What kind of plastic is our bumpers made from?

[panzerwagen]

Is it polyurethane? Whats a good repair substance to use to repair a small crack or fill a small dent with? Needs to be flexible, correct?

[Martynf]

I am pretty sure its always coded for recycling as PE

Martyn

[S2central.net]

Dunno the exact material, but given the ability to flex (and the necessity to do so when removing the front bumper), I woudl say a flexible filler is indeed the right answer.

Think we have one or two bodyshop folk on here. Hopefully they can chip in (no pun intended)... Both my bumpers are scratched from a previous owner - I should really get them done sometime this year.

[Crawford_S2]

Any splits or cracks can be welded by a 'specialist' body shop, not easy to find. Dents can be heated to get the worst out then use flexible filler to repair as normal. U-POL do a whole range of plastic repair products, see your local motor factors.

[Henka]

My rear bumper got busted and my cousin used somekind of superglue... Now, I don't remember the name but I'll see him like tomorrow and I'll get back to you.

Don't get all sceptical now. I thought he was pulling my leg when he said that he wasn't going to weld it. This stuff is the bomb. First you clean the surfaces, then you prime them (and you litterally feel your cerebral dissolving!) and then you apply the "glue". The bond itself is (if the procedure is carried out correctly) as strong as the plastic itself. I for one am impressed by it. I'll get back to you with the name of the stuff...

[Stick Insect]

A lot of paint suppliers in the UK offer a split repair service. the bumper can be retextured to look like new.

Eastwood tools do a welding kit I think. It is sold in this country by frost. www.frost.co.uk IIRC

There was a place in stockport which got Subaru bumpers and cut and welded to make custom bumpers.

Their workshop was small and so they used to do this outside, they got more business from the passing trade seeing them working on the bumpers than any other means of advertising.

David

[GlenT]

I agree with Martyn, Polyethylene (PE) not to be confused with Polyurethane (PU)
There will be a moulded code on the inside somewhere ie; >PE<
Sometimes manufacturers now use a PTFE (Polytetraflouroethane) or ABS (Acrylonitrile-butadiene-styrene).

[Lee]

You sure it is PE? Doesn't feel like it.
PTFE is a PITA to paint due to its low surface energy and am really surprised it is used in bumper applications. PTFE 'creeps' also and can only be manufactured into shapes through a sintering process or machining from large blocks so this adds to my surprise.

My first thought was that my RS2 bumper was a styrene of some kind. Another possible is Polyvinylchloride (PVC).

[GlenT]

Actually all three of us were wrong, its a Polybutylenterephthalat >PBTP<. Just crawled under my wifes avant and found the code.
I have seen PTFE body mouldings strangely enough (unpainted though now I think of it) Lee is correct it does have a very slippery surface due to its helical structure. Also used for non lubricated plastic bearings.
Lee your suggestion of PVC would have been my next thought also (if I didn't crawl under and actually check), A good polymer for colouring, fire and weather resistant.

[panzerwagen]

Well lads it seems I've found the perfect repair kit....

for my cracked bumper, it's made by Wurths and it's called Replast. It's a 2 tube kit much like epoxy but is made to be used on flexible plastic bumpers of the type the German mfgs use on their cars. Very easy too use and the results are fantastic. It seems 3M 50/50 is also highly recommended. It appears both companies use the same formula because they sure do look and act the same with exactly the same results.
Both products are strong too. Probably make the bumper stronger at the repair point then the rest of the bumper.