Not very keen on actually doing this but I've been reading lots of articles and posts of people sound deadening their cars with various materials...

 

Our cars generally have a lot of empty spaces, particularly behind the boot liner and I was wondering if it's a nonsense idea to fill all those spaces with fluffy blankets like the one in the pic?

 

I couldn't help but notice how well these things absorb sound.

I'd be concerned they would absorb moisture from the air & not dry eventually causing corrosion.

 

I'd prefer to use a proper sound deadening material if you are going to the trouble of dismantling trim.

I see your point.

 

There already is open cell insulation behind the liners and that didn't catch moisture in 10 years. 

 

Hoping to keep the discussion going.

If you put one of those furry blankets in water how much water does it hold and how much heavier does it get if it does and how long does it take to dry?

If you hold a flame to it does it burn?

It probably holds water just as well as a regular towel and it does take ages to dry (often more than one drier cycle before it's completely dry).

As for the flammability, it probably burns quite well and might also melt to some extent.

 

I have no idea how much water can the open cell insulation in the car hold and I would rather not try and see if its flammable but I guess it does hold water just as well as the flurry stuff. 

 

Another issue the flurry stuff might have is static.... come to think about this actually this might easily rule it out as a DIY sound insulation material...