Using small amounts at a time apply the roofing tar with your roller in short and smooth strokes.
Using roofing tar for undercoating.
Undercoating spray can be purchased as a diy product but it s tricky to apply so it s best to use this method at the dealership on a new vehicle.
It s a true temp fix as eventually the entire metal under the patch will rust away.
You can use a black roofing tar cement asphalt in a gallon container.
The coating itself is a tar like substance that sticks to the undercarriage components and acts as a barrier to resist salt moisture oxygen and other items that lead to corrosion.
Consider leaving your container of roofing tar in direct sunlight for about an hour.
Use the broom to clean your roof before applying tar roofing.
When there is no debris left you are ready to apply tar to the roof.
The sunlight will thin the tar and make it easier to apply.
Problem with roofing tar is the metal continues to rust.
Probably not a good idea.
And can you imagine how hard it would be to take off in a few years.
The stuff is fine for the top of a flat roof but probably terrible for the bottom of a car.
You mix the black roofing cement asphalt with mineral spirits to get a brushable consistency and just brush around all the areas on the undercarriage that ford originally brushed it on.
I ve got photos attached of my gold award winning undercarriage on our 69 mach1.
Use por 15 and fiberglass for a permanent fix.
Start in the corner furthest from your ladder.