insulating a 359 Pete

You want to use the insulation for heat BETWEEN the heat source and what you want protected from the heat. So, if you wanted to keep your floor boards from getting too hot from exhaust, engine, drivetrain, and fuel tank heat you would use something like Lizzard Skin, Tempkote or Supertherm and spray it on the floor boards and firewall on the outside of the cab facing the heat source. This prevents the firewall/floorboards from getting too hot in the first place and allows your inside insulation to work that much better.

Most people put the insulation on the inside only, what happens here is the firewall/ floors get hot right away and the interior insulation has to fight that all day- it's a losing battle and an insanely inefficient insulating practice. Not to mention a colossal waste of time and money.

 

Luwi67 I like your suggestion. It makes sense when to stop to think about it. I wonder if unseen corrosion could be a problem down the road. I need to look up lizard skin.

 

Lizard skin looks to be a great product especially when you can use 2 of their products together for heat and sound.

 

As long as the spray-on insulation seals well and doesn't absorb water, it should help prevent corrosion. I recently sprayed bedliner on the undercarriage and lower body panels of my pick-up. Seems to reduce roadnoise, never really noticed much heat coming through the floor so I can't really comment on that. Mostly hoping for corrosion resistance.

 

Lizzard Skin, I believe is an elastomer coating with tiny ceramic beads in it. Like anything you want to adhere, prep is everything. Degrease the firewall and floors with a non residue leaving degreaser then wipe the panels down several times with any pre paint or wax and grease remover. Take a heat gun and make sure any seams are fully dry and, spray away.

As for corrosion, unlikely on an aluminum substrate. What hurts aluminum is dissimilar metals like steel and stainless steel, not moisture. Again if the prep is right then corrosion should be a non issue.

If your floors are sheet metal that is a different story, prep them and hit with epoxy primer first, key that and then hit with insulation. On aluminum you can even use a self etch primer before spraying insulation but, probably unnecessary.

 

Spray-in foam caan hold moisture and cause mold/mildew issues

 

When's the last time you saw insulation on the OUTSIDE of a house? Environmental protection is the reason it's put inside.

 

Recently, a lot of new buildings have the ceramic spray on insulation on the roof to reflect radiant heat from the sun. So do some of the new energy efficient homes, as well as RV's, school buses and some reefer trailers. That stuff is white and called Supertherm or Tempkote.

Lizzard Skin is meant for hot rods and it is dark grey.