Heloc funded investment tax question

[William Wallace]

Hey, I was toying with the idea of using a HELOC to fund a non-real estate investment, specifically buying some debt. It seems to me that even in the perfect situation, where I get paid like 12% interest rate with no chance of default, and I get a HELOC with around 6% interest rate, I'm going to have to pay taxes on the interest I collect, but I cannot write off the interest I pay, and it will probably not be worth it. Am I correct on this?