interior cracks

anyone one have advice on repairing cracks inthe interior floor and fire fall . I have cracks in several places that are not accessable from both sides . I have the heater box out and the thin strip at the top is cracked right at the upper most corner where the dash begins there is a four inch crack in the recess of the wiper motor. I bought the videos from Eckers but was disapointed Lambo68

I fixed a few of those on my car with epoxy and fiberglass strands.

If you can get to the area with a dremel, use the sanding drum to "V" out the crack. With scissors or a razor blade, cut up some mat fiberglass so you have short strands. In a small disposable container, first mix the epoxy parts then add the strands until you have some thing resembling a thin paste. You can trowel that mixture into the crack. On the floor, I'd do a layover type of repair instead of just filling a crack, it's under a bit more stress.

thanks that is the way I was leaning but wasn't sure Thanks again   Lambo68

After filling the crack as described,  I would make several layers of fiberglass mat on top of the area.  Layover was metioned, but do several layers.

Thanks Ken , I will do that most places but I don't think I can do that behind the heater box without cover the enter circumference of the opening . I am thinking the box won't be flush otherwise. Lambo68

Ken's right, several layers...... at the heater box, doc rebuild has a seal kit that should bridge an uneven surface.

 Thanks again I will take your advice and lok into a seal kit Lambo68