Weird Plastic

Ringmaster · 11-06-17, 02:13 PM

Folks,

Not an Audi issue I'm afraid.

My uncle's 2001 BMW 3 series has a black plastic console that runs from the gear selector leaver, backwards under the driver/passenger central arm rest. The plastic appears to be deteriorating on the surface and the plastic below appears pristine. If I wanted to spend ages gently scraping the surface I'm sure I could restore its appearance significantly.

It looks like they tried to use a plastic that gave an impression of leather but ended up with something that is very soft, easily scratched and seems to be ageing quickly.

Anyone had a similar experience or can suggest a way of dissolving/polishing the knackered surface plastic?

4v6 · 11-06-17, 05:33 PM

Ive seen a similar thing on other plastics, on a Kenwood home entertainment system.
The volume control was of a type of almost spongy plastic , at least it felt very slightly spongy until the surface went all sticky and yukky, breaking down, ive seen it on lots of other things also.
Dont know what the solution is tho.

sinbin5t · 11-06-17, 05:44 PM

I tried to dissolve some of that, result ? well it turned to goo that wouldn't come off and then set rock hard overnight

Needless to say the said item had to go in the bin.

SwallownAmazon · 30-06-17, 10:16 PM

Quote:

Originally Posted by 4v6

Ive seen a similar thing on other plastics, on a Kenwood home entertainment system.
The volume control was of a type of almost spongy plastic , at least it felt very slightly spongy until the surface went all sticky and yukky, breaking down, ive seen it on lots of other things also.
Dont know what the solution is tho.

The "spongy" feel is a coating called "soft feel" and was developed by industrial paint manufacturers to make cheap plastic look a bit classier. Problem now is that such coatings are increasingly water-borne (NOTE - Not water-based) and don't last as long as solvent-borne coatings. They absorb oils from your skin when you handle them and soften/go sticky. Nothing to do except replace the part or scrape off the manky coating leaving the cheap plastic on display.
(Knowledge from my background as a chemist in the surface coatings industry.

)

4v6 · 01-07-17, 12:21 PM

Quote:

Originally Posted by SwallownAmazon

The "spongy" feel is a coating called "soft feel" and was developed by industrial paint manufacturers to make cheap plastic look a bit classier. Problem now is that such coatings are increasingly water-borne (NOTE - Not water-based) and don't last as long as solvent-borne coatings. They absorb oils from your skin when you handle them and soften/go sticky. Nothing to do except replace the part or scrape off the manky coating leaving the cheap plastic on display.
(Knowledge from my background as a chemist in the surface coatings industry.

)

Ahh cheers for that, didnt know anything about the stuff other than it goes gooey over time.

jimh · 01-07-17, 08:48 PM

The same stuff was used on my A4 and my S8, and it goes the same way.
You can remove it with one of those green plastic scouring pads used for washing dinner plates (so I hear), soaked in IPA.
It's messy, so ideally you want to remove the part from the car and wear gloves.

You then have options of leaving it bare plastic if it looks ok, or vinyl wrapping it, or spraying it with plastidip. You have to remove all the old coating to wrap or plastidip it though as if the surface it not smooth, any imperfections will show through.

If the part can be removed and is a suitable shape, I think matt black vinyl wrapping is probably the best option. I would only use plastidip if the part is too awkward a shape to use vinyl.

11-06-17, 05:33 PM	#2
4v6 Ex Member Classic Audi Club Member Join Date: Dec 2007 Posts: 5,565	Ive seen a similar thing on other plastics, on a Kenwood home entertainment system. The volume control was of a type of almost spongy plastic , at least it felt very slightly spongy until the surface went all sticky and yukky, breaking down, ive seen it on lots of other things also. Dont know what the solution is tho.

11-06-17, 05:44 PM	#3
sinbin5t 4 ring whore! Classic Audi Club Member Join Date: Jan 2010 Location: Where a spike points skywards Posts: 12,960	I tried to dissolve some of that, result ? well it turned to goo that wouldn't come off and then set rock hard overnight Needless to say the said item had to go in the bin.

01-07-17, 08:48 PM	#6
jimh Grown up member Classic Audi Club Member Join Date: Dec 2008 Posts: 122	The same stuff was used on my A4 and my S8, and it goes the same way. You can remove it with one of those green plastic scouring pads used for washing dinner plates (so I hear), soaked in IPA. It's messy, so ideally you want to remove the part from the car and wear gloves. You then have options of leaving it bare plastic if it looks ok, or vinyl wrapping it, or spraying it with plastidip. You have to remove all the old coating to wrap or plastidip it though as if the surface it not smooth, any imperfections will show through. If the part can be removed and is a suitable shape, I think matt black vinyl wrapping is probably the best option. I would only use plastidip if the part is too awkward a shape to use vinyl.