Acoustic/thermal

[HCA]

A while since I stripped an interior back to bare metal for new sound/heat material, but I am at that stage with my LHD conversion.

I was converted to Dynamat many years ago and would continue, except, I wonder where technology has gone of late? There is much talk of ‘paint on’ material now and wonder if anyone has experience and or comments? Or should I continue with Dynamat??

[billwill]

Bare Metal?? The interior of an Elan or +2 is nearly all fibre-glass, but I guess we know what you mean

There isn't much thermal insulation ex factory, just some layers of thick woolly stuff.

Have a look though these links.

https://www.google.com/search?q=dynamat

[HCA]

Thanks for this, however, again though, I am well familiare with Dynamat , I am looking for comments on anything that might be better than dynamat - if such exists.

[alanr]

Dynamat is just so very heavy! Far too heavy for a Lotus...Keep it light!
I much prefer the traditional type of sound proofing underfelt.
https://www.woolies-trim.co.uk/p-1384-s ... ening-felt

Alan

[Slowtus]

Dynamat is just so very heavy! Far too heavy for a Lotus...Keep it light!
I much prefer the traditional type of sound proofing underfelt.
https://www.woolies-trim.co.uk/p-1384-s ... ening-felt

Alan

Superllte is about less 27% than Dynamat and there are a bunch of alternatives

https://soundproofliving.com/dynamat-al ... omparison/

As for the increased weight - meh. Well worth it.

[phil1800]

Hal,

Dynamat and alternative materials are mass dampers with an added aluminium layer to reflect heat. They are designed for steel/ aluminum car bodies to minimize resonances introduced by engine, suspension and wheel vibrations and noise. The self- adhesive layer adds to the effect of the heavy layer by creating a ‚constraint layer‘ damper with the body panel it is attached to: The mass and stiffness of the heavy layer dampens the amplitude of the resonating body panel, thus minimizing or canceling the ‚loudspeaker‘ effect of the metal panel. Fiberglass has superior acoustic/ NVH properties than bare steel because of it‘s construction (layers of fibers with resin and the body thickness acting as constraint layer). That said, fiberglass and other lightweight materials have other acoustic issues, that are more air- borne noise related than structure- born noise (see above). Canceling air- borne noise is much more ‚involving‘, i.e. no easy solutions (for a car) are available.
What I have to my DHC NVH wise is to improve sealing to all dash/ firewall/ body cavities and adding a multi layer aluminium foil heat barrier to the dash and floor pan. The al heat barrier I use is unfortunately not available in the aftermarket.

Have a good year 2023!!

Philipp

[HCA]

Thanks.

I am quite au fait with Dynamat and used it in the past many times.

I am really interested if anyone here has used liquid products such ss Spectrum second skin or Lizard skin:
https://lizardskin.com/sound-control/
These are hailed by the US car restoration shops as the way foreard, but expensive.

Looking closer though, whilst available and widely used in the US and Australia, does not seem available in EU!

Why is the EU so far behind in auto products? I once visited a car restoration rally in the US and was blown away by some of the cars entered by ordinary hobbyists and as a consequence do laugh at specialist car meets this side of the pond

[vstibbard]

The lizard skin products used here in Australia are generally used on Ute bed liners as the protective layer that also stops rusts from scratches. Some manufacturers use it as an OEM finish.
Vaughan

[Slowtus]

But wait, there's more!
https://www.jbc-tech.com/blog/posts/eli ... -priority/

A is better than B, C is better than D and on and on...much discussion but very little empirical data here (and everywhere else)

I have used Dynamat and similar on a variety of cars and have always been satisfied with the result.

Noise diminution? Not so much as a reduction in thrum, drum and hum and a general feeling that everything ALWAYS feels more 'solid' when these materials are applied.

Do NOT apply anything if you are looking to diminish noise by a considerable extent because it won't but it will do as I mention above.

[billwill]

Thanks for this, however, again though, I am well familiare with Dynamat , I am looking for comments on anything that might be better than dynamat - if such exists.

There are several comparison pages on that link that I gave above.

[Slowtus]

[quote="billwill"]
There isn't much thermal insulation ex factory, just some layers of thick woolly stuff.

Was that not more for 'fit' than anything else?

I dunno, just asking.

[h20hamelan]

The fibres used by Mercedes and Volvo between body and carpet in the 80’s-90’s are great.
Thick, dense, abrasion, fire, woven, and fairly good for sound deadening.

[mbell]

I just used foil lined modern underlay stuff. It's a little thinner than the original but the foil will help with the heat. Reasonably light and cheap, but probably not the best solution available.

What you should use is really down to what your trying to do and what you care amount most (noise, heat, weight, cost etc). So hard to give specific advise.

[gav]

Thinking ahead to the next rebuild or to a repair - how easy is it to remove these self adhesive noise reducers.
I admit that I battled with the removal of the original should proofing because the adhesive was very effective but if one were to apply a modern product and subsequently need to carry out a repair or refurbishment, how removable are they and will resin/mat bond over any remnants of the modern self adhesive that cant be removed?

[skyarch]

Anyone try this? From Second Skin Audio, I'm just starting the reassembly of the doors on my DHC.
Leaning towards this since you can install it with contact cement.


https://www.ebay.com/itm/293258580298?c ... X4EALw_wcB

This is 3/8" thick, but available in 1/8" too.