Author Topic: Trunk sound deadner  (Read 3987 times)

NoYenko

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Trunk sound deadner
« on: November 11, 2012, 04:15:48 PM »
I am looking for some pictures & dimension's of the sound deadner in the trunk on 69 custom interior cars. My car had tar & undercoating all over the trunk that I stupidly scraped off thinking someone added it as a patch. I have one bad picture that doesn't show enough detail. Thanks for your time. George

IZRSSS

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Re: Trunk sound deadner
« Reply #1 on: November 11, 2012, 04:39:13 PM »
Interesting topic. Some discussion here; http://www.camaros.net/forums/showthread.php?t=185813

NoYenko

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Re: Trunk sound deadner
« Reply #2 on: November 11, 2012, 05:26:18 PM »
Thanks for the link. That is interesting concerning under coating sprayed on inside of quarter panels. What I need is information concerning Tar paper on front floor of trunk. George

IZRSSS

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Re: Trunk sound deadner
« Reply #3 on: November 11, 2012, 07:17:11 PM »
Oops  :-[

69Z28-RS

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Re: Trunk sound deadner
« Reply #4 on: November 12, 2012, 06:15:37 PM »
I suspect someone added the tar paper and undercoating in trying to quieten the car; 
My 09C (late) production Z28/RS (with custom cloth interior) does not have any tar paper or undercoating on the floor of the trunk.
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bertfam

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Re: Trunk sound deadner
« Reply #5 on: November 12, 2012, 06:24:34 PM »
Gents, he's referring to the trunk paper that was added by Fisher Body on deluxe interior cars.

This one's a 68, but 69 is basically the same.

Ed


tmodel66

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Re: Trunk sound deadner
« Reply #6 on: November 12, 2012, 06:26:39 PM »
Was that just a little something extra for sound deadening? Or did it have a specific duty?
Daniel  
'69 SS 350/4 speed  Fathom Green--POP

69Z28-RS

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Re: Trunk sound deadner
« Reply #7 on: November 12, 2012, 06:32:07 PM »
My 69 has no evidence of ever having had anything like that...  I've owned it since 1975-76....

Gary
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bertfam

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Re: Trunk sound deadner
« Reply #8 on: November 12, 2012, 06:34:40 PM »
It was designed as a heat barrier to keep the heat from the muffler from melting/deforming the trunk mat.

John has a good picture of his from his 69Z that I'll ask him to post.

Ed

tmodel66

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Re: Trunk sound deadner
« Reply #9 on: November 12, 2012, 06:35:55 PM »
OK Thanks Ed. Makes sense now.
Daniel  
'69 SS 350/4 speed  Fathom Green--POP

NoYenko

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Re: Trunk sound deadner
« Reply #10 on: November 12, 2012, 07:21:01 PM »
Ed, can't thank you enough for the post. That is exactly what I was looking for. What a great site. I would appreciate seeing Johns photo also. Does anyone know if this was only on early cars because someone else with a later built car said his did not have the tar paper. From the stuff I scraped off I assume it is the same as the floor tar paper deadner.George

JohnZ

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Re: Trunk sound deadner
« Reply #11 on: November 12, 2012, 08:16:19 PM »
I can't locate my photo at the moment, but it's just like Ed's photo in reply #5 - all original Deluxe Interior 69's got that mastic deadener pad at the front of the trunk floor.
'69 Z/28
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69Z28-RS

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Re: Trunk sound deadner
« Reply #12 on: November 12, 2012, 09:56:46 PM »
If the purpose of this was 'heat insulation' from the muffler, what is the possibility that when they changed the exhaust configuration, and added the resonators forward of the muffler, that they also deleted this material?   There would be more heat dissipated forward of that point, and less heat at the muffler with that change....

Gary  / 69Z28-RS
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

IZRSSS

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Re: Trunk sound deadner
« Reply #13 on: November 12, 2012, 10:09:10 PM »
Ed, can't thank you enough for the post. That is exactly what I was looking for. What a great site. I would appreciate seeing Johns photo also.

Amazing...why do you think I wanted these guys out-back on the T-shirt? Anyone know if Kurt has a '67  ??? ;)

paceme

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Re: Trunk sound deadner
« Reply #14 on: November 13, 2012, 02:44:03 PM »
If the purpose of this was 'heat insulation' from the muffler, what is the possibility that when they changed the exhaust configuration, and added the resonators forward of the muffler, that they also deleted this material?   There would be more heat dissipated forward of that point, and less heat at the muffler with that change....

Gary  / 69Z28-RS

Gary, all deluxe interior cars were provided the sound deadener( I've seen it on a 10C of 69 and is also on my 9c of 69 car).

Interesting point Ed makes that its purpose was to dissipate heat. My feeling is that the trunk floor deadener purpose was to attenuate any noise / resonance due to the rear axle and suspension in the open trunk area. The material they use I wouldn't classify as heat resistant.

 Ed where is this referenced "It was designed as a heat barrier to keep the heat from the muffler from melting/deforming the trunk mat".

Thanks,
Steve Shauger
Vintage Certification™ Program, Providing Recognition And Status To Unrestored Vehicles. Website www.vintagecertification.com

bertfam

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Re: Trunk sound deadner
« Reply #15 on: November 13, 2012, 03:17:45 PM »
Steve, we (CRG) had a discussion about this a few years ago and I believe the consensus was it was used as a barrier for heat. I could be wrong. John can probably shed more light on this.

