our rubbery gunk = "cast skin"?... i think i've figured this stuff out.

[manoverboard987]

our rubbery gunk = "cast skin"?... i think i've figured this stuff out.

ok- pull up a chair, it's kinda long. and my friends tell me i get really long winded when i talk science stuff.

or you can scroll down to the short version, to skip the techno babble.

so up until now, we've all been baffled by why VW would put this poor excuse for a rubbery dashboard coating all over our poor NBs, and, more recently, how we could put back on what is peeling off. for lack of an answer, we've decided to just go strip it off and lay down color in it's place, which, IMHO, is the better choice anyways.

well today i was reading an old issue of a magazine i get called Automotive Engineering International (which is put out by the Society of Automotive Engineers for its members), and found an article i needed about the re-engineering of the C6 Corvette. i'm writing a paper about the hydroforming process responsible for the stiff and lightweight chassis, but thats another story.

the thing in the article that caught my eye was when they started talking about the dashboard. there was a picture in the article and the dash looked exactly like ours does - what with the kinda half-gloss and soft look to it. the caption for the photo reads "...with the instrument and door panels covered with a soft, low-gloss cast skin..."

so i googled "cast skin" and found this page from Delphi which talks about their cast skin instrument panels (which, ironically enough, includes the one in the C6 Corvette). they describe the process as filling a mold that form fits the dashboard piece, filling it with a layer of powdered plastic, and then heating the dashboard piece and pressing it into the junk, resulting in an even coating of whatever plastic you used.

so think powdercoating, except with polymers instead. and no electroplating. actually, it's more like when Dairy Queen dips an ice cream cone in their candy shell stuff. mmmmm.

the pdf at the bottom of the page says that the pluses of this kind of dash covering are that it forms to weird shapes, it cuts down on sun glare, and that it has a "soft, luxurious feel".

anyways, i then scrolled back and saw that they can perform this process with a powdered vinyl, thermoplastic polyurethane, and thermoplastic polyolefin. (thermoplastic just means that once it's heated and set, it can be melted again. the opposite is thermosetting, which, once hardened, will not melt at it's original melting temperature.)

well, we know that the rubbery gunk isn't anyhting like vinyl or hard polyurethane. i had never heard of the last one, so i looked it up too. i found this site, which says "[the stuff in question ] blends of a soft (amorphous) component, such as an ethylene-propylene rubber, with a hard component, such as a crystalline polyolefin." Eureka!

so...

THE SHORT VERSION:

the stuff on our dashboards is not painted on. it's a skin of a blend of rubber and plastic that was basically molded on. that explains why it peels off, and behind it is perfectly unpainted plastic. and that's why dealers are dumbfounded when we ask if we can spray it back on.

why did they use it? well this process fits weird-shaped pieces better than wrapping it in anything for one. also, they used it up on the dash to cut down on glare from the sun. plus it has a "soft, luxurious feel".

as far as why it's only on black and white NBs' door panels? i'm thinking that they thought that white paint was too easily blemished and whatnot and black shiny paint wouldn't go with the already coated dash parts.

(so that's all of it. sorry it was long and probably boring. i wasn't trying to impress anyone or anything, i was just sharing what i found hoping someone would find it interesting and useful. and big ups if you read it all.)

[from Margaritaville...]

Mmmmmmmmmmmm...Dairy Queen...

[jdesigns]

Very interesting! Thanks!

[Lnzbug]

Thanks for the info

[from Margaritaville...]

Well, I guess we need to go over to some Corvette forum now to find out how they get rid of this stuff...

[Lnzbug]

make sure you post your findings here

[lnx-bug]

Interesting information. I never thought that stuff was a paint, but some other type of coating. I have the same stuff on my Ranger and it was pealing just a little under the radio.

I like the matte look of it and if mine starts pealing I would prefer to replace it with something that is also has a matte finish, maybe with a better permanency.

[manoverboard987]

Originally Posted by lnx-bug

I like the matte look of it and if mine starts pealing I would prefer to replace it with something that is also has a matte finish, maybe with a better permanency.

i haven't been out looking for it yet, so i've never seen it, but they say DupliColor makes a black matte "Interior Trim" paint that's made to best stick to plastic interior parts.

of course, if you can get all the rubbery gunk off without sanding or scratching, there's perfectly good black ABS plastic right underneath it.