my roof, it moves up and down, and I don't know why

[ssh 924]

Okay so for those of you who don't know what vehicle I have, It's a 1997 2door jeep wrangler hardtop. The hardtop is made of polycarbonate, plastic, something you get the idea.

So it flexes a good bit and wanted to hear what you guys would suggest for fixing it. Would cld tiles soak up some of the flex? just trying to brace the plastic so my sound output isn't wasted

Heres some pics:

[Duran 387]

CLD Tiles don't stop panel flex, they only combat panel resonance. The only way to get it to stop flexing is to brace it, steel tubing would work well.

[Kanaworm$ 292]

The CLD panels will help in adding mass to the surface, not sure it will completely eliminate the flex.

Don from SDS recommened that I get some aluminum and glue them to the surface of the back wall of my truck to help with flex.

[ssh 924]

I could weld thin strips of metal together in the shape of a rectangle, then use what to mount it on the plastic, epoxy, glue? hmm

Next thing is how would I cover this up so the interior doesn't look like hell

Perhaps Damplifier from secondskin? I've read it's pretty thick and might help stiffen everything?

Edited July 11, 2010 by stefanhinote

[xAndrew225x 8]

my roof is doing the same thing but its causing nasty rattles. will CLD tiles at least stop the noise?

not trying to hijack your topic

the cars roof isnt plastic whatever though, its metal. (99' corolla )

Edited July 11, 2010 by xAndrewx

[ssh 924]

my roof is doing the same thing but its causing nasty rattles. will CLD tiles at least stop the noise?

not trying to hijack your topic

the cars roof isnt plastic whatever though, its metal. (99' corolla )

I would definitely add tiles and some sort of thin foil material with adhesive such as damplifier.

I'm lucky that mine doesn't rattle since its plastic, but im still losing output lol

[Sir-Lancelot 216]

I wouldn't mess with it if it was mine. Not really an SPL vehicle anyway and it's going to look like shit if you go ghetto up the roof.

If it's not raining that top is supposed to be off anyway.

It's a jeep, it's nice, it's loud, life is good~!~!~!~!

[ssh 924]

I wouldn't mess with it if it was mine. Not really an SPL vehicle anyway and it's going to look like shit if you go ghetto up the roof.

If it's not raining that top is supposed to be off anyway.

It's a jeep, it's nice, it's loud, life is good~!~!~!~!

I certainly don't want to make my roof look like shit, I just wonder how much sound output i'm losing with all the flex, but I may just have to bear with it...

[xAndrew225x 8]

my roof is doing the same thing but its causing nasty rattles. will CLD tiles at least stop the noise?

not trying to hijack your topic

the cars roof isnt plastic whatever though, its metal. (99' corolla )

I would definitely add tiles and some sort of thin foil material with adhesive such as damplifier.

I'm lucky that mine doesn't rattle since its plastic, but im still losing output lol

thanks! how about peal & seal and CLD tiles? ive heard that stuff is an awesome cheap alternative to damplifier and such

[jlftn 11]

from an engineering standpoint, simply using mass to dampen an area is not ideal, bracing is. but in order to do that you would have to screw into your roof, so either way it will not look very good (but bracing would look better than a ton of sound dampener)

also peel n seal is not good, its extremely cheap for a reason and will simply add weight and possibly nasty chemicals to your car (i.e. roofing tar lol)

[xAndrew225x 8]

from an engineering standpoint, simply using mass to dampen an area is not ideal, bracing is. but in order to do that you would have to screw into your roof, so either way it will not look very good (but bracing would look better than a ton of sound dampener)

also peel n seal is not good, its extremely cheap for a reason and will simply add weight and possibly nasty chemicals to your car (i.e. roofing tar lol)

haha thanks. will i be ok with only CLD tiles? this car is temporary and i'm not gonna put alot into sound deadening

[jlftn 11]

the only way to really stiffen thin pieces like that is too add probably a minimum 2 or 3 layers

