sale would have to payoff to get clear title.  Even though the mortgage would be recorded just 2 days prior to the tax sale and wouldn't be showing up in  the landex records yet.  I assume it would still attach since the recording date is prior to the upset sale date.  Am I correct?