Ed

jeff68

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Re: Trunk sound deadner
« Reply #16 on: November 13, 2012, 05:03:46 PM »
Gents, he's referring to the trunk paper that was added by Fisher Body on deluxe interior cars.

This one's a 68, but 69 is basically the same.

Any info on whether a convertible would be different?  My 68 convertible has a piece of 'trunk paper', but it isn't located above the muffler.  It runs front to back on the RH side of the trunk recess.  It appears to be the same shape as the picture Ed posted.  I wonder if this was simply a production mistake.

68 L30 / M20 Convertible
Ash Gold

bertfam

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Re: Trunk sound deadner
« Reply #17 on: November 13, 2012, 05:06:30 PM »
Jeff, can you post a picture of yours?

There's not a lot of information on these, so I can't answer your question. There's not even a part number in the P&A for them. The trunk mat, yes, but not the paper. I've got a lot of cars in the 68 DB with deluxe interiors but NO paper, so I'm not sure why some have it but others don't. Of course, after 45 years, most have probably disintegrated by now!!

I've NO convertibles in the 68 DB with these, so a picture of what you have would be most welcome.

Ed

jeff68

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Re: Trunk sound deadner
« Reply #18 on: November 13, 2012, 05:11:50 PM »
Jeff, can you post a picture of yours?
Ed-  I was just editing my post as you were typing.  See above.

I have a NOS trunk mat I purchased a long time ago.  If it needs protection from the heat, then I definitely want to put something down there.  The original tar-paper type material came apart when it was removed for refinishing the trunk.
68 L30 / M20 Convertible
Ash Gold

69Z28-RS

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Re: Trunk sound deadner
« Reply #19 on: November 13, 2012, 06:20:34 PM »
If the purpose of this was 'heat insulation' from the muffler, what is the possibility that when they changed the exhaust configuration, and added the resonators forward of the muffler, that they also deleted this material?   There would be more heat dissipated forward of that point, and less heat at the muffler with that change....
Gary  / 69Z28-RS
Gary, all deluxe interior cars were provided the sound deadener( I've seen it on a 10C of 69 and is also on my 9c of 69 car).
Interesting point Ed makes that its purpose was to dissipate heat. My feeling is that the trunk floor deadener purpose was to attenuate any noise / resonance due to the rear axle and suspension in the open trunk area. The material they use I wouldn't classify as heat resistant.
Ed where is this referenced "It was designed as a heat barrier to keep the heat from the muffler from melting/deforming the trunk mat".

Steve,  I appreciate your comments, and it is interesting that some later cars had it when mine apparently did not.  My car still has the original trunk paint and trunk mat, but no evidence of anything ever having been glued in that location on the trunk floor. (although there is some deteriorating material falling into the trunk area from the hat rack area above which seems like sound deadening material?)..   I agree with you that a tar-based material would be used for noise purposes, ie. 'panel vibration damping', rather than for heat insulation.  I doubt it would provide any significant heat insulation..

Gary
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

67 RS Ragtop

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Re: Trunk sound deadner
« Reply #20 on: November 13, 2012, 06:45:47 PM »
  My early build '67 convertible with DeLuxe trim also has the "insulator" as shown in previous pictures (not like the last post of a '68).

JohnZ

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Re: Trunk sound deadner
« Reply #21 on: November 13, 2012, 06:58:25 PM »
I agree with you that a tar-based material would be used for noise purposes, ie. 'panel vibration damping', rather than for heat insulation.  I doubt it would provide any significant heat insulation..

Gary

I agree - that heavy mastic pad material is similar to the mastic pads on the floor in the passenger compartment, and they were used for panel damping to eliminate "drumming" of the floor pan. Photo below shows the floor pan mastic pads used in '68; '69 was similar.
'69 Z/28
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KurtS

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Re: Trunk sound deadner
« Reply #22 on: November 18, 2012, 05:04:44 AM »
Can we confirm if the mastic pads were the same all 3 years and between dlx and std interiors? I think they basically are the same as the pic John posted, but the fronts in 68 and 69 don't have that notch removed. Any other differences?
I have a pic of FlowJoe's Firebird floor and it has mastic all down the tunnel and nothing under the front seats, btw.
Kurt S
CRG

NoYenko

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Re: Trunk sound deadner
« Reply #23 on: November 19, 2012, 01:54:08 AM »
Jeff68, That is an interesting picture of your trunk. Shows that your car should have had the tar paper but line worker didn't know where to put it.
Kurt, I don't have as nice a picture as John's but I have three pictures that show the Tar paper installed in my early 69 11A with Deluxe interior. The two bare areas seen, I removed the Tar paper before taking the photo. Hope that helps. George

NoYenko

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Re: Trunk sound deadner
« Reply #24 on: November 19, 2012, 01:55:20 AM »
One more picture.

CVKUEBER

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Re: Trunk sound deadner
« Reply #25 on: November 29, 2012, 05:39:28 PM »
Judging from the hole in the deadener for the spare wheel and tire holdown hook, Possibly there to keep the spare from creating rubbing noises or squeaks against the floor ?
GM parts-tech. Polar Chevrolet White Bear Lake, Mn

Petes L48

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Re: Trunk sound deadner
« Reply #26 on: November 29, 2012, 10:44:38 PM »
Judging from the hole in the deadener for the spare wheel and tire holdown hook, Possibly there to keep the spare from creating rubbing noises or squeaks against the floor ?

That's what I was thinking, and since the coupe had the spare mounted differently I wonder if this was a spare tire sound deadener item rather than a heat shield.  Is there any discernable pattern between LOS and NOR cars?