This month we got rolling...
This month we got rolling with a spray-in sound deadener called VB-1X.Using the SG-1 gun (available from Cascade Audio, see photo above) theinstallation was as easy--and as simple to clean up--as last month'sThermaGuard application.
In the July 2006 issue, we lined the inside of our project '87 with CascadeAudio's ThermaGuard to help keep the heat out of the cockpit. Thismonth, we took the install to the next level, with Cascade's VB-1X, aspray-on sound deadener that's similar to a truck-bed coating. Thevolume differences were instantly noticeable, and thanks to a RadioShack-issue decibel meter and the Neil Peart drum solo "Der Trommler,"we know the extent of the changes.
Following the final coat of VB-1X, we went a step further and added someof Cascade's V-Max material to the trouble areas inside the C4--namely,the transmission tunnel, rear hatch, and B-pillar. Measuring 12x32inches, the V-Max sheets are made from rubber-backed flexible aluminumand stick in place after being cut to size. The sound-deadening resultsfrom these pieces were just as dramatic, and after we lined our car witha carpet kit from Corvette Central (an install we will cover in thefuture), The Son of Zombie was as soundproof as it's going to get.
But while this upgrade may sound like a sure thing, we discovered a fewproblems with the VB-1X that remain unaddressed. For example, accordingto the instructions, the liner should be waterproof after seven days ofcure time. After nearly three times that span, however, we discoveredthat the material had not developed the desired water-repellingproperties. In fact, the affected areas had actually become lesseffective, the material having changed composition from soft and rubberyto hard and flat. Was our particular batch of VB-1X defective? We'reunsure, but the material's inability to withstand just a few drops ofwater is troubling. We'll let you know how things work out in the monthsahead.
We sprayed the rear hatch...
We sprayed the rear hatch area first, followed by the floor, transmission tunnel, and firewall.
Our final noise-attenuation readings will have to wait until we finishfinal assembly. Keep in mind that the car is still pretty "open air" atthe moment. For now, just follow along for more information on whatCascade Audio can do for your Corvette.
SOUND TEST RESULTS
| Condition | Readings | Difference |
| Bare Floor | 82 dB Max | NA |
| VB-1X | 78 dB Max | -4 db |
| V-Max | 74 dB Max | -4 db |
| Carpet | 71 dB Max | -3 db |
Total: -11 dB*(*With car partially disassembled)
 In our last report on this...  In our last report on this subject, we had just finished spraying Cascade Audio's ThermaGuard into the interior of our C4 project car, The Son of Zombie. For more on this job, see the July issue. |  At each step we measured our...  At each step we measured our progress with a little help from this Radio Shack-issued decibel meter. |  Measuring 12x30 inches, these...  Measuring 12x30 inches, these "cut to size" sheets are of a rubber-backed flexible-aluminum material that sticks in place. |
 With the firewall finished,...  With the firewall finished, we moved on to the V-Max sheeting. |  Each coat was allowed to cure...  Each coat was allowed to cure fully before the next, leaving the final product to look like this... |  ...All those red spots represent...  ...All those red spots represent holes for screws and other hardware. We had covered them with tape to keep the spray from clogging them. |
 The trans tunnel was firs...  The trans tunnel was first... |  ...followed by a few strategic...  ...followed by a few strategic spots in the flooring... |  ...and, lastly, the hatch...  ...and, lastly, the hatch. |
 Nearly a month later (we got...  Nearly a month later (we got a little busy), we returned to replace our firewall pad. A big thanks goes to the Tampa-based Corvette Shop and Supplies for finding this little-requested piece of OEM equipment for us. It slipped in place as the original did and was secured via two plastic retaining tabs, which are available at most auto-parts stores. |  Neil Peart of Rush bangs away...  Neil Peart of Rush bangs away on the skins in his drum solo "Der Trommler." We got our results by playing the music through a set of laptop speakers positioned underneath the floorpan. Once the car is fully assembled, we will provide final numbers and compare them with the readings taken before the C4 died of heart failure. For now, you can at least see there was a difference--an 11db difference to be precise. | |