I actually didn't realize there was something a mat under the hood - mine's missing!

 

MG -

I agree with you. All good. I've made a lot of decisions about my truck during the reno. Everytime, you have to make a change or repair that is consistent with the finish of the truck. My inexpensive insulation was a throw in although I am liking it now...for heat and noise. Also I used an 1/8" galvanized and painted sheet metal as a top layer sooo. I plan on using the same stuff on the interior ceiling to try and drop the temps a few degrees in the cab.

It's not going to be the same as the technologies you mention.

I no longer have that hood blanket and have been thinking if I should replace it before I finish the exterior.

 

I'm curious, how did you prep the galvanized steel, or what paint did you use? Most paints will not readily stick to galvanized, speaking from experience...

 

maybe it's not galvanized steel. they call it galvinizado. i cleaned it with KBS Klean product, then painted red rust inhibitor enamel. the underside got the insulation with foil tape surround and the upper side got an additional coat of the black kbs rustseal. looks like it's holding very well....but its got a long way to go.

 

You can get a reasonable improvement for not a lot of money and time by sticking a rectangle or two of Dynamat-type material (there are many similar products) on the inside of each door panel and rear quarter panel. The mat doesn't have to cover the whole metal surface; you just need to add some mass to the center of the panel to reduce vibration, thus reducing sound transmission.

I'm sure pros have far better methods, but this helped my truck and wasn't a big investment in time or money.

 

Yes that definitely helps and you hit the nail on the head, you don't need much. About 25% coverage by area is adequate, beyond that and you would be better off combining with other products. Constrained-layer damping (such as Dynamat) addresses structure-borne noises (rain/hail, engine vibrations, etc.) but will have little to no affect on airborne noises (wind noise, tire noise, exhaust drone).

Clean the area where you will apply it with alcohol and be sure the surface is completely dry. Apply with a heat gun or hair dryer, getting the material warm and flexible first to increase tack. Apply pressure with a roller from the center outward, cut slits with a razor to remove any stubborn air bubbles. On vertical surfaces such as door skins I prefer to put a strip of aluminum tape at the top so it won't droop down over time. Same goes for roofs, but I go all the way around with tape on those (and apply in smaller pieces).

Be sure you want it where you put it because it is difficult to remove and should be considered practically permanent.

 

Good tip about the alcohol and aluminum tape across the top edge, will do that next time.

 

Just like so:



Except in a Rover.

 

so those bits of silver are the protection and the orange is the bottom of your truck?

if so can't believe those help at all with all that uncovered space.

i tried to cover as much as possible even if i used a cheaper foil/glass solution. im very happy with my results (as Ive said). i can feel a very different temp where the steel/insulation is and where it is bare floor.

...and im gonna do it on the roof soon...mostly for heat.

 

They are not there for blocking, they are only there for damping. In other words killing resonances in the panels. Like I stated earlier, around 25% coverage is all you want/need for damping. I was just demonstrating how I tape it on for vertical surfaces so gravity won't tend to peel it off.

If I wanted blocking I'd use mass-loaded vinyl or thin sheets of lead. But that won't happen in this car as we're not wanting to add much weight. In your case, I'm sure the steel is heavy enough to provide very effective blocking, and the foil/glass is providing thermal benefits.

And no, it's not a truck, nor is it mine, it's just the latest car I've been working on...