Question in regards to blown head gasket on my 1995 ford taurus 3.8l gl

What is your question?

Any way to know when it's OK to use a head gasket sealer? Is it safe and will it Complicate replacing the head gasket in the near future? I'm curious because I'm pretty sure my car has a blown head and I'm going to block test it today.

How long has your 1995 Ford Taurus had this problem?

2 weeks