Roof foam or dyamat

[SplitDash]

I'm sure its been covered to death but ........

Do people glue in new foam (what glue?) or use sound deadening ?

I'm leaning towards sound deadening because I know it sticks like shit on a blanket 😄.

This whole project started because I needed to change the headliner and found so much rust so I never want to take it out again.

Am I over thinking it, 

Is is possible for vapor to condense on the roof skin and stain the liner ?

Thanks in advance

 

 

[calw]

I'd be asking the manufacturer of the sound deadening material about the temperature it can handle once installed.  It gets quite hot on the underside of the roof metal and it would be a bad day indeed if your heavy sound deadener started to lay on top of the headliner instead of being attached to the underside of the roof. 

 

The same caution applies to whatever glue you'd use for the foam.  I ended up using a closed cell foam that someone was selling here and a high temp spray on glue from 3M (sorry, can't recall the model number of the glue).  Stick on sound deadener certainly has a certain appeal for installation, as you aren't spraying messy glue all over the place inside that nice interior. 

 

The original very thin open cell foam (well, dust these days many years after the car was built) isn't the thing to use.  Not even sure if it every had a noise effect, being so thin. 

[TobyB]

I can almost remember what I typed last time...

 

If there was a very high temperature, high- adhesive spray product a little like

truck bed liner that had a 'we'll pay for damages when it fails' warranty,

that might be the way to go.  I've never seen such a thing, but I haven't 

looked in the last ten years.

 

Otherwise, adhesives are never a good idea in tension- it might not even be the 

adhesive's fault, but stuff stuck to ceilings always falls off eventually.

Neither are water- permeable substances, as the temperature differential across the roof

will lead to condensation.

 

If that doesn't rule out absolutely everything but paint, have at it!

 

t

 

[conkitchen]

7 minutes ago, TobyB said:

If that doesn't rule out absolutely everything but paint, have at it!

While I have done mat on the roof myself with success. I have not experienced the long term effect of doing so.  

 

What Toby said made me think, why not use a low expanding spray foam. When fully cured, one could sand down high spots and shape the rest to fit.  

 

See my tag line below. 

 

 

[zinz]

My painter used Lizard Skin sound deadener on the interior of my 2000CS when he was prepping the shell.  It goes on with a special gun, kinda like flocking a Christmas tree.  This was after an epoxy primer, adhesion was very good and I doubt it will ever come off on its own.

 

They also make it in a ceramic formula for use on the firewall for heat control.

 

Ed Z

[Dudeland]

Dang,  I wonder how the person is getting along with the carpet underlay that I put on the roof with contact cement, 20 years ago on my bug. 

 

 

[RogerRamJet77]

I’m thinking of using this from Amazon:   Abahub 394 mil 16 sqft Car Hood Insulation Pad Auto Sound Deadener Door Dampener Deadening Mat Heat / Cool Liner, Self-Adhesive Closed Cell Material (PE Foam Sound Deadener) 59"x39" 

Edited September 27, 2023 by rockyford77

[jimk]

26 minutes ago, Dudeland said:

Dang,  I wonder how the person is getting along with the carpet underlay that I put on the roof with contact cement, 20 years ago on my bug. 

 

 

Does it get above freezing in Toronto  ?

[Son of Marty]

I think Toby was being a bit tongue and cheek when he mentioned bed liner but it's a exhalant sound deadener and anti vibration coating  with the added benefit of making your car bomb proof, it will not come off and it works by putting the panel under tension as it dries eliminating most oil canning if you use it as a undercoating it will not chip or dent. 

[SplitDash]

Some good ideas guys.

I'm going to underseal the car with bedliner, never used it before so I'll see how that goes first.

Here is the dynamat extreme temp spec. cant see it being an issue

 

Temperature Range (Optimal Performance): 14F to +140F (-10C to +60C) Temperature Range (Resistance): -65F to +300F (-54C to +149C)

[Dudeland]

14 hours ago, jimk said:

Does it get above freezing in Toronto  ?

Once every 4-5 years.  It is really a pain having to mop up our igloos.  LOL

[calw]

5 hours ago, SplitDash said:

Some good ideas guys.

I'm going to underseal the car with bedliner, never used it before so I'll see how that goes first.

Here is the dynamat extreme temp spec. cant see it being an issue

 

Temperature Range (Optimal Performance): 14F to +140F (-10C to +60C) Temperature Range (Resistance): -65F to +300F (-54C to +149C)

I'd want to understand exactly what these specs mean, the first seems like it relates to audio performance, not stick to the roof-ed-ness.   No idea what the (Resistance) spec relates to. 

 

Online reports (from the internet where have of information is right part of the time) indicate that the car roof sheet metal can hit 180F or more.   Of course that number will be a bit different in Toronto than in El Paso or Tucson and depend a lot on you choice of paint color.

 

Bed liner seems like a brilliant idea !   Stiffening the roof to deal with lower frequencies is the most important part.  High Frequency stuff will be dealt with by the cloth headliner, no matter what you put above it.  Surface prep for it must also be important, but probably an easy thing with new painted metal.

[Paul5801]

As a point of reference, my garage door in Texas with direct sun hits ~137F.    

 

[SplitDash]

7 minutes ago, Paul5801 said:

As a point of reference, my garage door in Texas with direct sun hits ~137F.    

 

 

Holy shit,

Well I live in Ireland so I'm not overly concerned about heat.

Its gravity & condensation at I'm contending with .

[Paul5801]

I have been installing Damplifier from Second Skin in the ridiculously hot garage.  I have installed it on the floors, firewall, and behind the rear seat vertical-ish section.  The heat has not affected it at all.  It did not turn gooey or  really any noticeable difference.  I would have no problem installing that on the roof.  But, I have not gotten to that project yet.  They also make a spray-on version as well.

Damplifier™ Sound Deadening Mat - Second Skin Audio

WWW.SECONDSKINAUDIO.COM

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