BUT AM I NOT PUTTING MY HOME AT RISK?
If you borrow to invest in property, you are putting your home at risk, whether you secure it against your home or not. If property values fall and your investment mortgage is higher than the property value, you can't just hand back the keys to the lender and walk away. You personally owe the money and the bank will get a judgement against you for the amount due.
Having a separate mortgage for the investment property provides no extra security.