I've read several posts about soundproofing a Bronco...
I had an idea and wondered if it might work.

I pulled out all the interior trim and looked at what I could put to soundproof.

I was thinking of using old clothes between the trim and the sheetmetal. Instead of donating or selling the clothes, I could use as a soundproof system...

Go ahead laugh!!

I was really thinking about using Fiberglass Insulation. You know, the type used in homes. It will keep the truck cool in summer and warm in winter.

What do you guys think?

- Stranger

 

LOL, you gonna get Bob Villa involved?


Just kidding, You're gonna end up taking all those clothes out. Sometime, somewhere, the seams are going to leak and soak into the clothes. That would make prime place for rust to start to grow. Don't be a cheap, buy some sound deading spray and spray the truck. There are some that are in your local parts store, ready to use. OR, you can always buy some Dynamat (the good stuff) and go at it.

 

You may want to try offset printing blankets. Go around to your local printshops and ask if they have any old, used, beat-up blankets from their presses. They're just a rubber compound vulcanized to a cloth backing. You could get anywhere from around 11" x 17" up to over 23" x 35". Depends on what size press they run at any particular shop. I have six from the shop I work in that are just over 20" x 28". They'll go behind the door panels, ashtry in the back, floor... wherever I want to kill rattles or deaden sound. Cheaper than Dyna-Mat. I don't see why any shop wouldn't give them to you. They just throw them in the trash when they are done with them.

 

So which would work better?
Spray or Carpet padding?

I think padding... Ford uses it.
I plan to use it behind the rear trim covers and behind the door covers and the floor.

 

But spray wont soak in moisture and start a rust spot or start smelling. Dyna mat wont either

 

Inside doors, top and fire wall, I've used an aluminum rust inhibitor then glued foil faced bubble wrap. It is good deadener and will not pick up moisture. It will not work for floors ( the bubbles POP :lol

 

I saw that foil bubble stuff at HomeDepot.
Any thoughts on fiberglass insulation?

 

I can tell you about sound-deadening materials:
There are three different type materials, used for three different purposes.

On the firewall, floor, and wheel arches you want <B>barrier</B>.
The important property of a good barrier is that it be heavy, in terms of pounds per square foot, and that it be limp, so it won't vibrate.
Barrier blocks the transmission of sound, like road noise or airborne engine noises. It works to keep airborne noise out of the cabin.
A good typical barrier is "loaded" vinyl, so called because of additives llike barium sulfate used to increase the weight per unit area. A good barrier will weigh 2lbs per square foot. An even better barrier under your carpet would consist of 1/2" of foam (this can be closed-cell foam so it won't absorb moisture) covered by a 2-pound (per sq ft) barrier underneath carpetting. You want the foam to be thick enough and just stiff enough that the weight of the barrier doesn't squash it flat. You now have what is called a de-coupled barrier.

For an interior, you'd like lots of the surfaces to be <B>absorbers</B>, or have absorber behind them.
A typical absorber is open-cell foam or low-density fiberglas. Absorber works by dissipating the sound energy in the fibers or in the cells of the foam, so sound must be able to get to the absorber.
That's why these materials need to be behind a cloth covering that will readily permit airflow; if you can't blow through the upholstery covering, what's behind it will not work as an absorber.
So install a fabric headliner with <B>open-cell</B> foam or fibreglas (1" thick minimum) behind it - thicker is better - and install a good deep-pile carpet over the barrier. Use cloth upholstery on the seats and seat backs - you want the maiximum square footage of absorber.

Finally, there are <B>dampers</B>, or damping sheet material. Although this material looks very similar to a good barrier vinyl, they are not at all alike.
Damping sheet is used on your door outer skins to prevent ringing noise caused by the sheetmetal vibration when the door slams, and it does this by acting exactly as a shock-absorber does on your suspension - it provides viscous damping, that is, a force opposing motion that is proportional to velocity, not displacement. You can also use damping sheet on wheel arches if you have a problem with rocks hitting bare sheetmetal. Fender liners are better for this though.
You can add quite a bit of damping sheet in addition to what the factory uses, including on flat surfaces of the door inner sheetmetal, and make your door-slam noise much nicer, more of a "thunk" than a ring. Loading a door up with damping sheet is what Mercedes and BMW do to make the door closing sound like the bank vault closing.
Damping sheet thickness should be I think at least half the thickness of the sheetmetal it's applied to ijn order to have any useful effect.
--------------------
So: in summary, I don't think you want old clothes NOR fiberglass for "sound deadening".
First decide what you really want to do, figure out where your noise is coming from, and select your material accordingly.
And take a look at the firewall - one little leak or missing grommet can make a huge difference in the noise getting through.

 

Dang that's good. I couldn't of said that better.

 

Thank you RedBob!!!!!!

 

De nada - eets my yob, man!

 

Good explanation - which category does Dynamat fall under?

 

Excellent write up. Check out www.b-quiet.com for what products do what.

 

Dynamat has a range of products:
the original Dynamat is damping sheet, used to reduce panel vibration; at .7 lb/sq ft, it will also act somewhat as a noise barrier, but other products will do better for that purpose. As the Dynamat website notes, this stuff is good for door panels or to prevent vibration or buzzing of speaker enclosures.

Dynamat Extreme is also damping sheet, but with a very thin layer of aluminum on top to provide heat resistance.

Dynaplate is constrained-layer damping sheet, which gets improved performance by having a thin layer of aluminum on top, so it weighs much less than ordinary damping sheet for the same level of performance. But it's sure to cost much more. This looks like a really good product for its intended purpose, but being lighter would have little or no sound barrier qualities.

Extremeliner is a lead barrier sheet - if installed upside down, you'd have a decoupled barrier, as mentioned previously, which is the very best kind - as long as you completely cover the panel that is exposed to noise, and there are no holes or "flanking paths" for the noise to get around the barrier. However, the weight is lower than the optimum 2lb/sq ft, and the only acoustic properties listed on the Dynamat site are those for an absorber (!) not for a barrier. And those properties aren't especially good.

The hoodliner sounds like a good product, since it would reduce the noise level in the engine compartment, so there'd be less noise coming through the firewall. <B>BUT</B> the product description for the hoodliner contains one ridiculous statement: "If all the foam cells were open, sound waves would simply pass through." This is absolute nonsense!
My only observation is that it could stand to be thicker; it should be at least an inch thick, two inches would be better. The quoted acoustical properties look fairly good, but something like E.A.R. Corporation's Tufcote E-100RM is better, especially at engine noise frequencies.
Hoodliner can also be used on the outside of the firewall, and the ideal firewall solution would have a good absorber on the outside (engine side) with a good decoupled barrier on the inside, over damping sheet. This would get a little expensive, but it would really prevent noise from getting through.
Regards,
Robert

 

B-Quiet lists a product called V-Comp which is an excellent example of decoupled barrier, but with this you have to keep in mind that the foam side must go toward the metal on for example a firewall or a floor. Otherwise, the foam just acts as a pretty poor absorber, since it's not very thick.
And I'm not sure that 1/4" foam is thick enough for a decoupled barrier to be used under carpet, since the weight of the barrier layer plus that of the carpet will probably squash it flat.
regards,
- R