VC Commodore Dry Ice Sound Deadening Removal - Staff Cars

By: David Morley, Unique Cars Magazine

Date: 09.02.2017

Six kilos of dry ice later, the interior of Morley's hillclimb project VC Commodore is prepped for the next step - fitting the roll cage

David Morley's 1980 VC Commodore

Got a nice email the other day. It was from Brown Davis boss David Brown, letting me know that the roll-cage for my hillclimber project was ready to pick up. Great… Except that the rest of the interior was still kind of bog-stock Commodore and that needed to change before the cage was snugged into position and bolted down. Oh sure, the front seats were gone and the carpet was history, but the old girl was still sporting lots of trim bits like a full headliner, B-pillar trims, various seat-belts and enough sound-deadening to sink a battleship. And sink it very quietly.

The seat-belts were a cinch other than the fact that the exposed bits of the threads had become crud-encrusted over the years. So they started to undo freely but by the time they were about halfway out, I was resorting to the breaker bar. Must get one of those battery-operated rattle guns. (Anybody got one? Are they any good?)

Anyways, the headliner was next and, once you’ve unclipped the door-opening trims, you can pull the vinyl away and reach up inside and unclip the metal bows. From there, you pull the headliner out from under the rubber screen seals (mine gave up no probs, but I’d have Stanley-knifed it if it hadn’t) and then you can remove the C-pillar trims and discover the sticky, itchy goop that Holden used to glue them on back in 1980. All up, about five minutes.

So far, so good, but what about that tar-based sound deadener covering almost every square-centimetre of the Commo’s floor? I mean, this stuff is B-grade-horror-movie-evil. You can poke it with a scraper and it yields, but it’ so sticky, it’d take a month to clean it off even with a heat gun. And you don’t want to leave it there because it weighs a ton and if, Gawd forbid, there’s ever a fire, I don’t want molten tar slopping around the footwells. But there’s an old Indian trick I heard about that was deffo worth a try. What you do is you go down to your local industrial supply shop (the place where you buy your welding gas) and you buy an eskyful of frozen carbon-dioxide. That’s dry ice to you and me. The stuff costs about $5.50 a kilo if you take your own esky. I eventually used 6kg in total, but I’d say that’s about the minimum amount you could get away with in an average sized car.

So, what you do is spread the dry-ice pellets all over that tarry crap and wait for the pellets to freeze it and lift it away from the floor as it contracts. If it’s all working, you should hear the tar-mat pop and crack as it freezes and, in places, parts company with the metal. After about 10 minutes, you can give the deadener a sharp crack with a hammer and it should shatter like cold toffee. Then, you give the really stubborn bits a tap or a scrap and bingo, one clean, bare metal floor in, ooh, I’d say a couple of hours. For odd-shaped bits like the trans tunnel, I put the dry ice in a plastic shopping bag and laid it over the hump like saddlebags for the same 10 minutes or so.

Okay, you need to work with all the doors open because the dry ice goes from a solid, straight to a gas, meaning it could, in a confined space, displace the oxygen I’m so fond of, leaving me with nothing worth breathing. Also, these pellets are colder than a mother-in-law’s kiss, and contact with bare skin will leave you with a burn. Big, gauntlet-style welding gloves are the ticket and don’t forget the eye protection. If there’s any dry ice left over, you just make sure there are no kids or animals around, chuck it out on the back lawn and in an hour or so, it’ll just go away. So, yeah, you have to have your brain in gear when using dry ice, but as an alternative to spending days on my hands and knees with a heat gun and scraper, this is definitely a trick worth remembering. And remember where you read it first… Oh, and a big thanks to Scotty Taylor on Street Machine for the heads-up on this.

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