[jlftn 11]

where r u at in louisiana btw? im in denham springs

[xAndrew225x 8]

where r u at in louisiana btw? im in denham springs

new roads, out in the sticks also. lol

[jlftn 11]

where r u at in louisiana btw? im in denham springs

new roads, out in the sticks also. lol

haha cool deal nice to see some fellow cajuns on SSA

[xAndrew225x 8]

where r u at in louisiana btw? im in denham springs

new roads, out in the sticks also. lol

haha cool deal nice to see some fellow cajuns on SSA

i agree

[Rudeboy 152]

Stiffening isn't a job for any vibration damper - it'd be like breaking your arm and deciding to build a cast out of Band-Aids. It might help a little, but you'd need thousands of them and it wouldn't work well enough to be worth the effort. As has been mentioned, you have to brace a flexing panel. When you introduce enough internal pressure to deform a panel you are taking it well beyond what it was designed to do. It needs to be reinforced. When that's done, you will very likely still have panel resonance and that's where the vibration damper comes in.

The other important point is that vibration dampers and maximizing SPL are not a good mix. Panel resonance produces sound that can be metered. Vibration dampers convert vibration to heat which can't be metered.

All of this explains why we've all heard reports of vibration damper being applied in one case gaining a dB or so and in another case, losing a dB or so. Stiffening and conversion to heat are offsetting mechanisms. It can go either way and is all but impossible to predict ahead of time. Brace without vibration damper and you can be pretty confident that SPL will increase since you aren't losing energy to panel distortion or conversion to heat. It'll sound terrible but sounding good isn't always the goal

[ssh 924]

Stiffening isn't a job for any vibration damper - it'd be like breaking your arm and deciding to build a cast out of Band-Aids. It might help a little, but you'd need thousands of them and it wouldn't work well enough to be worth the effort. As has been mentioned, you have to brace a flexing panel. When you introduce enough internal pressure to deform a panel you are taking it well beyond what it was designed to do. It needs to be reinforced. When that's done, you will very likely still have panel resonance and that's where the vibration damper comes in.

The other important point is that vibration dampers and maximizing SPL are not a good mix. Panel resonance produces sound that can be metered. Vibration dampers convert vibration to heat which can't be metered.

All of this explains why we've all heard reports of vibration damper being applied in one case gaining a dB or so and in another case, losing a dB or so. Stiffening and conversion to heat are offsetting mechanisms. It can go either way and is all but impossible to predict ahead of time. Brace without vibration damper and you can be pretty confident that SPL will increase since you aren't losing energy to panel distortion or conversion to heat. It'll sound terrible but sounding good isn't always the goal

thanks for the informative write up, I was aware that if the vibrations were soaked up by some material that it is converted into heat and thus possibly db loss, I'm not competing and my roof does not actually make any noise while flexing guess I was just looking for an fix to brace it but doesn't sound simple unless I start doing some welding inside

I'll just stick to sound deadening everything else

[inkfx 3]

You could carpet or vinyl the roof after you do what you need to do.

[Julian 641]

Well if you want to go balls deep, you could do a "roll cage" type setup and then bolt the rol lcage to your roof, if it's plastic/fiberglass you can easily drill through it. Then i'd put closed cell foam to keep it from vibrating against the cage.

[Adrian_D 520]

Or buy an XJ, they are made out of metal, minus the hatch but that doesn't flex.

Silly plastic TJ's

Sorry, couldn't help it

[BanginGMC 23]

To control panel resonance do this

To control flex do this

5/6 layers

[Shogen 325]

Bangin.... Are those all CLD tiles??? Are they different sizes or what?

[BanginGMC 23]

Bangin.... Are those all CLD tiles??? Are they different sizes or what?

The first is CLD tiles, the second is Second Skin.. and a shit ton of it lol

[Shogen 325]

oh ok... thanks for clearing that up... was worried for you covering the entire roof with 6" x 10" tiles like that...lolz